Add event trigger resource management

[Fabianoshz]

I'm opening this as a draft in case anyone wants to give feedback or test the code.

This should allow us to manage event triggers in this provider, here's how the resource would look like:

resource "postgresql_event_trigger" "event_trigger" {
  name = "event_trigger_test"

  database = postgresql_database.database.name
  schema = postgresql_schema.schema.name

  function = postgresql_function.function.name
  on = "ddl_command_end"

  owner = "postgres"

  status = "enable"

  filter {
    variable = "TAG"
    values = [
      "CREATE TABLE",
      "ALTER TABLE",
    ]
  }
}

Closes #398

[Fabianoshz]

@cyrilgdn I've used this to add a few hundred event triggers where I work, our fork has a few more commits with some fixes of things that we found after opening the PR, I can push the fixes to this branch but it's not clear to me if you're interested in that, let me know either way.

[cyrilgdn]

Hi @Fabianoshz ,

Thanks for your work and for opening this PR,
I'm interested yes, I'm just lacking a bit of time to review it properly but will have a look as soon as possible 👍

[Fabianoshz]

Perfect, I take some time this week to push the other fixes we've added on our fork

[cyrilgdn]

Thanks again for you work, here are some comments. Basically:

• The ID used in setID needs to be based on database name / event name and not only event name
• The update function doesn't work well for some cases, I explained how to test it easily in the TestCase directly
• The Exists function can be removed
• A small bug in the read function for the owner
• and a few minor comments

let me know if you need help to fix that.

[cyrilgdn]

Does it work for enable_replica and enable_always ?
it seems to generate ALTER EVENT TRIGGER name enable_replica where the documentation says:

ALTER EVENT TRIGGER name ENABLE [ REPLICA | ALWAYS ]

[cyrilgdn]

I actually checked with your test by adding an extra step like:

            {
                Config: fmt.Sprintf(testAccPostgreSQLEventTriggerConfig, dbName, schemas[0], "enable"),
                Check: resource.ComposeTestCheckFunc(
                    testAccCheckPostgresqlEventTriggerExists("postgresql_event_trigger.event_trigger", dbName),
                ),
            },
            {
                Config: fmt.Sprintf(testAccPostgreSQLEventTriggerConfig, dbName, schemas[0], "enable_always"),
                Check: resource.ComposeTestCheckFunc(
                    testAccCheckPostgresqlEventTriggerExists("postgresql_event_trigger.event_trigger", dbName),
                ),
            },

(and changing the conf definition to take %[3]s instead of "enabled" directly)
so it tries to alter the status of the event and it indeed fails with:

Error: pq: syntax error at or near "enable_always"

Full PG logs being:

ERROR:  syntax error at or near "enable_always" at character 34
STATEMENT:  ALTER EVENT TRIGGER "event_trigger_test" enable_always

[Fabianoshz]

I've added a map to fix this

[cyrilgdn]

You don't manage the renaming of an event properly, similar to the comment on status you can test easily by updating your test case with a new step that rename it, e.g.:

    {
        Config: fmt.Sprintf(testAccPostgreSQLEventTriggerConfig, dbName, schemas[0], "test_event"),
        Check: resource.ComposeTestCheckFunc(
            testAccCheckPostgresqlEventTriggerExists("postgresql_event_trigger.event_trigger", dbName),
        ),
    },
    {
        Config: fmt.Sprintf(testAccPostgreSQLEventTriggerConfig, dbName, schemas[0], "test_event_renamed"),
        Check: resource.ComposeTestCheckFunc(
            testAccCheckPostgresqlEventTriggerExists("postgresql_event_trigger.event_trigger", dbName),
        ),
    },

In this case, this test will fail with:

Error: pq: event trigger "test_event_renamed" does not exist

You can simply check here if the name changed with something like:

	if d.HasChange(eventTriggerNameAttr) {
		old, new := d.GetChange(eventTriggerNameAttr)
		if _, err := txn.Exec(
			fmt.Sprintf("ALTER EVENT TRIGGER %s RENAME TO %s", pq.QuoteIdentifier(old), pq.QuoteIdentifier(new)),
		); err != nil {
			return err
		}
	}

[Fabianoshz]

I've just added a rename, I've also added your step to the tests too.

[Fabianoshz]

@cyrilgdn thanks for throughout review, I will start working on fixing in the next few days

[Fabianoshz]

@cyrilgdn sorry for the delay, I've addressed your requests, let me know if you think I should change anything, I will also test this on my environment in the meantime.

[Fabianoshz]

I've just added a rename, I've also added your step to the tests too.

[Fabianoshz]

I've added a map to fix this

[Temurson]

My organization would also benefit from this feature! @Fabianoshz really appreciate your contribution here.
@cyrilgdn please let me know if I can help in any way to get this feature in!