How to specify first container in rancher exec

Archive Rancher 1.x
1

In CI I want to run some script inside deployed container. It works only if there is only one container in the service, if more it asks what container to use. Is there a way how to run it in first available container and not ask?

This is log from GitLab CI:

$ rancher exec project-name/web /migrate.sh[0;m
Containers:
[1] helpdesk-master-web-1 (10.42.250.82)
[2] helpdesk-master-web-1 (10.42.27.90)
Select: [1] helpdesk-master-web-1 (10.42.250.82)
[2] helpdesk-master-web-1 (10.42.27.90)
Select: [1] helpdesk-master-web-1 (10.42.250.82)
[2] helpdesk-master-web-1 (10.42.27.90)
Select: [1] helpdesk-master-web-1 (10.42.250.82)
…
2

Or is there some other elegant way how to remotely execute script inside a container on new version deploy? It does not necessary to run it in the same container what has been just deployed.

What is best practice for DB upgrade scripts?

3

This is what I have done.
Run rancher command to get the container ID of one container. The xxx-1 has always been available for me.
export CONTAINER_ID=rancher ps -c|grep -i helpdesk-master-web-1|cut -f 1 -d' '

Run the exec command with the container ID from the previous command. You can re-direct you output as needed.
rancher exec -i $CONTAINER_ID sh -c “/migrate.sh 2>&1 |tee /dev/console”