WIP Prepare postgres for migration by replication

site-cookbooks/kosmos_postgresql/templates/create_subscription.sh.erb

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -euo pipefail
+
+DB_NAME="${1:?Usage: $0 <database_name>}"
+
+echo "== Processing DB: $DB_NAME =="
+
+SLOT="migrate_slot_${DB_NAME}"
+SUB="migrate_sub_${DB_NAME}"
+
+psql -d "$DB_NAME" -v ON_ERROR_STOP=1 <<SQL
+DO \$\$
+BEGIN
+  IF NOT EXISTS (
+    SELECT 1 FROM pg_subscription WHERE subname = '$SUB'
+  ) THEN
+    CREATE SUBSCRIPTION $SUB
+    CONNECTION 'host=<%= @pg_host %> port=<%= @pg_port %> dbname=$DB_NAME user=<%= @pg_user %> password=<%= @pg_pass %>'
+    PUBLICATION migrate_pub
+    WITH (
+      slot_name = '$SLOT',
+      create_slot = false,
+      copy_data = false,
+      enabled = true
+    );
+  END IF;
+END
+\$\$;
+SQL
+
+echo "== Done =="