@gemeentenijmegen/config

Config

Helpers for doing application config. The package includes a construct which creates (by default) a DynamoDB table for storing configuration, which can be provided an initial configuration.

Additionally, a runtime Config typescript-class is provided, which can retrieve config from a backend (currently, only dynamodb is supported). The config class can retrieve configuration by key, an JSON-compatible value is supported. Any config values which are aws Secrets Manager secret ARNs, or SSM parameter ARNs, will be retrieved and return the value. For this, the calling code must have access to the parameter/secret. Nested arns work as well.

Example usage

See demo/main.ts for a basic example. Using the construct:

const configTable = new ConfigTable(scope, 'config', {
  config: {
    myKey: 'myvalue2',
    anArrayKey: ['an', 'array'],
    secret: 'arn:aws:secretsmanager:us-west-2:123456789012:secret:my-path/my-secret-name-1a2b3c',
    nested: {
      objects: {
        withParameter: 'arn:aws:ssm:region:account-id:parameter/parameter-name'
      }
    }
  },
});

Using the runtime code:

const config = new Config();
await config.get('myKey'); // 'myvalue2'
await config.get('secret'); // secret value from provided arn

By default, the runtime Config() call will use the dynamodb-backend, and look for the table in process.env.APP_CONFIG_TABLENAME. To use a different table, inject a ConfigProvider:

new Config(new DynamoDbConfigProvider('myConfigTableName'));