Quickstart

Inmanta is intended to manage complex infrastructures, often in the cloud or other virtualized environments. In this guide we start simple and manage a 3-node CLOS network with a spine and two leaf switches. First we install containerlab and then configure SR Linux containers using Inmanta open source orchestrator and gNMI.

1. First, we use Containerlab to spin-up Inmanta server and its PostgreSQL database, then three SR Linux containers, connected in a CLOS like topology

2. After that, we configure IP addresses and OSPF on them using Inmanta.

Note

This guide is meant to quickly set up an Inmanta LAB environment to experiment with. It is not recommended to run this setup in production, as it might lead to instabilities in the long term.

Prerequisites

Python version 3.9, Docker, Containerlab and Inmanta need to be installed on your machine and our SR Linux repository has to be cloned in order to proceed. Please make sure to follow the links below to that end.

1. Install Docker.

2. Install Containerlab.

3. Prepare a development environment by creating a python virtual environment and installing Inmanta:

   mkdir -p ~/.virtualenvs
   python3 -m venv ~/.virtualenvs/srlinux
   source ~/.virtualenvs/srlinux/bin/activate
   pip install inmanta
   

4. Clone the SR Linux examples repository:

   git clone https://github.com/inmanta/examples.git
   

5. Change directory to SR Linux examples:

   cd examples/Networking/SR\ Linux/
   

This folder contains a project.yml, which looks like this:

name: SR Linux Examples
description: Provides examples for the SR Linux module
author: Inmanta
author_email: code@inmanta.com
license: ASL 2.0
copyright: 2022 Inmanta
modulepath: libs
downloadpath: libs
repo:
- type: package
    url: https://packages.inmanta.com/public/quickstart/python/simple/
install_mode: release
requires:

• The modulepath setting defines that modules will be stored in libs directory.

• The repo setting points to one or more Git repositories containing Inmanta modules.

• The requires setting is used to pin versions of modules, otherwise the latest version is used.

1. Install the required modules inside the SR Linux folder:

   inmanta project install
   

   Note

   should you face any errors at this stage, please contact us.

In the next sections we will showcase how to set up and configure SR Linux devices.

Setting up the LAB

Go to the SR Linux folder and then containerlab to spin-up the containers:

cd examples/Networking/SR\ Linux/containerlab
sudo docker pull ghcr.io/nokia/srlinux:latest
sudo clab deploy -t topology.yml

Containerlab will spin-up:

1. an Inmanta server

2. a PostgreSQL Database server

3. Three SR Linux network operating systems.

Depending on your system’s horsepower, give them a few seconds/minutes to fully boot-up.

Connecting to the containers

At this stage, you should be able to view the Web Console by navigating to:

http://172.30.0.3:8888/console

To get an interactive shell to the Inmanta server:

docker exec -it clab-srlinux-inmanta-server /bin/bash

In order to connect to SR Linux containers, there are two options:

1. Using Docker:

docker exec -it clab-srlinux-spine sr_cli
# or
docker exec -it clab-srlinux-leaf1 sr_cli
# or
docker exec -it clab-srlinux-leaf2 sr_cli

2. Using SSH (username admin and password NokiaSrl1!):

ssh admin@clab-srlinux-spine
ssh admin@clab-srlinux-leaf1
ssh admin@clab-srlinux-leaf2

The output should look something like this:

Welcome to the srlinux CLI.
Type 'help' (and press <ENTER>) if you need any help using this.


--{ running }--[  ]--
A:spine#

Optionally, you can enter the configuration mode by typing:

enter candidate

Exit the session by typing:

quit

Now that we have the needed containers, we will need to go up a directory where the project files exist:

cd ..

Note

The rest of the this guide assumes commands are executed from the root path of the SR Linux folder, unless noted otherwise.

Create an Inmanta project and an environment

A project is a collection of related environments. (e.g. development, testing, production, qa,…). We need to have an environment to manage our infrastructure. An environment is a collection of resources, such as servers, switches, routers, etc.

There are two ways to create a project and an environment:

1. Using Inmanta CLI (recommended):

# Create a project called test
inmanta-cli --host 172.30.0.3 project create -n test
# Create an environment called SR_Linux
inmanta-cli --host 172.30.0.3 environment create -p test -n SR_Linux --save

The first option, inmanta-cli, will automatically create a .inmanta file that contains the required information about the server and environment ID. The compiler uses this file to find the server and to export to the right environment.

2. Using the Web Console: Connect to the Inmanta container http://172.30.0.3:8888/console, click on the Create new environment button, provide a name for the project and the environment then click submit.

If you have chosen the second option, the Web Console, you need to copy the environment ID for later use, either:

• from the URL, e.g. ec05d6d9-25a4-4141-a92f-38e24a12b721 from the http://172.30.0.3:8888/console/desiredstate?env=ec05d6d9-25a4-4141-a92f-38e24a12b721.

• or by clicking on the Settings pane, then in the Environment tab, scroll down all the way to the bottom of the page and copy the environment ID.

Configuring SR Linux

There are a bunch of examples present inside the SR Linux folder of the examples repository that you have cloned in the previous step, setting up the lab.

In this guide, we will showcase two examples on a small CLOS topology to get you started:

1. interface configuration.

2. OSPF configuration.

It could be useful to know that Inmanta uses the gNMI protocol to interface with SR Linux devices.

Note

In order to make sure that everything is working correctly, run inmanta compile. This will ensure that the modules are in place and the configuration is valid. If you face any errors at this stage, please contact us.

SR Linux interface configuration

The interfaces.cf file contains the required configuration model to set IP addresses on point-to-point interfaces between the spine, leaf1 and leaf2 devices according to the aforementioned topology.

Let’s have a look at the partial configuration model:

import srlinux
import srlinux::interface as srinterface
import srlinux::interface::subinterface as srsubinterface
import srlinux::interface::subinterface::ipv4 as sripv4
import yang



######## Leaf 1 ########

leaf1 = srlinux::GnmiDevice(
    auto_agent = true,
    name = "leaf1",
    mgmt_ip = "172.30.0.210",
    yang_credentials = yang::Credentials(
        username = "admin",
        password = "NokiaSrl1!"
    )
)

leaf1_eth1 = srlinux::Interface(
    device = leaf1,
    name = "ethernet-1/1",
    mtu = 9000,
    subinterface = [leaf1_eth1_subint]
)

leaf1_eth1_subint = srinterface::Subinterface(
    parent_interface = leaf1_eth1,
    x_index = 0,
    ipv4 = leaf1_eth1_subint_address
)

leaf1_eth1_subint_address = srsubinterface::Ipv4(
    parent_subinterface = leaf1_eth1_subint,
    address = sripv4::Address(
        parent_ipv4 = leaf1_eth1_subint_address,
        ip_prefix = "10.10.11.2/30"
    )
)

• Lines 1-5 import the required modules/packages.

• Lines 11-19 instantiate the device; GnmiDevice object and set the required parameters.

• Lines 21-26 instantiate the Interface object by selecting the parent interface, ethernet-1/1 and setting the MTU to 9000.

• Lines 28-32 instantiate the Subinterface object, link to the parent interface object, set an index and link to the child Ipv4 object.

• Lines 34-40 instantiate the Ipv4 object, link to the parent Subinterface object, set the IP address and prefix.

The rest of the configuration model follows the same method for leaf2 and spine devices, with the only difference being the spine having two interfaces, subinterfaces and IP addresses.

Now, we can deploy the model by referring to Deploy the configuration model section.

SR Linux OSPF configuration

The ospf.cf file contains the required configuration model to first set IP addresses on point-to-point interfaces between the spine, leaf1 and leaf2 devices according to the aforementioned topology and then configure OSPF between them.

This model build on top of the interfaces model that was discussed in SR Linux interface configuration. It first imports the required packages, then configures interfaces on all the devices and after that, adds the required configuration model for OSPF.

Let’s have a look at the partial configuration model:

import srlinux
import srlinux::interface as srinterface
import srlinux::interface::subinterface as srsubinterface
import srlinux::interface::subinterface::ipv4 as sripv4
import srlinux::network_instance as srnetinstance
import srlinux::network_instance::protocols as srprotocols
import srlinux::network_instance::protocols::ospf as srospf
import srlinux::network_instance::protocols::ospf::instance as srospfinstance
import srlinux::network_instance::protocols::ospf::instance::area as srospfarea
import yang



######## Leaf 1 ########

leaf1 = srlinux::GnmiDevice(
    auto_agent = true,
    name = "leaf1",
    mgmt_ip = "172.30.0.210",
    yang_credentials = yang::Credentials(
        username = "admin",
        password = "admin"
    )
)

# |interface configuration| #

leaf1_eth1 = srlinux::Interface(
    device = leaf1,
    name = "ethernet-1/1",
    mtu = 9000,
    subinterface = [leaf1_eth1_subint]
)

leaf1_eth1_subint = srinterface::Subinterface(
    parent_interface = leaf1_eth1,
    x_index = 0,
    ipv4 = leaf1_eth1_subint_address
)

leaf1_eth1_subint_address = srsubinterface::Ipv4(
    parent_subinterface = leaf1_eth1_subint,
    address = sripv4::Address(
        parent_ipv4 = leaf1_eth1_subint_address,
        ip_prefix = "10.10.11.2/30"
    )
)

# |network instance| #

leaf1_net_instance = srlinux::NetworkInstance(
    device = leaf1,
    name = "default",
)

leaf1_net_instance_int1 = srnetinstance::Interface(
    parent_network_instance = leaf1_net_instance,
    name = "ethernet-1/1.0"
)

# |OSPF| #

leaf1_protocols = srnetinstance::Protocols(
    parent_network_instance = leaf1_net_instance,
    ospf = leaf1_ospf
)

leaf1_ospf_instance = srospf::Instance(
        parent_ospf = leaf1_ospf,
        name = "1",
        router_id = "10.20.30.210",
        admin_state = "enable",
        version = "ospf-v2"
)

leaf1_ospf = srprotocols::Ospf(
    parent_protocols = leaf1_protocols,
    instance = leaf1_ospf_instance
)

leaf1_ospf_area = srospfinstance::Area(
    parent_instance = leaf1_ospf_instance,
    area_id = "0.0.0.0",
)

leaf1_ospf_int1 = srospfarea::Interface(
    parent_area = leaf1_ospf_area,
    interface_name = "ethernet-1/1.0",
)

• Lines 1-10 import the required modules/packages.

• Lines 16-24 instantiate the device; GnmiDevice object and set the required parameters.

• Lines 28-33 instantiate the Interface object by selecting the parent interface, ethernet-1/1 and setting the MTU to 9000.

• Lines 35-39 instantiate the Subinterface object, link to the parent interface object, set an index and link to the child Ipv4 object.

• Lines 41-47 instantiate the Ipv4 object, link to the parent Subinterface object, set the IP address and prefix.

• Lines 51-54 instantiate NetworkInstance object, set the name to default.

• Lines 56-59 instantiate a network instance Interface object, link to the default network instance object and use ethernet-1/1.0 as the interface.

• Lines 63-66 instantiate the Protocols object, link to the default network instance object and link to the OSPF object which we will create shortly.

• Lines 68-74 instantiate an OSPF instance and OSPF Instance, link to the OSPF instance, provide a name, router ID, admin state and version.

• Lines 76-79 instantiate an OSPF object, link to the Protocols object and link to the OSPF instance.

• Lines 81-84 instantiate an Area object, link to the OSPF instance and provide the area ID.

• Lines 86-89 instantiate an area Interface object, link to the OSPF area object and activates the OSPF on ethernet-1/1.0 interface.

The rest of the configuration model follows the same method for leaf2 and spine devices, with the only difference being the spine having two interfaces, subinterfaces and IP addresses and OSPF interface configuration.

Now, we can deploy the model by referring to Deploy the configuration model section.

Deploy the configuration model

To deploy the project, we must first register it with the management server by creating a project and an environment. We have covered this earlier at Create an Inmanta project and an environment section.

Export the interfaces configuration model to the Inmanta server:

inmanta -vvv export -f interfaces.cf
# or
inmanta -vvv export -f interfaces.cf -d

Export the OSPF configuration model to the Inmanta server:

inmanta -vvv export -f ospf.cf
# or
inmanta -vvv export -f ospf.cf -d

Note

The -vvv option sets the output of the compiler to very verbose. The -d option instructs the server to immediately start the deploy.

When the model is sent to the server, it will start deploying the configuration. To track progress, you can go to the web-console, select the test project and then the SR_Linux environment and click on Resources tab on the left pane to view the progress.

When the deployment is complete, you can verify the configuration using the commands provided in Verifying the configuration section.

If the deployment fails for some reason, consult the troubleshooting page to investigate the root cause of the issue.

Verifying the configuration

After a successful deployment, you can connect to SR Linux devices and verify the configuration.

Pick all or any of the devices you like, connect to them as discussed in Connecting to the containers section and check the configuration:

show interface ethernet-1/1.0
show network-instance default protocols ospf neighbor
show network-instance default route-table ipv4-unicast summary
info flat network-instance default

Resetting the LAB environment

To fully clean up or reset the LAB, go to the containerlab folder and run the following commands:

cd containerlab
sudo clab destroy -t topology.yml

This will give you a clean LAB the next time you run:

sudo clab deploy -t topology.yml --reconfigure

Reusing existing modules

We host modules to set up and manage many systems on our Github. These are available under https://github.com/inmanta/.

When you use an import statement in your model, Inmanta downloads these modules and their dependencies when you run inmanta project install. V2 modules (See V2 module format) need to be declared as Python dependencies in addition to using them in an import statement. Some of our public modules are hosted in the v2 format on https://pypi.org/.

Update the configuration model

The provided configuration models can be easily modified to reflect your desired configuration. Be it a change in IP addresses or adding new devices to the model. All you need to do is to create a new or modify the existing configuration model, say interfaces.cf to introduce your desired changes.

For instance, let’s change the IP address of interface ethernet-1/1.0 to 100.0.0.1/24 in the interfaces.cf configuration file:

import srlinux
import srlinux::interface as srinterface
import srlinux::interface::subinterface as srsubinterface
import srlinux::interface::subinterface::ipv4 as sripv4
import yang



######## Leaf 1 ########

leaf1 = srlinux::GnmiDevice(
    auto_agent = true,
    name = "leaf1",
    mgmt_ip = "172.30.0.210",
    yang_credentials = yang::Credentials(
        username = "admin",
        password = "admin"
    )
)

leaf1_eth1 = srlinux::Interface(
    device = leaf1,
    name = "ethernet-1/1",
    mtu = 9000,
    subinterface = [leaf1_eth1_subint]
)

leaf1_eth1_subint = srinterface::Subinterface(
    parent_interface = leaf1_eth1,
    x_index = 0,
    ipv4 = leaf1_eth1_subint_address
)

leaf1_eth1_subint_address = srsubinterface::Ipv4(
    parent_subinterface = leaf1_eth1_subint,
    address = sripv4::Address(
        parent_ipv4 = leaf1_eth1_subint_address,
        ip_prefix = "100.0.0.1/24"
    )
)

Additionally, you can add more SR Linux devices to the topology.yml file and explore the possible combinations.

Modify or Create your own modules

Inmanta enables developers of a configuration model to make it modular and reusable. We have made some videos that can walk you through the entire process in a short time.

Please check our YouTube playlist to get started.

Module layout

A configuration module requires a specific layout:

• The name of the module is determined by the top-level directory. Within this module directory, a module.yml file has to be specified.

• The only mandatory subdirectory is the model directory containing a file called _init.cf. What is defined in the _init.cf file is available in the namespace linked with the name of the module. Other files in the model directory create subnamespaces.

• The files directory contains files that are deployed verbatim to managed machines.

• The templates directory contains templates that use parameters from the configuration model to generate configuration files.

• The plugins directory contains Python files that are loaded by the platform and can extend it using the Inmanta API.

module
|
|__ module.yml
|
|__ files
|    |__ file1.txt
|
|__ model
|    |__ _init.cf
|    |__ services.cf
|
|__ plugins
|    |__ functions.py
|
|__ templates
     |__ conf_file.conf.tmpl

Custom modules should be placed in the libs directory of the project.

Next steps

Model developer documentation