Today, I’ll focus on another feature of the new files plugin – you can use it to embed any (hopefully small) file in a lab topology (configlets are just a special case in which the plugin creates the relative file path from the configlets dictionary data).

You could use this functionality to include configuration files for Linux containers, custom reports, or even plugins in the lab topology, and share a complete solution as a single file that can be downloaded from a GitHub repository.

To use this functionality, you have to

• Add the files plugin to the lab topology plugin list
• Add the files dictionary (or list) to the lab topology specifying file paths and their contents.

The files plugin creates the specified files during the netlab create or netlab up process. The netlab down command removes them when used it is with the --cleanup flag.

I use the files plugin to create a bash script that can be used to create graphs in the sample physical topology, BGP, IS-IS and VLAN graphs lab topologies. For example, you could execute…

netlab create https://github.com/ipspace/netlab/blob/master/tests/platform-integration/graph/isis.yml

… in an empty directory to:

• Download the sample IS-IS topology from GitHub
• Transform the lab topology into a snapshot file
• Create the make.sh file which can then be executed with bash make.sh to create the sample IS-IS graphs.

Want another example? How about using the files dictionary to create a custom report? Let’s keep it simple and create a report that will include device type and image for all nodes in the current lab topology:

files:
  reports/node-info.j2: |
    {{ "%-16s %-10s %s"|format('name','device','image') }}
    {{ "=" * 80 }}
    {% for name,data in nodes.items() %}
    {{ "%-16s %-10s %s"|format(name,data.device,data.box)}}
    {% endfor %}

With the above snippet in your topology file, you could use netlab report node-info after starting the lab with netlab up to get a simple report listing nodes, device types, and device images, for example:

% netlab report node-info
name             device     image
================================================================================
r1               iosv       cisco/iosv
r2               cumulus    CumulusCommunity/cumulus-vx:4.4.5
srv              eos        arista/veos

Finally, when you find an interesting use case for this functionality, do let me know (you could leave a comment or send me an email). I always love to hear how you’re using netlab. Thank you!