How to configure Nomad to reference CNI plugins location?

Nomad
1

I’m having some trouble getting Nomad to reference the CNI plugins from the Debian 12 packages. The Debian 12 packages drop the CNI plugins in /usr/lib/cni:

$ dpkg -L containernetworking-plugins | grep loopback
/usr/lib/cni/loopback

and so I have a plugin config directive in /etc/nomad.d/nomad.hcl:

plugin "cni" {
  directory = "/usr/lib/cni"
}

however after a restart I’m getting log messages like so:

... msg="failed to setup alloc: pre-run hook \"network\" failed: failed to configure networking for alloc: failed to configure network: plugin type=\"loopback\" failed (add): failed to find plugin \"loopback\" in path [/opt/cni/bin]" failed=true

which seems to suggest that Nomad is still looking for CNI in /opt/cni/bin.

2

fwiw, I was able to get this working via:

mkdir -p /opt/cni && \
  cd /opt/cni && \
  ln -s /usr/lib/cni bin

but that’s sort of a cheap hack.

3

Hi @niftyjennins,

You can use the client.cni_path configuration parameter to specify where the CNI plugins can be found along with the client.cni_config_dir to specify the path to any CNI configuration files.

Your configuration could therefore look like:

client {
  cni_path = "/usr/lib/cni/"
}

Thanks,
jrasell and the Nomad team

1 Like
4

Thanks. FWIW, here is the working config for Debian 12 with the containernetworking-plugins package installed:

client {
  cni_path = "/usr/lib/cni"
  cni_config_dir = "/etc/nomad.d/cni_config"
}
1 Like