Merge pull request #27956 from backstage/blam/small-changes

postgres: set the `connection.type` to `default` when not provided

packages/backend-defaults/src/entrypoints/database/connectors/postgres.test.ts

@@ -220,6 +220,41 @@ describe('postgres', () => {
         useNullAsDefault: true,
       });
     });
+
+    it('throws an error when the connection type is not supported', async () => {
+      await expect(
+        buildPgDatabaseConfig(
+          new ConfigReader({
+            client: 'pg',
+            connection: {
+              type: 'not-supported',
+            },
+          }),
+        ),
+      ).rejects.toThrow('Unknown connection type: not-supported');
+    });
+
+    it('supports default as the default connection type', async () => {
+      await expect(
+        buildPgDatabaseConfig(
+          new ConfigReader({
+            client: 'pg',
+            connection: {
+              type: 'default',
+              port: '5432',
+              database: 'other_db',
+            },
+          }),
+        ),
+      ).resolves.toEqual({
+        client: 'pg',
+        connection: {
+          port: '5432',
+          database: 'other_db',
+        },
+        useNullAsDefault: true,
+      });
+    });
   });
 
   describe('getPgConnectionConfig', () => {

packages/backend-defaults/src/entrypoints/database/connectors/postgres.ts

@@ -77,44 +77,48 @@ export async function buildPgDatabaseConfig(
     overrides,
   );
 
-  if (config.connection?.type === 'cloudsql') {
-    if (config.client !== 'pg') {
-      throw new Error('Cloud SQL only supports the pg client');
-    }
+  const sanitizedConfig = JSON.parse(JSON.stringify(config));
 
-    if (!config.connection.instance) {
-      throw new Error('Missing instance connection name for Cloud SQL');
-    }
+  // Trim additional properties from the connection object passed to knex
+  delete sanitizedConfig.connection.type;
+  delete sanitizedConfig.connection.instance;
 
-    const {
-      Connector: CloudSqlConnector,
-      IpAddressTypes,
-      AuthTypes,
-    } = await import('@google-cloud/cloud-sql-connector');
-    const connector = new CloudSqlConnector();
-    const clientOpts = await connector.getOptions({
-      instanceConnectionName: config.connection.instance,
-      ipType: IpAddressTypes.PUBLIC,
-      authType: AuthTypes.IAM,
-    });
-
-    const cloudsqlConfig = {
-      ...config,
-      client: 'pg',
-      connection: {
-        ...config.connection,
-        ...clientOpts,
-      },
-    };
-
-    // Trim additional properties from the connection object passed to knex
-    delete cloudsqlConfig.connection.type;
-    delete cloudsqlConfig.connection.instance;
-
-    return cloudsqlConfig;
+  if (config.connection.type === 'default' || !config.connection.type) {
+    return sanitizedConfig;
   }
 
-  return config;
+  if (config.connection.type !== 'cloudsql') {
+    throw new Error(`Unknown connection type: ${config.connection.type}`);
+  }
+
+  if (config.client !== 'pg') {
+    throw new Error('Cloud SQL only supports the pg client');
+  }
+
+  if (!config.connection.instance) {
+    throw new Error('Missing instance connection name for Cloud SQL');
+  }
+
+  const {
+    Connector: CloudSqlConnector,
+    IpAddressTypes,
+    AuthTypes,
+  } = await import('@google-cloud/cloud-sql-connector');
+  const connector = new CloudSqlConnector();
+  const clientOpts = await connector.getOptions({
+    instanceConnectionName: config.connection.instance,
+    ipType: IpAddressTypes.PUBLIC,
+    authType: AuthTypes.IAM,
+  });
+
+  return {
+    ...sanitizedConfig,
+    client: 'pg',
+    connection: {
+      ...sanitizedConfig.connection,
+      ...clientOpts,
+    },
+  };
 }
 
 /**