Pmm-init doesn't skip task with waiting for a local postgres even when an external postgres is used

[ddkozyreva]

Description

Hi!

We use an external postgres and define it with the PMM_POSTGRES_ADDR and PMM_DISABLE_BUILTIN_POSTGRES envs.

However the pmm-init process cannot work correctly due to the ansible task in the initialization role:

  - name: Wait for PostgreSQL to become responsive
    wait_for:
      host: 127.0.0.1
      port: 5432
      timeout: 150

And the pmm-init cannot be completed correctly due to the failed task.

It would be great if you added a condition to the problem task like when: lookup('env','PMM_POSTGRES_ADDR') == '127.0.0.1:5432' and lookup('env','PMM_DISABLE_BUILTIN_POSTGRES') != '1'.

Expected Results

We use an external postgres and expect the pmm-init process will work correctly.

Actual Results

The pmm-init runs the task for the local postgres and waits for task to be completed.

We don't have local postgres just because it runs on a separate host.

So the task fails and the playbook fails too.

Version

3.0.0

Steps to reproduce

No response

Relevant logs

Code of Conduct

• I agree to follow Percona Community Code of Conduct

[ademidoff]

@ddkozyreva I believe this happens because you don't use the other set of variables that are necessary for Grafana to work correctly with an external database. As you can see, this part would not be executed if those GF_ environment variables are non-empty.

If that is the case, I recommend you check out the relevant section in our docs.

[ddkozyreva]

Are you talking about this condition when: lookup('env','GF_DATABASE_URL') == '' and lookup('env','GF_DATABASE_HOST') == '' and need_initialization at the end of the part:

  - name: Wait for PostgreSQL to become responsive
    wait_for:
      host: 127.0.0.1
      port: 5432
      timeout: 150

  - name: Create Grafana DB
    block:
      - name: Create grafana database in postgres
        postgresql_db:
          name: grafana
          login_user: postgres
          state: present

      - name: Create grafana user in postgres
        postgresql_user:
          db: grafana
          name: grafana
          password: grafana
          priv: 'ALL'
          expires: infinity
          login_user: postgres
          state: present
        when: not ansible_check_mode
    when: lookup('env','GF_DATABASE_URL') == '' and lookup('env','GF_DATABASE_HOST') == '' and need_initialization

?

This condition is for the block Create Grafana DB. The task with waiting for postgres goes before the block with condition and it is outside the block.

Postgres task has only one condition later - when: need_initialization or need_upgrade.

So if I need to upgrade pmm version and have an external postgres then I will face this postgres task and can't complete initialization process :(

P.S. I have GF_DATABASE_URL env, so these tasks with grafana are skipped when i add the condition into the postgres task

[ddkozyreva]

Pull Request for the problem #3667