plugin py_pkgs.py does not adhere to normal ansible variable precedence rules

[Joakim Hindersson]

Normally when overriding a variable this is done using /etc/openstack_deploy/user_variables.yml, as this follows normal ansible variable precedence rules.

This seems not to be the case for the py_pkgs plugin as it traverses the folders in it's own order and stops on first hit which will be whatever is defined in the file defaults/repo_packages/openstack_services.yml.

A temporary workaround is to fork the standard repo to make changes in default values instead of using the local overrides.

Example:
In the ocata branch of openstack-ansible we try to override the swift3 package by changing the variable swift_swift3_git_install_branch to another commit as the current one is using pike dependencies. This change is done in the user_variables.yml as would be expected by a local override.

Result:
The play runs with the default value defined in defaults/repo_packages/openstack_services.yml instead of our override in user_variables.yml.

Expected result:
The play should accept the override made in user_variables.yml.

A thought for improvement is that the script should read the folders either in reverse order and stop on first hit alternatively update the value if found in a later file instead of stopping on first hit.

Order of precedence:
3. /opt/openstack-ansible dir (lowest/default values)
2. /etc/ansible/roles
1. /etc/openstack_deploy (always used if defined)

[Jean-Philippe Evrard (jean-philippe-evrard)]

The lookup is indeed behaving different as you might expect, could you check the following documentation, please?

https://docs.openstack.org/openstack-ansible/latest/user/source-overrides/index.html#overriding-other-upstream-projects-source-code

[Jesse Pretorius (jesse-pretorius)]

The precedence is actually defined by the 'pkg_locations' [1] variable in group_vars, which is used when the lookup is executed [2].

The issue you hit actually was due to the fact that the lookup will not pickup an override unless the git_repo is also specified. JP has provided a link to the documentation which tries to clarify that.

[1] https://github.com/openstack/openstack-ansible/blob/465c74e75259d44c4a9a01d7fbada5c5818ab7e2/inventory/group_vars/repo_all.yml#L71-L74
[2] https://github.com/openstack/openstack-ansible/blob/465c74e75259d44c4a9a01d7fbada5c5818ab7e2/playbooks/repo-build.yml#L56-L62