gitlab-ci: remote shell execution with variable expansion - bash

Question

Within a gitlab-ci job, I want to create a directory (on a remote server) with the job id and perform some actions more or less as follows:
- ssh user#server mkdir -p /user/$CI_JOB_ID
- ssh user#server <perform_some_action_that_creates_several_zip_files>
- LAST_MODIFIED_FILE=$(ssh user#server bash -c 'find /user/$CI_JOB_ID -iname "*.zip" | tail -n 1 | xargs readlink -f')
The directory does get created and the action that creates several zips works out.
However, the last command that I use for getting the last modified/created .zip does not work, because $CI_JOB_ID does not seem to get expanded.
Any suggestions?

Answer 1

This issue is due to your ssh call. The way you do it now, you are mixing contexts :
ssh user#server bash -c 'find /user/$CI_JOB_ID -iname "*.zip" | tail -n 1 | xargs readlink -f'
bash -c 'my_commands' : you use simple quotes, so ssh will execute exactly the instruction my_commands. In your case, it will try to find the remote value for $CI_JOB_ID, instead of using the local one.
ssh user#server bash -c "my_commands" : withssh, the commands to execute on the remote shell are sent as a single string. Thus, if you were to run ssh with this quotation, it would try to run "bash -c find ... | tail ... | xargs ...". Here, only find is run through bash -c.
In your case, simply writing directly the following statement should do the trick :
ssh user#server "find /user/$CI_JOB_ID -iname '*.zip' | tail -n 1 | xargs readlink -f"
Otherwise, if you want to keep using the bash -c syntax, you'd have to escape the quotation so that it is propagated to the remote machine :
ssh user#server bash -c \"find /user/$CI_JOB_ID -iname '*.zip' | tail -n 1 | xargs readlink -f\"