This plugin adds the possibility to add CloudFormation parameters to your Serverless applications. This is convenient if you want to just generate a CloudFormation template, and use it as a subtemplate for some other stack, or when you are deploying somethign manually or via a cloudformation deploy button.

Install the plugin through npm: npm install serverless-parameters. Add it your Serverless plugin list:

plugins:
  - serverless-parameters

After installation, you can now add parameters to the custom key:

custom:
  parameters:
    EnableFeatureX:
      Type: String
      AllowedValues: yes,no
      Default: yes
      Description: Enable feature X
    VPCId:
      Type: AWS::EC2::VPC::Id
      Description: Select the VPC you want to use
    SomeEnvVarPrefilled:
      Type: String
      Default: ${env:MY_ENV_VAR}
      Description: A default parameter, filled with a value from your env when deployed with `sls deploy`

All the properties are added to the template as-is, so you can use any of the CloudFormation parameter properties.

You can then add Ref's on the places where you want to use them, eg in your environment settings:

provider:
  name: aws
  environment:
    FEATURE_X:
      Ref: EnableFeatureX
    some_env_var:
      Ref: SomeEnvVarPrefilled

Add option for adding AWS::CloudFormation::Interface descriptions and such. PR's are welcome!