Advanced Features

Advanced features and detailed information for using Serverless Framework with Runway.

Disabling NPM CI

At the start of each module execution, Runway will execute npm ci to ensure Serverless Framework is installed in the project (so Runway can execute it via npx sls). This can be disabled (e.g. for use when the node_modules directory is pre-compiled) via the skip_npm_ci module option.

Example

deployments:
  - modules:
      - path: myslsproject.sls
        options:
          skip_npm_ci: true

Extending a Serverless Configuration File

Runway has the ability to extend the contents of a serverless.yml file using the value of the extend_serverless_yml option. The value of this option is recursively merged into a resolved clone of the module’s Serverless configuration. To create this resolved clone, Runway uses “serverless print” (including args) to resolve the module’s Serverless configuration file and output the contents to a temporary file. The temporary file is deleted after each execution of Runway.

This functionality can be especially useful when used alongside remote module paths such as a module from a git repository to change values on the fly without needing to modify the source for small differences in each environment.

Example

deployments:
  - modules:
      - path: git::git://github.com/onicagroup/example.git//sampleapp?tag=v1.0.0
        options:
          extend_serverless_yml:
            custom:
              env:
                memorySize: 512
    regions:
      - us-east-1

Merge Logic

The two data sources are merged by iterating over their content and combining the lowest level nodes possible.

Example

serverless.yml
functions:
  example:
    handler: handler.example
    runtime: python3.8
    memorySize: 512
runway.yml
deployments:
  - modules:
      - path: sampleapp.sls
        options:
          extend_serverless_yml:
            functions:
              example:
                memorySize: 1024
            resources:
              Resources:
                ExampleResource:
                  Type: AWS::CloudFormation::WaitConditionHandle
    regions:
      - us-east-1
Resulting serverless.yml
functions:
  example:
    handler: handler.example
    runtime: python3.8
    memorySize: 1024
  resources:
    Resources:
      ExampleResource:
        Type: AWS::CloudFormation::WaitConditionHandle

Promoting Builds Through Environments

Serverless build .zips can be used between environments by setting the promotezip module option and providing a bucket name in which to cache the builds.

The first time the Serverless module is deployed using this option, it will build/deploy as normal and cache the artifact on S3. On subsequent deploys, Runway will used that cached artifact (finding it by comparing the module source code).

This enables a common build account to deploy new builds in a dev/test environment, and then promote that same zip through other environments. Any of these environments can be in the same or different AWS accounts.

The CloudFormation Stack deploying the zip will be re-generated on each deployment so environment-specific values/lookups will work as normal.

Example

deployments:
  - modules:
      - path: myslsproject.sls
        options:
        promotezip:
          bucketname: my-build-account-bucket-name

Specifying Serverless CLI Arguments/Options

Runway can pass custom arguments/options to the Serverless CLI by using the args option. These will always be placed after the default arguments/options.

The value of args must be a list of arguments/options to pass to the CLI. Each element of the argument/option should be it’s own list item (e.g. --config sls.yml would be ['--config', 'sls.yml']).

Important

Do not provide --region <region> or --stage <stage> here, these will be provided by Runway. Runway will also provide --no-color if stdout is not a TTY.

Example

runway.yml
deployments:
  - modules:
      - path: sampleapp.sls
        options:
          args:
            - '--config'
            - sls.yml
    regions:
      - us-east-2
    environments:
      example: true
Command equivalent
$ serverless deploy -r us-east-1 --stage example --config sls.yml