Merge pull request 'switch app to official discourse/discourse image (with idempotent migration)' (#16) from discourse-official into main

Reviewed-on: https://git.coopcloud.tech/coop-cloud/discourse/pulls/16

release/next

@@ -2,6 +2,8 @@ This release switches from the bitnami image to the official discourse/discourse
 image. Some env vars need to be renamed for this migration; everything else
 should happen automatically.
 
+** WARNING A: renaming env vars
+
 Rename these in your app's .env (the values carry over):
 
   DISCOURSE_SMTP_HOST     --> DISCOURSE_SMTP_ADDRESS
@@ -9,7 +11,17 @@ Rename these in your app's .env (the values carry over):
   DISCOURSE_SMTP_AUTH     --> DISCOURSE_SMTP_AUTHENTICATION
   DISCOURSE_SMTP_PROTOCOL --> DISCOURSE_SMTP_ENABLE_START_TLS (takes a boolean true/false, not the old tls/ssl value, so translate it rather than copying it straight across)
 
-WARNING: if your deployment's database has an "install user" other than `postgres`
+** WARNING B: undeploy before deploy 
+
+it is necessary to `abra app undeploy` your old discourse app before deploying this version. otherwise the database will get killed and be in a bad state before the migration. 
+this was a non-fatal error in testing, but still a huge pain. 
+
+`abra app undeploy YOURDOMAIN` # cleaning stops your discourse
+`abra app deploy YOURDOMAIN` # with the new version 
+
+** WARNING C: install user
+
+if your deployment's database has an "install user" other than `postgres`
 (some older deployments do), you must set the POSTGRES_USER env var in your .env
 for this migration, otherwise the postgres upgrade aborts with an install-user
 mismatch.