Database Service

This service lets your plugins get a knex client hooked up to a database which is configured in your app-config YAML files, for your persistence needs.

If there's no config provided in backend.database then you will automatically get a simple in-memory SQLite 3 database for your plugin whose contents will be lost when the service restarts.

This service is scoped per plugin too, so that table names do not conflict across plugins.

Using the service

The following example shows how to get access to the database service in your example backend plugin and getting a client for interacting with the database. It also runs some migrations from a certain directory for your plugin.

import {
  coreServices,
  createBackendPlugin,
} from '@backstage/backend-plugin-api';
import { resolvePackagePath } from '@backstage/backend-common';

createBackendPlugin({
  pluginId: 'example',
  register(env) {
    env.registerInit({
      deps: {
        database: coreServices.database,
      },
      async init({ database }) {
        const client = await database.getClient();
        const migrationsDir = resolvePackagePath(
          '@internal/my-plugin',
          'migrations',
        );
        if (!database.migrations?.skip) {
          await client.migrate.latest({
            directory: migrationsDir,
          });
        }
      },
    });
  },
});