Containerlab re-deploy falls into amnesia with faulty template

[bebehei]

I had been visiting the DENOG containerlab workshop, which was very nice to get a grasp of containerlab. I have now successfully built sonic VM and Ubuntu VM images, which boot up.

In the workshop, it was told there is containerlab deploy --reconfigure available. I understood it like terraform apply or docker compose up -d, so that it syncs the state from current configuration with the running state.

But whenever I execute it with a faulty template, it spectacularly fails and removes the clab-<projectname> folder bringing containerlab into a state of total amnesia.

bene@containerlab:~/pop-fra1$ vim sonic-srlinux.clab.yml 
bene@containerlab:~/pop-fra1$ ls
bond.sh  clab-pop-fra1  file.txt  notes.txt  sonic-srlinux.clab.yml  startup-config.json  startup-configs

As you can see, the clab-pop-fra1 is still there.

bene@containerlab:~/pop-fra1$ sudo containerlab deploy --reconfigure
INFO[0000] Containerlab v0.60.1 started                 
INFO[0000] Parsing & checking topology file: sonic-srlinux.clab.yml 
Error: unable to find node tor1-1.fra1.3q.inet
bene@containerlab:~/pop-fra1$ vim sonic-srlinux.clab.yml 
bene@containerlab:~/pop-fra1$ sudo containerlab deploy --reconfigure
INFO[0000] Containerlab v0.60.1 started                 
INFO[0000] Parsing & checking topology file: sonic-srlinux.clab.yml 
Error: unable to find node tor1.rack2.fra1.3q.inet
bene@containerlab:~/pop-fra1$ vim sonic-srlinux.clab.yml 
bene@containerlab:~/pop-fra1$ sudo containerlab deploy --reconfigure
INFO[0000] Containerlab v0.60.1 started                 
INFO[0000] Parsing & checking topology file: sonic-srlinux.clab.yml 
INFO[0000] Removing /home/bene/pop-fra1/clab-pop-fra1 directory... 
Error: the 'pop-fra1' lab has already been deployed. Destroy the lab before deploying a lab with the same name
bene@containerlab:~/pop-fra1$ sudo containerlab destroy
INFO[0000] Parsing & checking topology file: sonic-srlinux.clab.yml 
INFO[0000] Parsing & checking topology file: sonic-srlinux.clab.yml 
Error: folder /home/bene/pop-fra1/clab-pop-fra1 does not exist or is not accessible
bene@containerlab:~/pop-fra1$ ls
bond.sh  file.txt  notes.txt  sonic-srlinux.clab.yml  startup-config.json  startup-configs

The state folder clab-pop-fra1 is now totally missing.

However, the containers are still there.

bene@containerlab:~/pop-fra1$ docker ps -a
CONTAINER ID   IMAGE                                      COMMAND                  CREATED             STATUS                       PORTS                                 NAMES
2846ae919ad2   vrnetlab/canonical_ubuntu:noble            "/launch.py --userna…"   About an hour ago   Up About an hour (healthy)   22/tcp, 5000/tcp, 10000-10099/tcp     clab-pop-fra1-server
ec140082e831   vrnetlab/sonic_sonic-vs:sonics-vs-202405   "/launch.py --userna…"   About an hour ago   Up About an hour (healthy)   22/tcp, 443/tcp, 5000/tcp, 8080/tcp   clab-pop-fra1-tor1-1.fra1.3q.inet
67a755ef8c49   vrnetlab/sonic_sonic-vs:sonics-vs-202405   "/launch.py --userna…"   About an hour ago   Up About an hour (healthy)   22/tcp, 443/tcp, 5000/tcp, 8080/tcp   clab-pop-fra1-tor2-1.fra1.3q.inet
bene@containerlab:~/pop-fra1$

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While preparing and reading the logs, I also see that the second deploy --reconfigure removes the folder:

INFO[0000] Removing /home/bene/pop-fra1/clab-pop-fra1 directory...

Why does containerlab do this? I'd expect a redeploy fail, but not fall into full amnesia.

[hellt]

reconfigure simply removes the old state (clab-<lab-name> dir on disk) and attempts to create a new lab from scratch

it is a combination of destroy --cleanup with a subsequent deploy.

There is no sync of any state