Feature Request: run docker task as a different user

[JamborJan]

Problem

When executing a command inside a docker container, it is possible to specify a user. Some tasks require running with a specific user, e.g. the nextcloud fulltext search re-index job. For example:

docker exec -u www-data nextcloud php occ fulltextsearch:index

When I'm trying to add this job to docker-crontab like this to run it every night at 1:30h:

- name: nextcloud-fulltext
  command: php occ fulltextsearch:index
  comment: re-indexing nextcloud fulltext search for documents
  container: nextcloud
  schedule: '30  1 * * *'

I get an error from the nextcloud container that I have to run the command as user www-data.

Proposed solution

It would be great to be able to specify a user in config.yml which will be translated into a docker run -u user command in the generated *.sh file for the cronjob. I think this would solve this issue.

Workaround

Right now I'm doing a workaround by scheduling a docker command running within the docker-crontab container which then executes a command within the nextcloud container.

- name: nextcloud-fulltext
  command: docker exec -u www-data nextcloud php occ fulltextsearch:index
  comment: re-indexing nextcloud fulltext search for documents
  container: crontab
  schedule: '30  1 * * *'

This generates a docker exec command which then runs again a docker exec command but with specified user.

[Kelivan]

Use "dockerargs": "-u username".
As a result, the script will look like this:

for CONTAINER_NAME in $CONTAINERS; do
    docker exec -u username ${CONTAINER_NAME} command
done

[JamborJan]

Hey @Kelivan,

Thanks for your help, that did of course work. Just in case someone stumbles over this issue, this is the complete working example:

- name: nextcloud-fulltext
  dockerargs: '-u 1000'
  command: php occ fulltextsearch:index
  comment: re-indexing nextcloud fulltext search for documents
  container: nextcloud
  schedule: '30  2 * * *'

This creates this script:

echo "Start Cronjob **nextcloud-fulltext** re-indexing nextcloud fulltext search for documents"
docker exec -u 1000 nextcloud php occ fulltextsearch:index
echo "End Cronjob **nextcloud-fulltext** re-indexing nextcloud fulltext search for documents"

[JamborJan]

I allowed myself to add an example to the config examples. I hope that helps.