Edit

Switching Backstage from SQLite to PostgreSQL

The default @backstage/create-app database is SQLite, an in-memory database that's perfect for initial experimentation as it requires no environment setup.

Once you're ready to deploy Backstage in production, or to have a more persistent development setup, you can switch the Backstage database to PostgreSQL.

Backstage uses the Knex library, making it fairly easy to switch between database backends.

Install PostgreSQL

First, add PostgreSQL to your backend package:

# From your Backstage root directory
yarn add --cwd packages/backend pg

Add PostgreSQL configuration

Next, modify app-config.yaml in the root folder to add PostgreSQL configuration for the backend:

backend:
  database:
-    client: better-sqlite3
-    connection: ':memory:'
+    # config options: https://node-postgres.com/api/client
+    client: pg
+    connection:
+      host: ${POSTGRES_HOST}
+      port: ${POSTGRES_PORT}
+      user: ${POSTGRES_USER}
+      password: ${POSTGRES_PASSWORD}
+      # https://node-postgres.com/features/ssl
+      # you can set the sslmode configuration option via the `PGSSLMODE` environment variable
+      # see https://www.postgresql.org/docs/current/libpq-ssl.html Table 33.1. SSL Mode Descriptions (e.g. require)
+      # ssl:
+      #   ca: # if you have a CA file and want to verify it you can uncomment this section
+      #     $file: <file-path>/ca/server.crt

If you have an app-config.local.yaml for local development, a similar update should be made there. You can set the POSTGRES_ environment variables prior to launching Backstage, or remove the ${...} values and simply set actual values directly for development.

The Backstage App is now ready to start up with a PostgreSQL backing database.

Override default PostgreSQL Database Pool Configuration

If you want to override the default connection pool settings then use the below configuration:

backend:
  database:
-    client: better-sqlite3
-    connection: ':memory:'
+    # config options: https://node-postgres.com/api/client
+    client: pg
+    connection:
+      host: ${POSTGRES_HOST}
+      port: ${POSTGRES_PORT}
+      user: ${POSTGRES_USER}
+      password: ${POSTGRES_PASSWORD}
+    # Refer to Tarn docs for default values on PostgreSQL pool configuration - https://github.com/Vincit/tarn.js
+    knexConfig:
+      pool:
+        min: 3
+        max: 12
+        acquireTimeoutMillis: 60000
+        idleTimeoutMillis: 60000
+      # https://node-postgres.com/features/ssl
+      # you can set the sslmode configuration option via the `PGSSLMODE` environment variable
+      # see https://www.postgresql.org/docs/current/libpq-ssl.html Table 33.1. SSL Mode Descriptions (e.g. require)
+      # ssl:
+      #   ca: # if you have a CA file and want to verify it you can uncomment this section
+      #     $file: <file-path>/ca/server.crt

Using a single database

By default, each plugin will get its own logical database, to ensure that there's no conflict in table names throughout the plugins that you install and to keep their concerns separate for other use cases further down the line. If you are limited in that you can only make use of a single database, you can use a special option pluginDivisionMode with client: pg in the config to create separate PostgreSQL Schemas instead of creating separate databases.

You can enable this using the following config:

backend:
  database:
    client: pg
    pluginDivisionMode: schema # defaults to database, but changing this to schema means plugins will be given their own schema (in the specified/default database)