Trouble scripting container launch

Incus
1

Has anyone had luck making a provisioning script that pulls hostname and IP address from a csv file and looping through the file to launch containers?

Here is my rudimentary script trying to do just that, my csv file is “host-list” formatted as such

c1,192.168.0.222
c2,192.168.0.221
c3,192.168.0.220
c4,192.168.0.219
.......

My bash script:

#! /bin/bash -vx
while IFS=',' read -r name_c1 ip_c2
do
  file=v1-$ip_c2.yaml
  # cat $file
   echo "File" $file
incus launch images:debian/12/cloud "$name_c1" -p prod-mgt --config=cloud-init.network-config="$(cat $file)"

done <  host-list

Gives me this error:
Error: yaml: unmarshal errors:
line 1: cannot unmarshal !!str c2,192.... into api.InstancePut

Seems to struggle with the --config=cloud-init.network-config=“$(cat $file)” section, yet it does render and expand $file. Have used shellcheck to check syntax, but it finds no errors.

Thought I would ask, as others may do the same thing for rapid container deployment.

Thank you

2

incus launch reads from stdin by default so that’s likely the issue here.
Try to do incus launch ... < /dev/null to force stdin to be closed to avoid this issue.

3

Ah ok. Thanks for that info Stéphane.

This is a little cleaner:

#! /bin/bash
while IFS=',' read -r name_c1 ip_c2
do
    file=v1-$ip_c2.yaml

    cat >> "$file" << EOF
network:
  version: 1
  config:
    - type: physical
      name: eth0
      subnets:
        - type: static
          address: $ip_c2/24
          gateway: 192.168.0.1
          dns_nameservers:
            - 192.168.50.50
            - 192.168.0.1
          dns_search:
            - example.com
EOF
# provision containers
incus launch images:debian/12/cloud "$name_c1" -p prod-mgt --config=cloud-init.network-config="$(cat $file)" < /dev/null
done <  host-list

rm v1-*
exit

Edited…

4

I prefer to avoid the temporary files by putting the config inline: example here. Care is needed if you need inner double quotes, or dollar literals.

Another way might be something bash-specific, like:

( incus launch ... -c user.network-config="$(cat <&3)" -c user.user-data="$(cat <&4)" ) 3<<EOS1 4<<EOS2
version: 2
foo...
EOS1
#cloud-config
bar...
EOS2
1 Like
5

Thanks Brian! I was thinking I could do something like this to save on disk I/O, just needed some examples. Just what I was looking for.

Here is what is working for me:

incus launch images:$image_c4 "$name_c1" -p $prof_c3 -c cloud-init.network-config="version: 1
config:
  - type: physical
    name: eth0
    subnets:
      - type: static
        address: $ip_c2/24
        gateway: 192.168.0.1
     - type: nameserver
       address:
         - 192.168.0.1
         - 192.168.50.50
       search:
         - example.lan
" < /dev/null

Tested on several distros with no issues.

Thanks again for all the input!