SAM CDK -> sam build -> DockerImageCode.from_image_asset: Unable to set parent folder as the DockerContext

Description:

I am having trouble with the following setup.

I have the following folder structure:

/root
  .Pipfile
  /shared_dependencies
  /project
    /runtime
      DockerFile

I need to set /root as the DockerContext and /root/project/runtime/DockerFile as the path to the Dockerfile

If I create a DockerImageCode instance and use it to create a DockerImageFunction like so:

code = DockerImageCode.from_image_asset(
  directory="/filesystem_path/root",
  file="/project/runtime/DockerFile",
)

DockerImageFunction(
  code=code,
)

cdk synth >| template.yaml will output a template and an AWS:Serverless:Function resource with the following metadata:

Metadata:
  aws:asset:path: /filesystem_path/root
  aws:asset:dockerfile-path: /project/runtime/DockerFile

My DockerFile contains the following:

COPY Pipfile .

To facilitate local development, I need to run sam build. When I do so, I get the following error:

COPY failed: file not found in build context or excluded by .dockerignore:
 stat Pipfile: file does not exist

Upon inspecting .aws-sam/build.toml, it would seem that the DockerContext is being set to /filesystem_path/root/project/runtime, the folder in which the DockerFile resides.

I would have assumed that the DockerContext would correspond to the directory parameter that gets passed into DockerImageCode.from_image_asset? (Which corresponds to aws:asset:path in the template)

As far as I can tell, there is no way of setting the DockerContext to any folder that is not the folder in which the DockerFile resides.

This pull request added the mapping logic for cdk image asset metadata -> sam build params.

Looking at the changes in this file, it would seem that the DockerContext will always be equal to the folder in which the DockerFile resides.

Is there a way of setting the DockerContext that I am not aware of? Or is it currently impossible?

I came across this issue which is now closed but does not offer a satisfactory resolution to this problem.

Additional environment details:

OS: Mac

sam --version -> SAM CLI, version 1.53.0

[mndeveci]

Changes have been released with SAM CLI v1.62.0

[i18n-tribe]

@jfuss I’ve submitted a PR to address this issue.

The code in the PR makes sam-cli behaviour consistent with how the cdk is working.