ci/valve-infra-container-build: check that /mnt/* dirs are unmodified
This adds a check after running the ansible playbook to configure the container that /mnt/tmp and /mnt/permanent are not touched by ansible. They are mounted at runtime and so creating/writing to these directories is a bug, since any config added there by ansible when building the container would 'disappear' when they are mounted at runtime.
The check looks like this if it fails:
ERROR: directories/files should not exist, which probably means ansible created them:
/mnt/tmp
/mnt/tmp/registry
/mnt/tmp/influxdb
/mnt/tmp/influxdb/.bash_logout
/mnt/tmp/influxdb/.bash_profile
/mnt/tmp/influxdb/.bashrc
+ exit 1
Fixes #87 (closed)
Remaining commits in this series fix situations that caused the new test to fail (except for the commit that adds a comment... I snuck that one in)