Passing buildah arguments

It is possible to pass arguments to buildah which is used to build container images in Konflux.

Using an arguments file

The Konflux buildah tasks accept BUILD_ARGS parameter that allows passing build arguments to the underlying buildah command through --build-arg-file flag. To enable this, make the following changes to the PipelineRuns under the .tekton/ directory:

Create a build args file in your repository. This should contain lines of build arguments in the form of arg=value.
Define a build-args-file Pipeline parameter (if not already present) in .spec.pipelineSpec.params to accept the passed-in build arguments.
```
spec:
  # ...
  pipelineSpec:
    params:
    # ...
    - name: build-args-file
      type: string
      default: ""
```

Pass the argument to buildah task. Add BUILD_ARGS_FILE to build-container.params (if not already present):

spec:
  # ...
  pipelineSpec:
    tasks:
    # ...
    - name: build-container
      params:
      # ...
      - name: BUILD_ARGS_FILE
        value: "$(params.build-args-file)"

Set the build arguments file in the PipelineRun .spec.params:

spec:
  params:
  # ...
  - name: build-args-file
    value: path/to/args-file  # Add the real path to the build args file within the build context

Setting arguments in the pipeline parameters

The Konflux buildah tasks accept BUILD_ARGS parameter that allows passing build arguments to the underlying buildah command through --build-arg flag. To enable this, make the following changes to the PipelineRuns under the .tekton/ directory:

Define a build-args Pipeline parameter (if not already present) in .spec.pipelineSpec.params to accept the passed-in build arguments.
```
spec:
  # ...
  pipelineSpec:
    params:
    # ...
    - name: build-args
      type: array
      default: []
```

Pass the argument to buildah task. Add BUILD_ARGS to build-container.params (if not already present):

spec:
  # ...
  pipelineSpec:
    tasks:
    # ...
    - name: build-container
      params:
      # ...
      - name: BUILD_ARGS
        value: ["$(params.build-args[*])"]

The value can also be in form tasks.<taskName>.results.<resultName>[*] if it is generated by another task dynamically.

For example, you can do more creative things with the BUILD_ARGS parameter like this snippet of a pipeline that allows passing build-args through the pipeline parameter (as described above) but also incorporates build-args generated dynamically by other tasks:

spec:
  # ...
  pipelineSpec:
    tasks:
    # ...
    - name: build-container
      params:
      # ...
      - name: BUILD_ARGS
        value:
        # pass the build args array from the pipeline param
        - $(params.build-args[*])
        # and a dynamically generated array of build args
        - $(tasks.my-build-arg-generator-task.results.BUILD_ARGS[*])
        # and a build arg with a static name and dynamic value
        - VERSION=$(tasks.my-get-version-task.results.VERSION)

Ensure that the value of BUILD_ARGS has the correct syntax as described in Variable Substitutions Supported by Tasks and Pipelines.

Pass the desired build arguments in the PipelineRun .spec.params:

spec:
  params:
  # ...
  - name: build-args
    value: ["ARG1=val", "ARG2=val"]  # Add real argument name and value of each build argument