WIP Prepare postgres for migration by replication

site-cookbooks/kosmos_postgresql/files/create_publication.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -euo pipefail
+
+DB_NAME="${1:?Usage: $0 <database_name>}"
+
+echo "== Processing DB: $DB_NAME =="
+
+# Create publication (idempotent)
+psql -d "$DB_NAME" -v ON_ERROR_STOP=1 <<'SQL'
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT 1 FROM pg_publication WHERE pubname = 'migrate_pub'
+  ) THEN
+    CREATE PUBLICATION migrate_pub FOR ALL TABLES;
+  END IF;
+END
+$$;
+SQL
+
+# Create logical replication slot (idempotent-ish)
+SLOT="migrate_slot_${DB_NAME}"
+
+if ! psql -d "$DB_NAME" -Atqc "SELECT 1 FROM pg_replication_slots WHERE slot_name = '$SLOT'" | grep -q 1; then
+  echo "  Creating slot: $SLOT"
+  psql -d "$DB_NAME" -c "SELECT pg_create_logical_replication_slot('$SLOT', 'pgoutput');"
+else
+  echo "  Slot already exists: $SLOT"
+fi
+
+echo "== Done =="