| Fix the following issue: |
|
|
| # Run custom database-initialization SQL after a cluster comes up |
|
|
| Users want a way to have the operator run their own SQL against a freshly |
| initialized PostgresCluster — e.g. to `CREATE EXTENSION`, seed reference tables, |
| or create application objects — without manually `exec`-ing into a pod. We want |
| to support pointing the cluster at a ConfigMap that holds a SQL file and have |
| the operator execute it once the cluster is running. |
|
|
| ## API |
|
|
| Add an optional field to the `PostgresCluster` **spec** called `databaseInitSQL`. |
| It is an object that references a ConfigMap living in the same namespace as the |
| cluster, with two required string sub-fields: |
|
|
| - `name` — the name of the ConfigMap. |
| - `key` — the data key inside that ConfigMap whose value is the SQL to run. |
|
|
| Add an optional **status** field, also called `databaseInitSQL` (a string). Its |
| presence records that the initialization SQL has been applied successfully. |
|
|
| Both new types must support the project's deep-copy conventions (copying a |
| cluster must produce an independent copy of these values). |
|
|
| ## Behavior |
|
|
| Hook this into the reconcile loop as an additional step. Expose that step as a |
| method on the reconciler with the signature |
|
|
| ```go |
| func (r *Reconciler) reconcileDatabaseInitSQL(ctx context.Context, |
| cluster *v1beta1.PostgresCluster, instances *observedInstances) error |
| ``` |
|
|
| so it can be driven directly. The `instances` argument is the set of observed |
| instances for the cluster. The step must behave as follows: |
|
|
| - **Spec absent.** If `spec.databaseInitSQL` is not set, the status field must be |
| cleared (set back to nil) and the step returns without doing anything else. In |
| particular it must never try to execute SQL. |
|
|
| - **Already applied.** If `spec.databaseInitSQL` is set but the status field is |
| already set, the step is a no-op: it must not execute SQL and must leave the |
| status unchanged. |
|
|
| - **Needs applying.** If `spec.databaseInitSQL` is set and the status is not yet |
| set, the step attempts to apply the SQL: |
| - Fetch the named ConfigMap from the cluster's namespace. If it cannot be |
| fetched, return that error (e.g. a not-found error from the API surfaces |
| unchanged) without executing SQL. |
| - If the ConfigMap exists but does not contain the requested `key`, return an |
| error whose message identifies the missing key, without executing SQL. |
| - Find the instance that is running, non-terminating, and writable (the |
| primary), and execute the SQL string against its database container, passing |
| the SQL on standard input. If no such instance is currently available, the |
| step returns without error and without setting the status (so it is retried |
| on a later reconcile). |
| - If execution succeeds, set the status field so the SQL will not run again. |
| If execution fails, return the error and leave the status unset so it is |
| retried. |
| |
| Because the status can be lost or the field re-added, the SQL may run more than |
| once; that is acceptable and is the user's responsibility to make idempotent. |
|
|
