Neutron Network

Neutron Network

Neutron, an essential OpenStack cloud computing platform component, provides a flexible and scalable networking service. Designed to meet the needs of modern cloud environments, Neutron plays a crucial role in creating and managing virtual networks. In this blog post, we will explore the fundamentals of Neutron networks and their significance in cloud networking.

Neutron Network is an abstraction layer allowing tenants (users) to create and manage virtual networks, routers, subnets, and other network-related resources. Neutron enables users to define and control their network infrastructure programmatically by providing a set of APIs and plugins.

Table of Contents

Highlights: Neutron Network

Application Program Interface

Neutron’s pluggable application program interface ( API ) architecture enables the management of network services for container networking in public or private cloud environments. The API allows users to interact with neutron networking constructs, such as routers and switches, enabling instance reachability. The OpenStack Neutron and OpenStack network types were initially built into Nova but lacked flexibility for advanced designs. It was helpful for large Layer 2 networks, but most environments require better multi-tenancy with advanced load balancing and firewalling functionality.

Decoupled Layer 3 Approach

The limited networking functionality gave Neutron, which offers a decoupled Layer 3 approach. It operates an Agent-Database model where the API receives and sends calls to agents installed locally on the hosts. Without this efficiency, there won’t be any communication and connectivity between your host’s platforms, which can sometimes affect productivity.

For additional pre-information, you may find the following helpful:

  1. OpenStack Neutron Security Groups
  2. Kubernetes Network Namespace
  3. Service Chaining



OpenStack Network Types.

Key Neutron Network Discussion points:


  • Introduction to Neutron Networking.

  • Discussion on OpenStack Network Types.

  • Virtual switches, routing and advanced services with Neutron.

  • Neutron High Availability.

  • Discussion on traffic flow.

Back to Basics: Neutron Network

Key Features and Benefits:

1. Network Virtualization: Neutron Network leverages network virtualization technologies such as VLANs, VXLANs, and GRE tunnels to create isolated virtual networks. This allows tenants to have complete control over their network resources without interference from other tenants.

2. Scalability: Neutron’s distributed architecture can scale horizontally to accommodate many virtual networks and instances. This ensures that cloud environments can handle increased workloads without compromising performance.

3. Network Segmentation: Neutron Network supports network segmentation, allowing tenants to partition their virtual networks based on specific requirements. This enables better network isolation, security, and performance optimization.

4. Flexible Network Topologies: Neutron provides the flexibility to create a variety of network topologies, including flat networks, VLAN-based networks, and overlay networks. This adaptability empowers users to design their networks according to their unique needs.

5. Integration with Security Services: Neutron Network integrates seamlessly with OpenStack’s security services, such as Firewall-as-a-Service (FWaaS) and Virtual Private Network-as-a-Service (VPNaaS). This integration enhances network security by providing additional layers of protection.

6. Load Balancing and VPN Services: Neutron Network offers load balancing services, allowing users to distribute network traffic across multiple instances for improved performance and reliability. Additionally, it supports VPN services to establish secure connections between different networks or remote users.

Neutron Network Architecture:

Under the hood, Neutron Network consists of several components working together to provide a robust networking service. The main elements include:

– Neutron API: Provides a RESTful API for users to interact with Neutron Network and manage their network resources.

– Neutron Core Plugin: The central component responsible for handling network-related requests and managing network plugins.

– Neutron Agents: Various agents, such as the DHCP agent, L3 agent, and OVS agent, ensure the smooth operation of the Neutron Network by handling specific tasks like DHCP allocation, routing, and switching.

– Network Plugins: Neutron supports multiple plugins, such as the Open vSwitch (OVS) plugin and the Linux Bridge plugin, which provide different network virtualization capabilities and integrate with various networking technologies.

OpenStack Network Types

Logical network information is stored in the database. It’s the role of plugins and agents to extract the data and carry out the necessary low-level functions to pin the virtual network, enabling instance connectivity. For example, the Open vSwitch agent converts information in the Neutron database to Open vSwitch flow while maintaining the local flows to match the network design following topology changes. Agents and plugins build the network based on the logical data model. The screenshot below illustrates the agent-to-host installation.

openstack network types

OpenStack Network Types

  • Neutron Networking: Network, Subnets, and Ports

Neutron consists of 4 elements that form the foundation for OpenStack Network Types. The configuration consists of the following entities – Networks, Subnets, and Ports. A network is a standard Layer 2 broadcast domain in which subnets and ports are assigned. A subnet is an IPv4 or IPv6 address block ( IPAM – IP Address Management) posted to a network.

A port is a connection point with properties similar to a physical port, except that it is virtual. Ports have media access control addresses ( MAC ) and IP addresses. All port information is stored in the Neutron database used by plugins/agents to stitch and build the virtual infrastructure. 

 

OpenStack Network Types: Neutron networking features

Neutron networks enable core networking and the potential for a lot more once the appropriate extension and plugin are activated. Extensions enhance plugins to provide additional network functionality. Due to its pluggable architecture, Neutron can be extended with 3rd party open-source or proprietary products, for example, an SDN OpenDaylight controller for advanced centralized functionality. 

While Neutron does offer an API for network interaction, it does not provide an API to manage the network. Integrating an SDN controller with Neutron enables a centralized viewpoint and management entity for the entire network infrastructure, not just individual pieces.

Some vendor plugins complement Neutron, while others completely replace it. Advancements have been made to Neutron in an attempt to make it more “production-ready,” but some of these features are still at the experimental stage. There are bugs in all platforms, but generally, early-release features should be kept in nonproduction environments.

OpenStack Network Types: Virtual switches, routing, and advanced services

Virtual switches are software switches that connect VM instances at Layer 2. Any communication outside that boundary requires a Layer 3 router, either physical or virtual. Neutron has built-in support for Linux Bridges and Open vSwitch virtual switches. Overlay networking, the foundation for multi-tenancy for cloud computing, is supported in both. 

Layer 3 routing permits external connectivity and connectivity between VMs in different subnets. Routing is enabled through IP forwarding rules, IPtables, and network namespaces.

IPtables provide ingress/egress filtering throughout different parts within the network (for example, perimeter edge or local compute ), namespaces provide network stack isolation, and IP forwarding rules provide forwarding. Firewalling and security services are based on Security Groups or/FWaaS (FireWall-as-a-Service).

They can be used in conjunction with each other for better defense in depth. Both operate with IPtables but differ in network placement.

Security group IPtable rules are configured locally on ports corresponding to the compute node hosting the instance. Implementation is close to the actual workload, offering finer-grained filleting. Firewall IPtable rules are at the network’s edge on Neutron routers ( namespaces ), filtering perimeter traffic.

Load balancing enables requests to be distributed to multiple instances. Dispersing load to multiple hosts offers advantages similar to the traditional world. The plugin is based on open-source HAProxy. Finally, VPNs allow operators to extend the network securely with IPSec-based VPN tunnels. 

 

OpenStack Network Types: Virtual network preparation

The diagram below displays the initial configuration and physical interface assignments for a standard neutron deployment. The reference model consists of a controller, network, and compute nodes. The compute nodes are restricted to provide compute resources, while the controller/network node may be combined or separated for all other services.

Separating services on the compute nodes allows compute services to be scaled horizontally. It’s common to see the controller and networking node operating on a single host.

Service OpenStack

The number and type of interfaces depend on how good you feel about combining control and data traffic. Networking can function with just one interface, but splitting the different types of network traffic into several separate interfaces is good.

OpenStack Network Types uses four types of traffic – Management, API, External, and Guest. If you are going to separate anything, it’s recommended to physically separate management and API traffic from all other types of traffic. Separating the traffic to different interfaces splits the control from data traffic—a tick from the security auditors’ box.

Neutron Reference Design

In the preceding diagram, Eth0 is used for the management and API network, Eth1 for overlay traffic, and Eth2 for external and Tenant networks ( depending on the host ). The tenant networks ( Eth2 ) reside on the compute nodes, and the external network resides on the controller node ( Eth2 ).

The controller Eth2 interface uses Neutron routers for external network traffic to instances. In certain Neutron Distributed Virtual Routing ( DVR ) scenarios, the external networks are at the compute nodes.

 

Plugins and drivers

Neutron networking operates with the concept of plugins and drivers. Neutrons core plugin can be either ML2 or a vendor plugin. Before ML2, Neutron was limited to a single-core plugin at any given time. The ML2 plugin introduces the concept of type and mechanism drivers.

Type drivers represent type-specific network states and support local, flat, vlan, gre, and vxlan network types. Mechanism drivers take information from the type driver and ensure its implementation correctly.

There are agent-based, controller-based, and Top-of-Rack models of the mechanism driver. The L2 population, Open vSwitch, and Linux bridge are the most popular. In addition, the mechanism driver arena is a popular space for vendors’ products.

 

Linux Namespaces

The majority of environments out there require some multi-tenancy. Cloud environments would be straightforward if built for only one customer or department. In reality, this is never the case. Multi-tenancy within Neutron is based on Linux Namespaces. Namespace offers a completely isolated stack to do what you want. They enable a logical copy of the network stack supporting overlapping IP assignments.

A lot of Neutron networking is made possible with the use of namespaces and the ability to connect them.

We have a qdhcp namespace, qrouter namespace, qlbass namespace, and additional namespaces for DVR functionality. Namespaces are present on nodes running the respective agents. The following command displays different routing tables for NAMESPACE-A and the global namespace, illustrating the ability of network stack isolation.

Linux namespace

OpenStack Network Types: Virtual network infrastructure

Local, Flat, VLAN, VXLAN, and GRE networks

Neutron networking supports Local, Flat, VLAN, VXLAN, and GRE networks. Local networks are isolated networks. Flat networks do not incorporate any VLAN tagging. On the other hand, VLAN networks use the standard. Q tagging ( IEEE 802.1Q ) to segregate traffic. VXLAN networks encapsulate Layer 2 traffic over IP using VTEP and VXLAN network identifier ( VNI ).

GRE is another type of Layer 2 over Layer 3 overlay. GRE and VXLAN accomplish the same goal of emulation over pure IP but have different ways of doing so – VXLAN uses UDP, and GRE traffic uses IP protocol 47.

Layer 2 data is transported from an end host, encapsulated over IP to the egress switch that sends the data to the destination host. With an underlay and overlay approach, you have two layers to debug when something goes wrong.

openstack network types

OpenStack Network Types: Virtual Network Switches

The first step in building a virtual network is to make the virtual switching infrastructure. This acts as the base for any network design, whether virtual or physical. Virtual switching provides connectivity to and from the virtual instances, building the concrete for advanced networking services. The first piece of the puzzle is the virtual network switches.

Neutron networking includes built-in support for the Linux Bridge and Open vSwitch. Both are virtual switches but operate with some significant differences. The Linux bridge uses VLANs to tag traffic, while the Open vSwitch uses flow rules to manipulate traffic before forwarding.

Instead of mapping the local VLAN ID to a physical VLAN ID, the local ID is added or stripped from the Ethernet header by flow rules.

The “brctl show” command displays the Linux bridge. The bridge ID is automatically generated based on the NIC, and the bridge name is based on the UUID of the corresponding Neutron network. The “ovs-vsctl show” command displays the Open vSwtich. It has a slightly more complicated setup, with the br-int ( integration bridge ) acting as the main center point of connections.

openstack network types

Neutron uses the bridge, 802.1q, and vxlan kernel modules to connect instances with the Linux bridge. Bridge and Open vSwitch kernel modules are used for the Open vSwitch. The Open vSwitch uses some userspace utilities to manage the OVS database. Most networking elements are connected with virtual cables, known as veth cables. What goes in one end must come out; the other best describes a virtual cable.

Veths connect many elements, including namespace to the namespace, Open vSwitch to Linux bridge, and Linux bridge to Linux bridge, all combined with veth cables. The Open vSwitch uses additional particular patch ports to connect Open vSwitch bridges. The Linux bridge doesn’t use patch ports.

The Linux Bridge and Open vSwitch can be used to complement each other. For example, when Neutron Security Groups are enabled, instances connect to the Linux and Open vSwitch Integration bridges with a veth cable. The workaround is caused by the inability to place IPtable rules ( needed by security groups ) on tap interfaces connected to Open vSwitch bridge ports.

 

Neutron network and network address translation (NAT)

Neutron employs the concept of Network Address Translation (NAT) to predict inbound and outbound translations. The concept of NAT stays the same in the virtual world, either by modifying an IP packet’s source or destination address. Neutron employs two types of translations – one-to-one and one-to-many.

One-to-one translations utilize floating IP addresses, and many-to-one is a Port Address Translation ( PAT ) style design where floating IP is not used. F

Floating IP addresses are externally routed IP addresses that directly map instances and an external IP address. The term floating comes from the fact that they can be modified on-the-fly between instances. They are associated with a Neutron port logically mapped to an instance. Ports can have multiple IP addresses assigned.

    • SNAT refers to source NAT, which changes the source IP address to appear as the externally connected interface.
    • Floating IPs are called Destination NAT ( DNAT ), which change the source and destination IP address depending on traffic direction.

The external network connected to the virtual router is the network from which floating IPs are derived. The default behavior is to source NAT traffic from instances that lack floating IP. Instances that use source NAT can not accept traffic initiated externally. If you want traffic created externally to hit an instance, you must use a one-to-one mapping with a floating IP.

Neutron High Availability

Standalone router

The most accessible type of router to create in Neutron is a standalone router. As the name suggests, it lacks high availability. Routers created with Neutron exist on namespaces that reside on the nodes running the L3 agent. It is the role of the Layer 3 agent to create the network namespace representing the routing function.

A virtual router is essentially a network namespace called the qrouter namespace. The qrouter namespace uses routing tables to forward traffic and IPtable rules to dictate how traffic is translated.

neutron networking

A virtual router can connect to two different types of networks. Either a single external provider network or one or more tenant networks. The interface to an external provider bridge network is “qg” and to a tenant network bridge is a “qr” interface. The tenant network traffic is routed from the “qr” interface to the “qg” interface for onward external forwarding.

 

Virtual router redundancy protocol

VRRP is pretty simple and offers highly available and redundant default gateways or the next hop of a route. The namespaces ( routers ) are spread across multiple hosts running the Layer 3 agent. Multiple router namespaces are created and distributed among the Layer 3 agents. VRRP operates with a Linux keepalive instance. Each runs a “keepalive” service to detect the other’s availability.

The keepalive service is a Linux keepalive tool that uses VRRP internally. It is the role of the L3 agent to start the keepalive instance on every namespace. A dedicated HA network allows the routers to talk to each other. There are split-brain and MAC flapping issues; as far as I understand, it’s still an experimental feature.

 

Distributed virtual routing 

DVR eliminates the bottleneck caused by the Layer 3 agent and distributes most of the routing function across multiple compute nodes. This helps isolate failure domains and increases the high availability of the virtual network infrastructure. With DVR, the routing function is not centralized anymore but decentralized to the compute nodes. The compute nodes themselves become one big router.

DVR routers are spawned on the compute nodes, and all the routing gets done closer to the workload. Distributing routing to the compute nodes is much better than having a central element perform the routing function.

There are two types of modes: dvr and dvr_snat. Mode dvr_snat handles north-to-south SNAT traffic. Mode dvr handles North to south DNAT traffic ( floating IP) and all east-to-west traffic.

Key Points:

  • East-West traffic ( server to server ) previously went through the centralized network node. DVR pushes this down to the compute nodes hosting the VMs.
  • North-South traffic with floating IPs ( DNAT ) is routed directly by the compute nodes hosting the VMs.
  • North-South traffic without floating IP ( SNAT ) is routed through a central network node. Some complications exist in distributing the SNAT functions to the local compute nodes.
  • There is a requirement for DNAT that computes nodes using floating IPs that require direct external connectivity.

 

East-west traffic between instances

East-to-west traffic (traditional server-to-server) refers to local communication, such as traffic between a frontend and the backend application tier. DVR enables each compute node to host a copy of the same router. The router namespace created on each compute node has the same interface, MAC, and IP settings.

East West traffic

DVR East to WestNEWDVR East to West

The qr interfaces within the namespaces on each compute node share the same IP and MAC address. But how is this possible?? One can assume the distribution of ports would raise IP clashes and MAC flapping. Neutron cleverly uses routing tables and Open vSwitch flow rules to enable this type of forbidden sharing.

Neutron allocates a unique MAC address to each compute node. This MAC is used whenever traffic leaves the node.

Once traffic leaves the virtual router, Open vSwitch rules rewrite the source MAC address with the unique MAC address allocated to the source node. All the manipulation is done before and after traffic leaves or enters, so the VM is unaware of any rewriting and operates as usual.

 

Centralized SNAT 

Source SNAT is used when instances do not have a floating IP address. Neutron decided not to distribute SNAT to the compute nodes and keep it central similar to the legacy model. Why do they decide to do this when DVR distributes floating IP for north-south traffic?

Decentralizing SNAT would require an address from the external network on every node providing the SNAT service. This would consume a lot of addresses on your external network.

centralized SNAT

The Layer 3 agent configured as dvr_snat server is the centralized SNAT function. Two namespaces get created for the same router – a regular qrouter namespace and a SNAT namespace. The SNAT and qrouter namespace are created on the centralized nodes, either the controller or the network node.

The qrouter namespaces on the controller and compute nodes are identical. However, even though the router is attached to an external network, there are no qg interfaces. The qg interfaces are now inside the SNAT namespace. There is also now a new interface called the sg. This is used as an extra hop.

 

Packet Flow

  • A VM without a floating IP sends a packet to an external destination.
  • Traffic arrives at the regular qrouter namespace on the actual node and gets redirected to the SNAT namespace on the central node.
  • To redirect traffic from the qrouter namespace to the SNAT namespace is carried out by clever tricks with source routing and multiple routing tables.

 

North-to-south traffic with Neutron floating IP

In the legacy world, floating IPs are configured as /32 prefixes on the router’s external device. The one-to-one mapping between the VM IP address and the floating IP address is used so external devices can initiate traffic externally to the internal instance.

North-to-south traffic with floating IP is now handled with another namespace, called the fip namespace. The new fip namespace is created by the Layer 3 agent and represents the external network to which the fip belongs.

distributed virtual routing

Every router on the compute node is hooked into the new fip namespace with a veth pair. As already mentioned, veth pairs are commonly used to connect namespaces. One side of the other pair is in the router namespace (rfp). The other end belongs to the fip namespace (fpr).

Whenever a layer 3 agent creates a new floating IP, a new rule is specific to that IP. Neutron adds the fixed IP of the VM to the rules table with an additional new routing table.

 

Packet Flow

  • When a VM with a floating IP sends traffic to an external destination, it arrives at the qrouter namespace.
  • The IP rules are consulted, showing a default route for that source to the next hop. IPtables rules kick in, and the source IP is translated to the floating IP.
  • Traffic is forwarded out the rfp interface and arrives at the fpr interface at the fip namespace.
  • The fip namespace uses a default route to forward traffic out the ‘fg’ device to its external destination.

Traffic in the reverse direction requires Proxy ARP, so the fip namespace answers requests for the floating IP configured on the router’s router namespace ( not the fip namespace ). In addition, proxy ARP enables hosts ( fip namespace) to answer ARP requests intended for other hosts ( qrouter namespace ).

 

Summary: Neutron Network

Neutron Network, a fundamental component of OpenStack, is pivotal in connecting virtual machines and providing networking services within a cloud infrastructure. In this blog post, we delved into the intricacies of the Neutron Network and explored its key features and benefits.

Section 1: Understanding Neutron Network Architecture

Neutron Network operates with a modular architecture comprising various components such as agents, plugins, and drivers. These components work together to enable network virtualization, creating virtual networks, subnets, and routers. By understanding the architecture, users can leverage the full potential of the Neutron Network.

Section 2: Network Virtualization with Neutron

One of the standout features of Neutron Network is its ability to provide network virtualization. By abstracting the underlying physical network infrastructure, Neutron empowers users to create isolated virtual networks tailored to their specific requirements. This flexibility allows for enhanced security, scalability, and agility within cloud environments.

Section 3: Neutron Network Extensions

Neutron Network offers many extensions that cater to diverse networking needs. From load balancers and firewalls to virtual private networks (VPNs) and quality of service (QoS) policies, these extensions provide additional functionality and customization options. We explored some popular extensions and their use cases.

Section 4: Neutron Network in Action: Use Cases

To truly comprehend the value of Neutron Network, it’s essential to explore real-world use cases where its capabilities shine. This section delved into scenarios such as multi-tenant environments, hybrid cloud deployments, and network function virtualization (NFV). By examining these use cases, readers can envision the practical applications of the Neutron Network.

Conclusion:

Neutron Network is a vital networking component within OpenStack, enabling seamless connectivity and virtualization. With its modular architecture, extensive feature set, and wide range of use cases, Neutron Network empowers users to build robust and scalable cloud infrastructures. As cloud technologies evolve, Neutron Network ensures efficient and reliable networking within cloud environments.

OpenDaylight (ODL)

OpenDaylight

 

OpenDaylight

OpenDaylight, an open-source platform, has emerged as a game-changer in the networking industry. OpenDaylight has revolutionized network automation and software-defined networking (SDN) with its robust features and capabilities. In this blog post, we will explore the critical aspects of OpenDaylight and its significant contribution to network management and innovation.

OpenDaylight is an open-source, modular platform that enables developing and deploying SDN and network functions virtualization (NFV) solutions. It provides a flexible and scalable framework for building software-defined networks, allowing network engineers and developers to configure, manage, and monitor network resources efficiently.

Highlights: OpenDaylight

  • The Role of Abstraction

What is the purpose of the service abstraction layer in the open daylight SDN controller? Traditional networking has physical boxes physically connected. Each device has a data and control plane function. The data plane is elementary and forwards packets as quickly as possible. The control plane acts as the point of intelligence and sets the controls necessary for data plane functionality.

  • SDN Controller

With the OpenDaylight SDN controller, we drag the control plane out of the box and centralize it on a standard x86 server. What happens in the data plane does not change; we still forward packets. It still consists of tables that look at packets and perform some action. What changes are the mechanisms for how and where tables get populated? All of which share similarities with the OpenStack SDN controller.

  • OpenDaylight

OpenDaylight is the central control panel that helps to populate these tables that move data through the network as you see fit. It consists of an open API allowing the control of network objects as applications. So to start the core answers, what is the purpose of the service abstraction layer in the open daylight SDN controller? Let’s look at the OpenDaylight and OpenStack SDN controller integrations.

 



OpenDaylight SDN Controller.

Key OpenDaylight Discussion points:


  • Introduction to OpenDaylight SDN Controller.

  • Discussion on the OpenDaylight integrations.

  • Complications with Neutron Networking.

  • The Neutron Networking model.

  • Highlighting OpenDaylight project components.

 

For additional pre-information, you may find the following helpful:

  1. OpenStack Architecture

 

  • A key point: Ansible and OpenDaylight

The Ansible architecture is simple, flexible, and powerful, with a vast community behind it. Ansible is capable of automating systems, storage, and of course, networking. However, Ansible is stateless, and a stateful view of the network topology is needed from the network engineer’s standpoint. There is where OpenDaylight joins the game.

As an open-source SDN controller and network platform, OpenDaylight translates business APIs into resource APIs, and Ansible networking performs its magic in the network. The Ansible architecture, specifically the Ansible Galaxy tool that ships with Ansible, can be used to install OpenDaylight. To install OpenDaylight on your system, you can use an Ansible playbook.

 

Back To Basics With OpenDaylight

OpenDaylight Integration: OpenStack SDN Controller

The single API is used to configure heterogeneous hardware. OpenDaylight integrates tightly with the OpenStack SDN controller, providing the central controller element for many open-source clouds. It was born shortly after Neutron, and the two projects married as soon as the ML2 plugin was available in Neutron. OpenDaylight is not intended to replace the Neutron Networks but adds and provides better functionality and network management. OpenDaylight Beryllium offers a Base, Virtualized, and Service Provider edition.

OpenDaylight (ODL) understands the network at a high level, running multiple applications on top of managing network objects. It consists of a Northbound interface, Middle tier, and Southbound interface. The northbound interface offers the abstraction of the network. It exposes interfaces to those writing applications to the controller, and it’s here you make requests with high-level instructions.

The middle tier interprets and compiles the request, enabling the southbound interface to action the network. The type of southbound protocol is irrelevant to the northbound API. It’s wholly abstracted and could be OpenFlow, OVSDB, or BGP-LS. The following screen displays generic information for the OpenDaylight Lithium release.

 

What is the purpose of the service abstraction layer in the open daylight sdn controller

Key Features and Capabilities:

1. OpenDaylight Controller: At the core of OpenDaylight is its controller, which acts as the brain of the network. The controller provides a centralized network view, enabling administrators to manage resources, define network policies, and dynamically adapt to changing network conditions.

2. Northbound and Southbound Interfaces: OpenDaylight offers northbound and southbound interfaces that facilitate communication between the controller and network devices. The northbound interface enables applications and services to interact with the controller, while the southbound interface allows the controller to communicate with network devices, such as switches and routers.

3. Modular Architecture: OpenDaylight’s modular architecture provides flexibility and extensibility. It allows developers to add or remove modules based on specific network requirements, ensuring the platform remains lightweight and adaptable to various network environments.

4. Comprehensive Set of Protocols: OpenDaylight supports various industry-standard protocols, including OpenFlow, NETCONF, and BGP. This compatibility ensures seamless integration with existing network infrastructure, making adopting OpenDaylight in diverse network environments easier.

Benefits of OpenDaylight:

1. Network Automation: OpenDaylight simplifies network management by automating repetitive tasks like provisioning and configuration. This automation significantly reduces the time and effort required to manage complex networks, allowing network engineers to focus on more strategic initiatives.

2. Enhanced Network Visibility: With its centralized control and management capabilities, OpenDaylight provides real-time visibility into network performance and traffic patterns. This visibility allows administrators to promptly identify and troubleshoot network issues, leading to improved network reliability and performance.

3. Scalability and Flexibility: OpenDaylight’s modular architecture and support for industry-standard protocols enable seamless scalability and flexibility. Network administrators can quickly scale their networks to accommodate growing demands and integrate new technologies without disrupting existing infrastructure.

4. Innovation and Collaboration: Being an open-source platform, OpenDaylight encourages collaboration and innovation within the networking community. Developers can contribute to the project, share ideas, and leverage their collective expertise to build cutting-edge solutions that address evolving network challenges.

 

Complications with Neutron Network

Initially, OpenStack networking was built into Nova ( nova-network ) and offered little network flexibility. It was rigid and significant if you only wanted a flat Layer 2 network. Flat networks are fine for small designs with single application environments, but anything at scale will reach CAM table limits. VLANs also have theoretical hard stops.

Nova networking was represented as a second-class citizen in the compute stack. Even OpenStack Neutron Security Groups were dragged to another device and not implemented at a hypervisor level. This was later resolved by putting IPtables in the hypervisor, but we still needed to be on the same layer 2 domain.

 

Limitation of Nova networking

Nova networking represented limited network functionality and did not allow tenants to have advanced control over network topologies. There was no load balancing, firewalling, or support for multi-tenancy with VXLAN. These were some pretty big blocking points.

Suppose you had application-specific requirements, such as a vendor-specific firewall or load balancer, and you wanted OpenStack to be the cloud management platform. In that case, you couldn’t do this with Nova. OpenStack Neutron solves all these challenges with its decoupled Layer 3 model.

 

  • A key point: Networking with Neutron

Networking with Neutron offers better network functionality. It provides an API allowing the interaction of network constructs ( router, ports, and networks ), enabling advanced network functionality with features such as DVR, VLXAN, Lbass, and FWass.

It is pluggable, enabling integration with proprietary and open-source vendors. Neutron offers more power and choices for OpenStack networking, but it’s just a tenant-facing cloud API. It does not provide a complete network management experience or SDN controller capability.

 

The Neutron networking model

The Neutron networking model consists of several agents and databases. The neutron server receives API calls and sends the message to the Message Queue to reach one of the agents. Agents on each compute node are local, actioning and managing the flow table. They are the ones that carry out the orders.

The Neutron server gets a response from the agents and records the new state of the network in the database. Everything connects to the integration bridge ( br-int ), where traffic gets tagged with VLAN ID and handed off to the other bridges, for example, br-tun for tunneling traffic.

Each network/router uses a Linux namespace for isolation and overlapping IP addresses. The complex architecture comprises many agents on all compute, network, and controller nodes. It has scaling and robustness issues you will only notice when your system goes down.

Neutron is not an API for managing your network. If something is not working, you need to check many components individually. There is no specific way to look at the network in its entirety. This would be the job of an OpenDaylight SDN controller or an OpenStack SDN controller.

 

OpenDaylight Project Components

OpenDaylight is used in conjunction with Neutron. It represents the controller that sits on top and offers abstraction to the user. It bridges the gap between the user’s instructions and the actions on the compute nodes, providing the layer that handles all the complexities. The Neutron doesn’t go away and works together with the controller.

Neutron gets an ODL driver installed that communicates with a Northbound interface that sits on the controller. The MD-SAL (inventory YANG model) in the controller acts as the heart and communicates to both the controller OpenFlow and OVSDB components.

OpenFlow and OVSDB are the southbound protocols configuring and programming local compute nodes. The OpenDaylight OVSDB project is the network virtualization project for OpenStack. The following displays OpenvSwtich connection to OpenDaylight. Notice the connection status is “true.” For this setup, the controller and switch are on the same node.

 

opendaylight sdn controller
Diagram: Opendaylight sdn controller and OpenvSwtich connection.

 

The role of OpenvSwitch

OpenvSwitch is viewed as the workhorse forOpenDaylight. It is programmable and offers advanced features such as NetFlow, sFlow, IPFIX, and mirroring. It has extensive flow matching capabilities – Layer 1 ( QoS priority, Tunnel ID), Layer 2 ( MAC, VLAN ID, Ethernet type), Layer 3 (IPv4/v6 fields, ARP), Layer 4 ( TCP/UDP, ICMP, ND) with many chains of action such as output to port, discard and packet modification. The two main userspace components are the ovsdb-server and the ovs-vswitchd.

The ODL OVSDB manager interacts with the ovsdb-server, and the ODL OpenFlow controller interacts with the ovs-vswitchd process. The OVSDB southbound plugin plugs into the ovsdb-server. All the configuration of OpenvSwitch is done with OVSDB, and all the flow adding/removing is done with OpenFlow.

 

OpenDaylight OpenFlow forwarding

OpenStack traditional Layer 2 and Layer 3 agents use Linux namespaces. The entire separation functionality is based on namespaces. OpenDaylight doesn’t use namespaces; you only have a namespace for the DHCP agent. It also does not have a router or operate with a network stack—the following displays flow entries for br0. OpenFlow ver1.3 is in use.

Openvswitch bridge

OpenFlow rules are implemented to do the same job as a router. For example, MAC is changing or TTL decrementation. ODL can be used to manipulate packets, and the Service Function Chain (SFC) feature is available for advanced forwarding. Then you can use service function chaining with service classifier and service path for path manipulation.

OpenDaylight service chaining has several components. The job of the Service Function Forwarder (SFF) is to get the flow to the service appliance; this can be accomplished with Network Service Header (NSH) or using some tunnel with GRE or VXLAN.

 

Conclusion:

OpenDaylight has emerged as a powerful platform for network automation and SDN, empowering organizations to unlock the full potential of their networks. Its robust features, modular architecture, and support for industry-standard protocols make it a valuable asset for network administrators and developers. By embracing OpenDaylight, organizations can streamline their network management processes, enhance network visibility, and foster innovation. As the networking landscape continues to evolve, OpenDaylight will undoubtedly play a vital role in shaping the future of network automation and software-defined networking.

 

what is the purpose of the service abstraction layer in the open daylight sdn controller?

wide-open-spaces-2021-08-31-22-42-30-utc

Neutron Networks

 

openstack lbaas architecture

 

Neutron Networks

In today’s digital age, connectivity has become essential to our personal and professional lives. As the demand for seamless and reliable network connections grows, businesses seek innovative solutions to meet their networking needs. One such solution that has gained significant attention is Neutron Networks. In this blog post, we will delve into Neutron Networks, exploring its features, benefits, and how it is revolutionizing connectivity.

Neutron Networks is an open-source networking project within the OpenStack platform. It acts as a networking-as-a-service (NaaS) solution, providing a programmable interface for creating and managing network resources. Unlike traditional networking methods, Neutron Networks offers a flexible framework that allows users to define and control their network topology, enabling greater customization and scalability.

 

Highlights: Neutron Networks

  • The Role of OpenStack Networking

OpenStack networking and neutron networks offer virtual networking services and connectivity to and from Instances. It plays a significant role in OpenFlow and SDN adoption. The Neutron API manages the configuration of individual networks, subnets, and ports. It enhanced the original Nova-network implementation and introduced support for 3rd party plugins, such as Open vSwitch (OVS) and Linux bridge.

OVS and LinuxBridge provide Layer 2 connectivity with VLANs or Overlay encapsulation technologies, such as GRE or VXLAN. Neutron is pretty basic, but their capability is gaining momentum with each distribution release with the ability to include an OpenStack neutron load balancer.

 

You may find the following helpful post for pre-information:

  1. OpenStack Neutron Security Groups
  2. Neutron Network
  3. OpenStack Architecture

 



OpenStack Neutron Load Balancer.

Key Neutron Networks Discussion Points:


  • Introduction to Neutron networks and what is involved.

  • Highlighting the different components of Neutron networks.

  • Discussing the switching methods.

  • Technical details load balancing and OpenStack lbaas architecture.

  • A final note on HAProxy.

 

Back to Basics with Neutron Networks

OpenStack Networking

OpenStack Networking is a pluggable, API-driven approach to control networks in OpenStack. OpenStack Networking exposes a programmable application interface (API) to users and passes requests to the configured network plugins for additional processing. A virtual switch is a software application that connects virtual machines to virtual networks. The virtual switch operated at the data link layer of the OSI model, Layer 2. A considerable benefit to Neutron is that it supports multiple virtual switching platforms, including Linux bridges provided by the bridge kernel module and Open vSwitch.

 

  • A key point: Ansible and OpenStack

Ansible architecture offers excellent flexibility and can be used ways to leverage Ansible modules and playbook structures to automate frequent operations with OpenStack. With Ansible, you have a module to manage every layer of the OpenStack architecture. At the time of this writing, Ansible 2.2 includes modules to call the following APIs

  • Keystone: users, groups, roles, projects
  • Nova: servers, keypairs, security groups, flavors
  • Neutron: ports, network, subnets, routers, floating IPs
  • Ironic: nodes, introspection
  • Swift Objects
  • Cinder volumes
  • Glance images

 

Key Features of Neutron Networks:

a) Network Abstraction: Neutron Networks abstract the underlying network infrastructure, allowing users to manage and configure virtual networks without worrying about the complexities of the physical infrastructure.

b) Multi-Tenancy Support: Organizations can create isolated virtual networks with Neutron Networks, granting multiple tenants secure access to their network resources within a shared infrastructure.

c) Extensibility: Neutron Networks supports various plugins and drivers, enabling seamless integration with various networking technologies and devices.

d) Load Balancing and Firewalling: Neutron Networks offer built-in load balancing and firewalling capabilities, empowering organizations to enhance network security and optimize traffic distribution.

Benefits of Neutron Networks:

a) Improved Agility: By providing a programmable interface, Neutron Networks enables organizations to quickly adapt their network infrastructure to changing business requirements, reducing time-to-market for new applications and services.

b) Enhanced Security: Neutron Networks’ multi-tenancy support and built-in firewalling capabilities ensure secure isolation and protection of network resources, minimizing the risk of unauthorized access and data breaches.

c) Scalability and Flexibility: With Neutron Networks, businesses can quickly scale their network infrastructure up or down based on demand, ensuring optimal performance and resource utilization.

d) Cost Optimization: Neutron Networks eliminates the need for expensive physical networking equipment by leveraging virtualization, reducing capital and operational expenses associated with traditional networking approaches.

Real-World Applications of Neutron Networks:

Neutron Networks has found applications across various industries, including:

a) Cloud Service Providers: Neutron Networks enables cloud service providers to offer customers customizable and scalable networking solutions, enhancing the overall cloud experience.

b) Software-Defined Networking (SDN): Neutron Networks are a vital component of SDN architectures, allowing organizations to control and manage their network infrastructure programmatically.

c) Internet of Things (IoT): Neutron Networks provide a reliable and scalable networking solution for IoT deployments, facilitating seamless communication and data transfer between connected devices.

 

Neutron Networks

Neutron networks support a wide range of networks. Including Flat, Local, VLAN, and VXLAN/GRE-based networks. Local networks are isolated and local to the Compute node. In a FLat network, there is no VLAN tagging. VLAN-capable networks implement 802.1Q tagging; segmentation is based on VLAN tags. Similar to the physical world, hosts in VLANs are considered to be in the same broadcast domain, and inter-VLAN communication must pass a Layer 3 device.

GRE and VXLAN encapsulation technologies create the concept known as overlay networking. Network Overlays interconnect layer 2 segments over an Underlay network, commonly an IP fabric but could also be represented as a Layer 2 fabric. Their use case derives from multi-tenancy requirements and the scale limitations of VLAN-based networks.

 

The virtual switches: Open vSwitch and Linux Bridge

Open vSwitch and Linux Bridge plugins are monolithic and cannot be used simultaneously. A new plugin, introduced in Havana, called Modular Layer 2 ( ML2 ), allows the use of multiple Layer 2 plugins simultaneously. It works with existing OVS and LinuxBridge agents and is intended to replace the associated plugins.

OpenStack foundations are pretty flexible. OVS and other vendor appliances could be used parallel to manage virtual networks in an OpenStack Neutron deployment. Plugins can replace OVS with a physically managed switch to handle the virtual networks. 

 

Open vSwitch

The OVS bridge is a popular software-based switch orchestrating the underlying virtualized networking infrastructure. It comprises a kernel module, a vSwitch daemon, and a database server. The kernel module is the data plane, similar to an ASIC on a physical switch. The vSwitch daemon is a Linux process creating controls so the kernel can forward traffic.

The database server is the Open vSwitch Database Server ( OVSDB) and is local on every host. OVS consists of 4 distinct elements, – Tap devices, Linux bridges, Virtual Ethernet cables, OVS bridges, and OVS patch ports. Virtual Ethernet cables, known as veth mimic network patch cords. They connect to other bridges and namespaces (namespaces discussed later). An OVS bridge is a virtualized switch. It behaves similarly to a physical switch and maintains MAC addresses.

 

openstack networking

 

OpenStack networking deployment details

A few OpenStack deployment methods exist, such as Maas, Mirantis Fuel, Kickstack, and Packstack. They all have their advantages and disadvantages. Packstack suits small deployments, Proof of Concepts, and other test environments. It’s a simple Puppet-based installer. It uses SSH to connect to the nodes and invokes a puppet run to install OpenStack.

Additional configurations can be passed to Packstack via an answer file. As part of the Packstack run, a file called keystonerc_admin is created. Keystone is the identity management component of OpenStack. Each component in OpenStack registers with Keystone. It’s easier to source the file than those values in the source file are automatically placed in the shell environment.

Cat this file to see its content and get the login credentials. You will need this information to authenticate and interact with OpenStack.

openstack neutron load balancer

 

OpenStack lbaas Architecture

Neutron networks 

OpenStack is a multi-tenant platform; each tenant can have multiple private networks and network services isolated through network namespaces. Network namespaces allow tenants to have overlapping networks with other tenants. Consider a namespace to an enhanced VRF instance connected to one or more virtual switches. Neutron uses a “qrouter”“glbaas” and “qdhcp” namespace.

Regardless of the network plugins installed, you need to install the neutron-server service at a minimum. This service will expose the Neutron API for external administration. It is configured to listen to API calls on ALL addresses by default. This can be changed in the Neutron.conf file by editing the bind_host – 0.0.0.0.

  • “Neutron configuration file is found at /etc/neutron/neutron.conf”

OpenStack networking provides extensions that allow the creation of virtual routers and virtual load balancers with an OpenStack neutron load balancer. Virtual routers are created with the neutron-l3-agent. They perform Layer 3 forwarding and NAT.

A router default performs Source NAT on traffic from an instance destined to an external service. Source NAT modifies the packet source appearing to upstream devices as if it came from the router’s external interface. When users want direct inbound access to an instance, Neutron uses what is known as a Floating IP address. It is similar to the analogy of Static NAT; one-to-one mapping of an external to an internal address. 

  • “Neutron stores its L3 configuration in the l3_agent.ini files.”

The following screenshot displays that the L3 agent must first be associated with an interface driver before you can start it. The interface driver must correspond to the chosen network plugin, for example, LinuxBridge or OVS. The crudini commands set this.openstack lbaas architecture

OpenStack neutron load balancer

The OpenStack lbaas architecture consists of the neutron-lbaas-agent and leverages the open-source HAProxy to load balance traffic destined to VIPs. HAProxy is a free, open-source load balancer. LBaaS supports third-party drivers, and they will be discussed in later posts.

Load Balancing as a service enables tenants to scale their applications programmatically through Neutron API. It supports basic load-balancing algorithms and monitoring capabilities.

The OpenStack lbaas architecture load balancing algorithms are restricted to round-robin, least connections, and source IP. It can do basic TCP connect tests for monitoring and complete Layer 7 tests that support HTTP status codes.

 

HAProxy installation

As far as I’m aware, it doesn’t support SSL offloading. The HAProxy driver is installed in one ARM mode, which uses the same interface for ingress and egress traffic. It is not the default gateway for instances, so it relies on Source NAT for proper return traffic forwarding. Neutron stores its configuration in the lbaas_agent.ini files.

Like the l3 agent, it must associate with an interface driver before starting it – “crudini –set /etc/neutron/lbaas_agent.ini DEFAULT interface_driver neutron.agent.linux.interface.OVSInterfaceDriver”. Both agents use network namespaces for isolated forwarding and load-balancing contexts.

 

Conclusion:

In conclusion, Neutron Networks has emerged as a game-changer in the networking world, offering organizations the flexibility, scalability, and security they need in today’s digital landscape. With its innovative features and benefits, Neutron Networks is paving the way for a new era of connectivity, empowering businesses to unlock the full potential of their network infrastructure. As the demand for reliable and efficient networking solutions continues to grow, Neutron Networks is well-positioned to shape the future of connectivity.

openstack neutron load balancer

openstack foundations

Openstack Architecture in Cloud Computing

OpenStack Architecture in Cloud Computing

Cloud computing has revolutionized businesses' operations by providing flexible and scalable infrastructure for hosting applications and storing data. OpenStack, an open-source cloud computing platform, has gained significant popularity due to its robust architecture and comprehensive services.

In this blog post, we will explore the architecture of OpenStack and how it enables organizations to build and manage their own private or public clouds.

At its core, OpenStack comprises several interconnected components, each serving a specific purpose in the cloud infrastructure. The architecture follows a modular approach, allowing users to select and integrate the components that best fit their requirements.

Table of Contents

Highlights: OpenStack Architecture in Cloud Computing

The role of decoupling

The key to cloud computing is decoupling virtual resources from physical ones. The ability to abstract processors, memory, etc., from the underlying hardware enables on-demand/elastic provisioning and increased efficiency. This abstraction process has driven the cloud and led to various popular cloud flavors such as IaaS – Infrastructure-as-as-Service, PaaS – Platform-as-as-Service, and SaaS – Software-as-as-service, a base for OpenStack foundations.

The fundamentals have changed, and the emerging way of consuming I.T. ( compute, network, storage ) is the new “O.S.” for the data center in the cloud. The cloud cannot operate automatically and needs a management suite to control and deploy service-oriented infrastructures. Different companies deploy different teams specialized only in managing cloud computing. Those without an in-house team get it outsourced by firms like Global Storage. 

Related: You may find the following post of interest:

  1. OpenStack Neutron Security Groups
  2. OpenStack Neutron
  3. Network Security Components
  4. Hyperscale Networking



Openstack Architecture in Cloud Computing.

Key Openstack Architecture in Cloud Computing Discussion Points:


  • Introduction to OpenStack architecture in cloud computing and what is involved.

  • Highlighting the components of cloud computing.

  • Critical points on OpenStack foundations and operations.

  • Technical details on the use of APIs.

  • Technical details for the OpenStack deployment details.

Back to Basics: Cloud Adoption.

The adoption of cloud technology has transformed how companies run their IT services. By leveraging new strategies for resource use, several cloud solutions came into play with different categories: private, public, hybrid, and community.

OpenStack falls into the private cloud category. However, deploying OpenStack is still a difficult step, which requires a good understanding of its beneficial returns to a given organization concerning automation, orchestration, and flexibility.

The main components of OpenStack are:

1. Nova: Nova is the compute service responsible for managing and provisioning virtual machines (VMs) and other instances. It provides an interface to control and automate the deployment of instances across multiple hypervisors.

2. Neutron: Neutron is a networking service that enables creating and managing virtual networks within the cloud environment. It offers a range of networking options, including virtual routers, load balancers, and firewalls, allowing users to customize their network configurations.

3. Cinder: Cinder provides block storage to OpenStack instances. It allows users to create and manage persistent storage volumes, which can be attached to cases for data storage. Cinder supports various storage backends, including local disks and network-attached storage (NAS) devices.

4. Swift: Swift is an object storage service that provides scalable and durable storage for unstructured data. It enables users to store and retrieve large amounts of data, making it suitable for applications that require high scalability and fault tolerance.

5. Keystone: Keystone serves as the identity service for OpenStack, providing authentication and authorization mechanisms. It manages user credentials and assigns access rights to the various components and services within the cloud infrastructure.

6. Glance: Glance is an image service that enables users to discover, register, and retrieve virtual machine images. It provides a catalog of images that can be used to launch instances, making it easy to create and manage VM templates.

7. Horizon: Horizon is the web-based dashboard for OpenStack, providing a graphical user interface (GUI) for managing and monitoring the cloud infrastructure. It allows users to perform administrative tasks like launching instances, managing networks, and configuring security settings.

These components work together to provide a comprehensive cloud computing platform that offers scalability, high availability, and efficient resource management. OpenStack’s architecture is designed to be highly modular and extensible, allowing users to add or replace components per their specific requirements.

SDN Abstraction

These platforms rely on a new networking architecture known as software-defined networking. Traditional networking relies on manual administration, and its culture is based on a manual approach. Networking gear is managed box by box, and administrators maintain singular physical network hardware and connectivity. SDN, on the other hand, abstracts the network.

The switching infrastructure may still contain physical switch components but is managed like one switch. The data plane is operated as an entire entity rather than a loosely coupled connected device. SDN approach is often regarded as a prerequisite and necessary foundation for scalable cloud computing.

 

OpenStack Architecture in Cloud Computing

OpenStack Fundations and Origins

OpenStack Foundations is a software platform for orchestrating and automating data center environments. It provides APIs enabling users to create virtual machines, network topologies, and scale applications to business requirements. It does not just let you control your cloud; you may make it available to customers for unique self-service and management.

It’s a collection of projects (each has a specific mission) to create a shared cloud infrastructure maintained by a community. It enables any organization type to build its public or private cloud stack. A key differentiator from OpenStack and other platforms is that it’s open-source, run by an independent community continually updating and reviewing publicly accessible information. The key to its adoption is that customers do not fear vendor lock-in.

The pluggable framework is supported by multiple vendors, allowing customers to move away from the continuous path of yearly software license renewal costs. There is real momentum behind it. The lead-up to OpenStack and cloud computing started with Amazon Web Service (AWS) in 2006. They offered a public IaaS and virtual instances with an API. However, there was no SLA or data guarantee, so research academies mainly used it.

NASA and Rackspace

Historically, OpenStack was founded by NASA and Rackspace. NASA was creating a project called Nebula, which was used for computing. Rackspace was involved in a storage project ( object storage platform ) called Cloud Files. The two projects mentioned above led to a community of collaborating developers working on open projects and components.

There are plenty of vendors behind it and across the entire I.T. stack. For servers, we have Dell and H.P.; Storage consists of NetApp and SolidFire; Networking has Cisco and Software with VMware and IBM.

Initially, OpenStack foundations started with three primary services: NOVA computer service, SWIFT storage service, and GLANCE virtual disk image service. Soon after, many additional services, such as network connectivity, were added. The initial networking suffered simple implementations, providing only basic networking via Linux Layer 2 VLANs and IPtables.

Now, with the Neutron networks, you can achieve a variety of advanced topologies and rich network policies. Most networking is based on tunneling ( GRE or VXLAN ). Tunnels are used within the hypervisor, so it fits nicely with multi-tenancy. Tunnels are created between the host over the Layer 3 network within the hypervisor. As a result, tenancy V.M.s can spin up where they want and communicate over the tunnel.

 

What is an API?

The application programming interface ( API ) is the engine under the cloud hood. The messenger takes requests, tells the systems what you want to do, and then returns the response to you—ultimately creating connectivity.

openstack foundations

Each core project (compute, network, etc.) will expose one or more HTTP/RESTful interfaces for public or managed access. This is known as a Northbound REST API. Northbound API faces some programming interfaces. It conceptualizes lower-level detail functions. Southbound faces the forwarding plane and allows components to communicate with a lower-level part.

For example, a southbound protocol could be OpenFlow or NETCONF. Northbound and southbound are software directions from the reference point of the network operating systems. We now have an East-West interface. At the time of writing, this protocol is not fully standardized, but eventually, it will be used to communicate between federations of controllers for state synchronization and high availability.

 

OpenStack Architecture: The Foundations

  1. OpenStack Compute – Nova is comparable to AWS EC2. She is used to provisioning instances for applications.
  2. OpenStack Storage – Swift is comparable to AWS S3. Provides object storage functions for application objects.
  3. OpenStack Storage – Cinder is comparable to AWS Elastic Block Storage. Provides persistent block storage functions for stateless instances.
  4. OpenStack Orchestration – Heat is comparable to AWS Cloud formation. Orchestrates deployment of cloud services
  5. OpenStack Networking – Neutron Network is comparable to AWS VPC and ELB. Creates networks, topologies, ports, and routers.

There are others, such as Identity, Image Service, Trove, Ceilometer, and Sahara.

Each OpenStack foundation component has an API that can be called from either CURL, Python, or CLI. CURL is a command-line tool that lets you send HTTP requests and receive responses. Python is a widely-used programming language, and within the OpenStack ecosystem, Python automates scripts to create and manage resources in your OpenStack cloud. Finally, command-line interfaces (CLI) can access and send requests to APIs.

 

OpenStack Architecture & Deployment

OpenStack has a very modular design, and the diagram below displays key OpenStack components. Logically, it can be divided into three groups: a) Control, b) Network, and c) Compute. All of the features use a database or a message bus. The database can either be MySQL, MariaDB, or PostgreSQL. The message bus can be RabbitMQ, Qpid, and ActiveMQ.

The messaging and database could run on the same control node for small or DevOps deployments but could be separated for redundancy. The cloud controller on the left consists of numerous components, which are often disaggregated into separate nodes. It is the logical interface to the cloud and provides the API service.

Openstack Deployment

The network controller includes the networking service known as Neutron. It offers an API for orchestrating network connectivity. Extension plugins provide additional network services such as VPNs, NAT, security firewalls, and load balancing. Generally, it is separate from the cloud controller as traffic may flow through it. The compute nodes are the instances. This is where the application instances are deployed. 

 

Leverage vagrant 

A vagrant is a valuable tool for setting up Dev OpenStack environments to automate and build virtual machines ( with OpenStack ). It’s a wrapper around a virtualization platform, so you are not running the virtualization in Vagrant. The Vagrant V.M. gives you a pure environment to work with as it isolates dependencies from other V.M. applications. Nothing can interfere with the V.M., offering full testing scope. An excellent place to start is Devstack. It’s the best tool for setting up small single-node non-production/testing installs.

Summary: OpenStack Architecture in Cloud Computing

In the fast-evolving world of cloud computing, OpenStack has emerged as a powerful open-source platform that enables efficient management and deployment of cloud infrastructure. Understanding the architecture of OpenStack is essential for developers, administrators, and cloud enthusiasts alike. This blog post delved into the various components and layers of OpenStack architecture, providing a comprehensive overview of its inner workings.

Section 1: OpenStack Components

OpenStack comprises several key components, each serving a specific purpose in the cloud infrastructure. These components include:

1. Nova (Compute Service): Nova is the heart of OpenStack, responsible for managing and provisioning virtual machines (VMs) and controlling compute resources.

2. Neutron (Networking Service): Neutron handles networking functionalities, providing virtual network services, routers, and load balancers.

3. Cinder (Block Storage Service): Cinder offers block storage capabilities, allowing users to attach and manage persistent storage volumes to their instances.

4. Swift (Object Storage Service): Swift provides scalable and durable object storage, ideal for storing large amounts of unstructured data.

Section 2: OpenStack Architecture Layers

The OpenStack architecture is structured into multiple layers, each playing a crucial role in the overall functioning of the platform. These layers include:

1. Infrastructure Layer: This layer comprises the physical hardware resources such as servers, storage devices, and switches that form the foundation of the cloud infrastructure.

2. Control Layer: The control layer comprises services that manage and orchestrate the infrastructure layer. It includes components like Nova, Neutron, and Cinder, which control and coordinate resource allocation and network connectivity.

3. Application Layer: At the topmost layer, the application layer consists of software applications and services that run on the OpenStack infrastructure. These can range from web applications to databases, all utilizing the underlying resources OpenStack provides.

Section 3: OpenStack Deployment Models

OpenStack offers various deployment models to cater to different needs and requirements. These models include:

1. Public Cloud: OpenStack is operated and managed by a third-party service provider in a public cloud deployment, offering cloud services to multiple organizations or individuals over the internet.

2. Private Cloud: A private cloud deployment involves setting up an OpenStack infrastructure exclusively for a single organization. It provides enhanced security and control over data and resources.

3. Hybrid Cloud: A hybrid cloud deployment combines both public and private clouds, allowing organizations to leverage the benefits of both models. This provides flexibility and scalability while ensuring data security and control.

Conclusion:

OpenStack architecture is a complex yet robust framework that powers cloud computing environments. Understanding its components, layers, and deployment models is crucial for effectively utilizing and managing OpenStack infrastructure. Whether you are a developer, administrator, or simply curious about cloud computing, exploring OpenStack architecture opens up a world of possibilities for building scalable and efficient cloud environments.