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Reference Doppler Secrets

In Serverless Framework V.4, we introduced the ${doppler} variable, providing seamless integration with Doppler, a modern secrets management platform. This feature allows you to securely retrieve secrets from Doppler at deployment time, enhancing the security and flexibility of your serverless service.

You can quickly reference Doppler secrets with the following syntax:

service: my-service
provider:
  environment:
    DB_PASSWORD: ${doppler:my-project/DB_PASSWORD}

This will fetch the DB_PASSWORD secret from the stage you're deploying to in the my-project Doppler project. However, you MUST have the DOPPLER_TOKEN env var set.

For more advanced configuration, keep reading.

Configure the Doppler Resolver

stages:
  default:
    resolvers:
      doppler:
        type: doppler
        token: ${env:My_DOPPLER_TOKEN} # Your Doppler access token.
        project: backend-service # Your Doppler project
        config: dev # Doppler configs are equivalent to Serverless stages
  prod:
    resolvers:
      doppler:
        token: ${env:My_DOPPLER_TOKEN}
        project: backend-service
        config: prod

Configuration options:

• type - (required) - The type of resolver. Set it to doppler to use the Doppler resolver.
• token - (optional) - The Doppler token to authenticate with the Doppler service.
• project - (optional) - The Doppler project name to fetch secrets from
• config - (optional) - The Doppler config (environment) name to use, defaults to the current stage name you're running the framework in.

The token field is optional; however, in that case, the token must be set in either the DOPPLER_TOKEN or DOPPLER_ACCESS_TOKEN environment variable. An error will be thrown if no token is available.

The project field is optional. However, if not specified in the config, it must be provided in the variable reference (see below).

The config field is optional. If it isn't provided, it will default to the current stage name of your serverless service. For example, if you deploy with serverless deploy --stage prod, it will use "prod" as the config name.

Using the doppler resolver

There are two ways to reference secrets from Doppler:

1. With project configured in resolver:

When the project is specified in the resolver configuration as shown above, you can directly reference the secret name:

service: my-service
provider:
  environment:
    DB_PASSWORD: ${doppler:DB_PASSWORD}
    API_KEY: ${doppler:API_KEY}

2. With project specified in variable reference:

If you haven't specified a project in the resolver configuration, or want to override it, you can include the project name in the variable reference:

service: my-service
provider:
  environment:
    DB_PASSWORD: ${doppler:backend-service/DB_PASSWORD}
    API_KEY: ${doppler:frontend-service/API_KEY}

Using Multiple Projects or Environments

Doppler's configs (environments) map naturally to Serverless Framework stages. A common pattern is to use the same project across different environments:

stages:
  dev:
    resolvers:
      doppler:
        type: doppler
        project: backend-service
        # config will default to "dev"
  staging:
    resolvers:
      doppler:
        type: doppler
        project: backend-service
        # config will default to "staging"
  prod:
    resolvers:
      doppler:
        type: doppler
        project: backend-service
        # config will default to prod

Error Handling

The resolver will throw clear error messages in these cases:

• No token available in config or environment variables
• No project specified (either in config or variable reference)
• Invalid format when specifying project in variable reference
• Authentication failures with Doppler
• Other API errors from Doppler (with detailed error messages)