Dynamic task modification

In our use case, we need to modify some of our task definition parameters and use values that are known just during deployment. For example, We need to provide to our component env variable VERSION:

{
   "environment": [
        {
          "name": "VERSION",
          "value": "7.0.1476"
        }
      ],
}

Some general mechanism for replacing placeholders with wanted value would be really helpful. For example we could define

{
    "environment": [
        {
          "name": "VERSION",
          "value": "#VERSION#"
        }
      ],
}

And pass there the correct value:

    - name: Render Amazon ECS task definition
      id: render-task-definition
      uses: aws-actions/amazon-ecs-render-task-definition@v1
      with:
        task-definition: abc
        container-name: abc
        image: abc
        replacement_pattern: #VERSION#
        replacement_value: ${{steps.version.outputs.prop}}

The action would replace the replacement_pattern (regexp) with replacement_value.
Would be possible to add this or similar functionality ?

[faraquet]

@neugeeug thanks for bringing up this topic. This would be a very useful feature, I was just looking for something similar right now!

[allisaurus]

@neugeeug thanks very much for the suggestion and PR! We’ve seen similar requests re: interpolating stage/env specific-values into a task definition before, but so far haven’t landed on a choice re: implementation.

The linked approach (merging a task def ‘fragment’) strikes me as more extensible b/c you can apply a whole set of changes at once vs. a specific value. I understand the use cases may be somewhat different (to merge a JSON ‘fragment’ you need to have or add the JSON in a file, where for a single value creating a JSON string is more overhead), but I could be missing something. What do you think about a more general “merge” capability?