Parameterized Promotions#

The parameterized promotions feature allows users to pass parameters to promotion pipelines. You can do this either via a form in the UI, via the Semaphore API, or on auto-promotions by setting up default values.

The core advantage of this feature is code reusability. It is no longer necessary to create many promotion pipelines with almost identical configurations. Users can now create a single pipeline and rely on parameters for smaller but critical differences.

Configuring the promotion parameters#

Let's start by defining the parameters that our promotion will support.

In your .yml file, when defining the promotion you can set up as many parameters as you want.

Possible options include:

  • required: values (true/false) - If the parameter is required and default_value is not set the promotion won’t start.
  • default_value - Can only be set if the parameter is required. It is a default value of the parameter.
  • options - Use this to define a list of all possible values. The user needs to select a value from the dropdown menu. If omitted, the user is able to input any value via the input box.
  • description - This is a description text that gets rendered on the promotion UI (when a user selects values).
  • name - This is the name of the parameter and the exported environment variable (referenced later in the promoted pipelines).

Here is an example of setting the two parameters for a single promotion:

# .semaphore/semaphore.yml
version: v1.0
name: Parameterized Promotion
agent:
  machine:
    type: e1-standard-2
    os_image: ubuntu2004
blocks:
  - name: Promotions
    task:
      jobs:
        - name: Everything
          commands:
            - echo 'Running tests'
promotions:
  - name: Deploy
    pipeline_file: deploy.yml
    # Define promotion parameters
    parameters:
      env_vars:
        - required: true
          options:
            - Stage
            - Production
          default_value: Stage
          description: Where to deploy?
          name: ENVIRONMENT

        - required: false
          description: Release name?
          name: RELEASE

You can also use the in-app Workflow Editor to define the parameters for the promotion like this:

Parameterized promotions in Workflow Editor

Using the parameter values in promoted pipeline#

Now that we have defined our parameters, it is time to define how to use them in the promoted pipeline.

You can use promotion parameters in the following way:

  • In the pipeline name
  • In the name of the pipeline queue
  • In the name of the secret

  • As an environment variable inside a job

  • In the pipeline name - this enables you to easily figure out specifics for the promotions in the UI.

  • In the name of the pipeline queue - so you can have separate queues for different kinds of promotions, e.g. staging and production deployments.
  • In the name of the secret - use only the specific secret you need to improve security.
  • As an environment variable inside a job

Let's create a deployment pipeline that uses promotion parameter values in all of the mentioned ways:

# .semaphore/deploy.yml
version: v1.0
# Use parameter values in the pipeline name
name: '${{parameters.ENVIRONMENT}} deployment of the release: ${{parameters.RELEASE}}'
agent:
  machine:
    type: e1-standard-2
    os_image: ubuntu2004
queue:
  # Use parameter values in the pipeline queue name
  name: '${{parameters.ENVIRONMENT}}-queue'
  scope: project
blocks:
  - name: Param. promotions example
    task:
      jobs:
        - name: Using promotion as env. var
          commands:
            # Use parameter values inside a job
            - echo $ENVIRONMENT
            - echo $RELEASE
      secrets:
        # Use parameter values when attaching a secret
        - name: 'creds-for-${{parameters.ENVIRONMENT}}'

Note: For this example pipeline to work, the secrets named creds-for-Production and creds-for-Stage must exist in the organization.

Setting the parameter values#

Now that you have configured both the initial pipeline and the promotion pipeline, we can start using parameterized promotions.

Values to the parameters are assigned every time a promotion is triggered. This can be done in the following ways:

  • In the UI form if the promotion is triggered manually
  • Via the API call
  • Via default_value in combination with auto_promote

Setting the values through the UI#

If you have a promotion set up you will see a deployment button in the Semaphore web interface.

When clicked, a UI form will be auto-generated based on the configuration of the initial pipeline. This will prompt you for parameter values before starting the promotion.

Here's how it looks like for the .yml code from our example:

Parameterized Promotions form on the Workflow Page

Setting the values via the API#

Parameters can also be passed to the promotion pipeline when the promotions are triggered via the Semaphore API.

The following is an example of a curl call that includes parameters:

curl -H "Authorization: Token {api_token}" \
     -d "name={promotion_name}&pipeline_id={parent_pipeline_id}&{param_1_name}={param_1_value}&{param_2_name}={param_2_value}" \
     -X POST "https://{org_name}.semaphoreci.com/api/v1alpha/promotions"

Setting the values through the default value#

If you are using the auto_promote to trigger the promotion, you can still set the value for the promotion parameters.

This can be done by utilizing the default_value option:

# .semaphore/semaphore.yml
version: v1.0
name: Parameterized Promotion
agent:
  machine:
    type: e1-standard-2
    os_image: ubuntu2004
blocks:
  - name: Promotions
    task:
      jobs:
        - name: Everything
          commands:
            - echo 'Running tests'
promotions:
  - name: Deploy
    pipeline_file: deploy.yml
    # Define promotion parameters
    auto_promote:
      when: pull_request =~ '.*' AND result = 'passed'
    parameters:
      env_vars:
        - required: true
          options:
            - Stage
            - Production
          default_value: Stage
          description: Where to deploy?
          name: ENVIRONMENT

        - required: true
          description: Release name?
          name: RELEASE
          default_value: Test release

In the example above, if auto-promotion is triggered, the value for $ENVIRONMENT will be Stage and the value for $RELEASE will be set to the name of the pull request.