pg_upgrade.yml: Add ‘string’ filter for postgresql version variables

[ruslanloman]

Description

Ansible pg_upgrade.yml pre_check is failed when postgresql_version is int, because
regex_replace ansible filter expects a string or pattern.

Initially postgresql_version was a string, but changed in this PR to int

ansible-playbook pg_upgrade.yml -e "pg_old_version=15 pg_new_version=16"

TASK [upgrade : Make sure that the old and new data and config directories do not match] ***********************************************
fatal: [192.168.40.135]: FAILED! => {"msg": "The conditional check '(pg_old_datadir == pg_new_datadir) or (pg_old_confdir == pg_new_confdir)' failed. The error was: An unhandled exception occurred while templating '{{ postgresql_data_dir | regex_replace('(/$)', '') | regex_replace(postgresql_version, pg_old_version) }}'. Error was a <class 'ansible.errors.AnsibleError'>, original message: Unexpected templating type error occurred on ({{ postgresql_data_dir | regex_replace('(/$)', '') | regex_replace(postgresql_version, pg_old_version) }}): first argument must be string or compiled pattern. first argument must be string or compiled pattern\n\nThe error appears to be in '/home/loman/postgresql_cluster/automation/roles/upgrade/tasks/pre_checks.yml': line 14, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n# Stop, if the directories of the old and new versions are the same\n- name: \"Make sure that the old and new data and config directories do not match\"\n  ^ here\n"}

[vitabaks]

Thanks! @ruslanloman

It is better to add a string filter to the appropriate parts of the code than to require users to specify the version as a string. This will be a more flexible and more reliable option.

example

{{ postgresql_data_dir | string | regex_replace('(/$)', '') | regex_replace(postgresql_version | string, pg_old_version | string) }}

To avoid this error, we need to make sure that all arguments passed to regex_replace are strings. To do this, we can use the string filter, which explicitly converts the value to a string.

[vitabaks]

@ruslanloman Are you planning a new PR or can I do it myself?

[ruslanloman]

Hi @vitabaks,

Thank you for your comment. Yes, I'm preparing an update for PR. I agree about this part "require users to specify the version as a string". I found out that we can use jinja2 replace filter instead of ansible regex_replace filter. I've updated code, but checking that deployment and upgrade works as expected.

[ruslanloman]

@vitabaks Updated. My local deployment/upgrade test passed.

[vitabaks]

recommended to use a string filter to avoid possible errors, example:

replace(postgresql_version | string, pg_old_version | string)

[ruslanloman]

recommended to use a string filter to avoid possible errors, example:

replace(postgresql_version | string, pg_old_version | string)

Updated. Thanks