# Adding New Virtualization Provider for an Existing Device

If you want to run a network device on a virtualization provider that is not yet supported by *netlab* (example: Cisco IOS packaged as a vrnetlab container), you came to the right place.

Here's what you have to do:

* Build a Vagrant box from whatever image your vendor supplies. It's not as hard as it sounds, there are [tons of recipes on codingpackets.com](https://codingpackets.com/blog/tag/#vagrant). If you want to build a container to use with *containerlab*, please refer to [their documentation](https://containerlab.srlinux.dev/).
* Document the process in a blog post or GitHub gist.
* Modify the device parameter file `netsim/devices/<device>.yml`
* Update [Supported Platforms](../platforms.md) and box building documentation ([libvirt](../labs/libvirt.md#building-your-own-boxes), [VirtualBox](../labs/virtualbox.md#creating-vagrant-boxes))
* [Submit a PR](guidelines.md)
* Enjoy!

## Adding a Box Name to Topology Defaults

* Find your device settings within `netsim/devices` directory
* Add a new key *provider* key for the target device (valid keys are `libvirt`, `virtualbox` or `clab`). Add **image** parameter under the *provider* key. Its value is the expected Vagrant box name or Docker container.

Example (`routeros.yml`):

```
interface_name: ether%d
virtualbox:
  image: mikrotik/chr
```

Recommended:

* Use standard Docker Hub container names (which can include the version number in *tag* field)
* If you need a version number for a Vagrant image downloaded from Vagrant Cloud, use *user/image:version* format (example: `CumulusCommunity/cumulus-vx:4.3.0`)

## Changing Provider-Specific Device Settings

You can change default device settings for a specific virtualization provider within the device parameter file.

There are four types of settings you can change:

**Default settings** (easy) -- **_provider_.something** settings are merged with the device settings. 

**Example:** Change management interface name and container image on Arista cEOS:

```
mgmt_if: Management1
clab:
  mgmt_if: Management0devices:
  image: ceos:4.31.2F
```

**Ansible group variables** (easy) -- values specified in **group_vars** section of device-and-provider-specific settings overwrite the device defaults. 

Example: Change Ansible connection for a Cumulus VX container:

```
interface_name: swp{ifindex}
libvirt:
  image: CumulusCommunity/cumulus-vx:4.4.0
virtualbox:
  image: CumulusCommunity/cumulus-vx:4.3.0
group_vars:
  ansible_user: vagrant
  ansible_ssh_pass: vagrant
  ansible_network_os: cumulus
  ansible_connection: paramiko
clab:
  image: networkop/cx:4.4.0
  group_vars:
    ansible_connection: docker
    ansible_user: root
```

**Node parameters** (manageable)-- the **node** dictionary within provider-specific device settings is copied into node data under _provider_ key.

Example: *containerlab* needs a *device kind* setting in its configuration file. The configuration file template uses **clab.kind** value within node data to set that parameter, so we need a mechanism to set **clab.kind** value for every node. 

Solution: use **node** dictionary within **clab** device parameters:

```
interface_name: swp{ifindex}
loopback_interface_name: "lo{ifindex}"
mgmt_if: eth0
libvirt:
  image: CumulusCommunity/cumulus-vx:4.4.0
clab:
  node:
    kind: cvx
    runtime: docker
  image: networkop/cx:4.4.0
```

**Interface names** (mind-boggling). Interface names used by the network device might differ from the interface names used by virtualization provider (example: Arista cEOS on *containerlab*).

Solution: set **interface.name** in provider-specific device settings. Whenever those settings include **interface.name** value, the link interface data and node interfaces data includes **_provider_.name** value for every interface. That value can then be used in configuration templates.

**Example:** Arista cEOS containerlab settings

```
interface_name: Ethernet{ifindex}
description: Arista vEOS
mgmt_if: Management1
loopback_interface_name: Loopback{ifindex}
libvirt:
  image: arista/veos
virtualbox:
  image: arista/veos
clab:
  image: ceos:4.31.2F
  interface:
    name: et{ifindex}
```

**Example**: Part of containerlab configuration template

```
...
  links:
{% for l in links %}
  - endpoints:
{%   for n in nodes.values() %}
{%     for nl in n.interfaces if nl.linkindex == l.linkindex %}
{%       set clab = nl.clab|default({}) %}
    - "{{ n.name }}:{{ clab.name|default(nl.ifname) }}"
{%     endfor %}
{%   endfor %}
{% endfor %}
```