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Intent-based fabric management with Ansible

Tutorial: Intent-based management with Ansible

Ansible is today the lingua franca for many network engineers to automate the configuration of network devices. Due to its simplicity and low entry barrier, it is a popular choice for network automation that features modular and reusable automation tasks available to network teams.

Broadly speaking, there are two common approaches to network automation with Ansible:

1. Smaller, per-device configuration management using Ansible modules
2. And a more broad and generic, per-service/role (or even per-fabric) configuration management using higher-level Ansible abstractions like roles and custom modules.

The first approach is the most common and straightforward one, as it is easy to get started with and requires little to no development skills. Just take the off-the-shelf module provided by the Ansible community or a vendor and start moving configuration tasks from the CLI snippets saved in a notebook to a playbook.
While sounding simple, this approach can become a maintenance nightmare as the number of devices and configuration tasks grows. The playbook will become a long list of tasks that are hard to maintain and reuse.

This is when the second approach comes into play. It requires a deeper understanding of Ansible concepts, but it is more scalable and maintainable in the long run. The idea is to abstract the configuration tasks into reusable Ansible roles and use variables to pass the configuration parameters to the roles. This way, the playbook becomes a list of roles that are applied to the devices in the inventory.

When roles are designed in a way that make services provisioned on all the devices in the inventory, the playbook becomes an intent-based service provisioning tool. To provide a practical example of using Ansible to manage the configuration of an SR Linux fabric with the intent-based approach leveraging the official Ansible collection for SR Linux we created a comprehensive tutorial that covers A to Z the steps required to start managing a fabric in that way - Intent-based management with Ansible tutorial.

We are eager to hear your thoughts on that approach and the tutorial itself. Please drop a comment below or open an issue in the GitHub repository if you have any questions or remarks.

Single Tier Datacenters - Evolving Away From Multi-chassis LAG

Multi-Chassis LAG (MC-LAG) was a welcome technology that helped enterprises move away from xSTP based L2 networks. It solved many of the issues inherent to xSTP networks, like underutilized links, long convergence times, and layer 2 loops. It became a common design pattern in many datacenters at the access and aggregate layers.

And as with any other technology, MC-LAG started to show its deficiencies as the datacenter networks continued to evolve. The need for a more scalable, interoperable and simpler solution led to the development of EVPN Multihoming (EVPN-MH) design. In this blog post we will discuss how a small-scale, single-rack datacenter deployment can benefit from EVPN-Multihoming-based design.
We finish the post by introducing a path to scale up from a single-rack deployment to a multi-rack deployment.

NANOG88: gNMI and ChatGPT To Troubleshoot EVPN Datacenter Fabrics

NANOG88

I am happy that during NANOG88 conference, I had the privilege of presenting a tutorial that I am now pleased to inform you is available for viewing by the wider audience on YouTube.

NANOG88 provided a remarkable platform for knowledge exchange and collaboration among esteemed professionals in the field of networking and Internet operations. I was fortunate to have the opportunity to contribute to this extraordinary event by delivering this tutorial.

Are you interested in learning about EVPN-VXLAN technologies for Datacenters and creating a virtual network lab using containerlab? Then check this tutorial where we will guide you through the process.

We will cover everything from installing the necessary requirements for Python scripting using libraries like pyGNMI, a powerful tool used for operating and troubleshooting network elements with access via gRPC, and with the help of ChatGPT. We will show how to configure many network elements at once using Go Templates and gNMIc. By the end of the tutorial, you will have tips and tricks to perform various network automation tasks in your network datacenter environment and troubleshoot any issues that arise.

This tutorial is suitable for both experienced network engineers and beginners who want to enhance their knowledge of network design and operation with tools like GNMI, python and ChatGPT. The Information is available at Repo

Don't miss out on this opportunity to improve your network engineering abilities and take your skills to the next level.

Participants: Mauricio (Mau) Rojas

gNxI Browser - A documentation UI for Openconfig gRPC services

In the past year, there has been a lot of buzz around gRPC and Openconfig services. Network engineers started to hear more g-acronyms: gNMI, gNOI, gRIBI. The bravest ones started to play with them, and those who like to live on the edge even started to use them in production. But the majority of network engineers are still not familiar with these technologies. The lack of tools to explore and understand these new technologies is one of the reasons for this.

You probably know that in srl-labs we strive for quality tools, and we are not afraid to build them ourselves. The famous gnmic, gnoic, gribic by Karim Radhouani are stellar examples of our effort to make gRPC and Openconfig services more accessible to network engineers.

Today we are happy to announce another initiative by our team - gnxi.srlinux.dev - a documentation UI for Openconfig gRPC services. It is a simple web application that allows you to explore Openconfig gRPC services and their protobuf definitions.

We hope that it will help network engineers to get familiar with gRPC and Openconfig services and we wanted to tell you how we built it.

Official Ansible collection for SR Linux

Ever since we released a tutorial that showed how to use Ansible's URI module with SR Linux, we couldn't shake off the feeling that we would need to do more with Ansible. And we did.
We are happy to announce that we have released an official Ansible collection for SR Linux - nokia.srlinux - that has four modules inside and leverages JSON-RPC interface.

In this blog post, we would like to share some details about our design decisions and why we think this collection is a great addition to the Ansible ecosystem.

Event-Driven Automation With Nokia’s SR Linux Event Handler Framework

Packet Pushers

In this Tech Bytes podcast we talk about Event Handler, a new automation feature in Nokia’s SR Linux network OS that lets you automatically run scripts to fix problems when an event occurs.

We discuss:

• SR Linux’s modular design
• The new Event Handler Framework
• How Event Handler works
• Use cases for network engineers and operations teams

Participants: Roman Dodin

SR Linux logging with ELK

Join the discussion: LinkedIn post · Twitter thread

In a not-so-distant past, manually extracting, parsing, and reading log files produced by network elements was standard practice for a sysadmin. With arcane piping of old-but-good grep, awk, and sed tools, one could swiftly identify a problem in a relatively large system. This was a viable approach for quite some time, but it became prey to a massive scale.

Today's network infrastructures often count thousands of elements, each emitting log messages. Getting through a log collection of this size with CLI tools designed decades ago might not be the best tactic. As well as correlating logs between network elements and application logs might be impossible without software solutions built with such use cases in mind.

The unprecedented growth in the application world boosted the development of multi-purposed centralized/cloud data collectors that make observability and discovery over huge data sets a reality. Elasticsearch / Logstash / Kibana (or ELK for short) is one of the most known open-source stacks tailored for the collection and processing of various documents, logs included.

To enable the processing of captured logs and deliver performant and robust search analytics log collectors rely on structured data. Unfortunately, the networking world is infamous for iterating slowly. For example, an outdated and informational Syslog interface still dominates the networking space when it comes to managing and transferring logs. Syslog RFC3164⁴ was not designed to allow extensible structured payloads, which adds a fair share of problems with integrating such systems with modern log collectors.

This post explains how an SR Linux-powered DC fabric can be integrated with a modern logging infrastructure based on the Elasticsearch / Logstash / Kibana stack to collect, transform, handle, and view logs.

SR Linux Syntax Highlighting with Pygments

For a very long time, I wanted to make a syntax highlighter for the SR Linux command-line interface mainly because I belong to a cohort of readers who appreciate visual aids in lengthy CLI snippets. Give me a piece of code that is not syntax highlighted, and my reading speed will significantly drop.

And even though the Network OS CLI snippets do not contain code per-se, they have markers (such as a current command, IP addresses, up/down statuses, etc.) that when highlighted, contribute to the clarity of the provided snippet.

So during a lazy first Thursday of 2023 I finally made myself looking into it and created the srlinux-pygments - a Pygments lexer to highlight SR Linux CLI snippets.

--{ * candidate shared default }--[ network-instance black ]--
A:leaf1# info static-routes
        static-routes {
            route 192.168.18.0/24 {
                admin-state enable
                metric 1
                preference 5
                next-hop-group static-ipv4-grp
            }
            route 2001:1::192:168:18:0/64 {
                admin-state enable
                metric 1
                preference 6
                next-hop-group static-ipv6-grp
            }
        }

--{ * candidate shared default }--[ network-instance black ]--
A:leaf1# info static-routes
        static-routes {
            route 192.168.18.0/24 {
                admin-state enable
                metric 1
                preference 5
                next-hop-group static-ipv4-grp
            }
            route 2001:1::192:168:18:0/64 {
                admin-state enable
                metric 1
                preference 6
                next-hop-group static-ipv6-grp
            }
        }

Jump under the cut to know how to create a custom syntax highlighter based on SR Linux CLI example and integrate it with mkdocs-material doc theme.

Using Ansible with SR Linux's JSON-RPC Interface

A few days after we fleshed out our JSON-RPC Basics tutorial, and we are releasing another one. While basics tutorial is essential to read to understand how the interface works, the curl utility we used in the examples there is not something you would like to automate your network with.

Quite a lot of network ops teams we've been talking to used Ansible to manage their infra, and they wanted to keep using it for network automation as well. While this is a questionable tactic, we still can give you the "fishing rod".

Please welcome - Using Ansible with SR Linux's JSON-RPC Interface tutorial, which puts our JSON-RPC interface to work under Ansible command through a set of task-oriented exercises.

JSON-RPC Management Interface

Nokia SR Linux Network OS architecture has been built on strong principles of model-driven APIs and interfaces. Not a single thing in SR Linux datastores can get away without having a matching YANG module describing it.

The ground-up model-driven approach allowed us to build management interfaces that don't have shortness of sight as every interface, in essence, uses the common API layer presented by the management server. One of such interfaces - JSON-RPC - that SR Linux offers has been in the shade of a cool-kid gNMI, though JSON-RPC has lots to offer.

We are glad to present you with an in-depth tutorial on SR Linux's JSON-RPC interface - JSON-RPC Basics.

In this tutorial, we explain the JSON-RPC capabilities and provide practical examples for every method this interface offers. Be it retrieval of state, model-driven configuration using JSON, or pushing CLI-styled commands - JSON-RPC has you covered.