DockerImageAsset is missing build context

[KnisterPeter]

• I'm submitting a ...

  • 🪲 bug report
  • 🚀 feature request
  • 📚 construct library gap
  • ☎️ security issue or vulnerability => Please see policy
  • ❓ support request => Please see note at the top of this template.

• What is the current behavior?
  If the current behavior is a 🪲bug🪲: Please provide the steps to reproduce

Right now there is not option to specify the build context for the docker build.
E.g. if the Dockerfile requires files from .. the build context need to be at least '..' instead of '.' which is the default.

• What is the expected behavior (or behavior of feature suggested)?

There should be an option to specify the context. This could be tricky, since CDK stages the files which would then mean to stage the entire build context.

• What is the motivation / use case for changing the behavior or adding this feature?

It is an advanced use case for building docker images in for example mono-repositories where there are dependencies into other folders.

• Please tell us about your environment:

  • CDK CLI Version: 0.36.0
  • Module Version: 0.36.0
  • OS: all
  • Language: TypeScript

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. associated pull-request, stackoverflow, gitter, etc)

[rix0rrr]

I'm going to need more context. DockerImageAsset takes a directory parameter. Does that not suffice?

[KnisterPeter]

If the folder your docker file is in requires files outsite site folder (up in the fs hierarchy) you need to define a build context.
By default this context is the Directory where the Dockerfile lives. But that isn't required.

https://docs.docker.com/engine/reference/commandline/build/

[mbruning24]

@rix0rrr a good use case for this (at least IMO) is when you have multiple Dockerfiles and they each use the same build context. I'm building a selenium testing environment where I have chrome and firefox images that I want to utilize the same set of nodejs scripts to handle running (protractor, cucumber, etc etc etc) and I want to manage them both in the same CDK project without having to copy the files.

In that case it would be awesome to either pass a custom dockerfile location (like #3829):

{ directory: '.', dockerfile: 'lib/xyz/chrome/Dockerfile' }
...
{ directory: '.', dockerfile: 'lib/xyz/firefox/Dockerfile' }

Or to allow overriding contextPath when docker images are built.

[eladb]

@SomayaB please assign all asset issues to me :)

[kingwill101]

i believe this would be a great solution to the issue i'm currently having https://stackoverflow.com/questions/58838213/allowing-stack-to-create-multiple-ecr-images

[eladb]

@iliapolo do you think this is something or this will make asset staging hell?

[iliapolo]

@eladb I think exposing the context directory might introduce a slue of unnecessary problems. I believe the issues discussed here can be better solved otherwise.

@mbruning24 We have now added support for custom docker files: (#3829). Does this solve the issue you were facing?

@glenfordwilliams Its been a while since your latest comment and I think the issue you addressed should now simply work. The buildArgs are considered when creating the asset hash, which means that a different image is created for each buildArgs combo. Note that we now don't create a separate ECR repo for every image, but rather put all of them in a shared one.

But I think this should still be ok because i believe the initial problem was that it didn't actually create separate images based on the build args, right?

[SomayaB]

Closing for now since there hasn't been a response in a while. Feel free to reopen.

[Kilowhisky]

I know this is closed but this just happened to me today. For example if you are trying to build a Docker image from a VS C# project, the context has to be set to .. . See https://learn.microsoft.com/en-us/visualstudio/containers/container-build?view=vs-2022#docker-build

To build a containerized solution from the command line, you can usually use the command docker build for each project in the solution. You provide the build context argument. The build context for a Dockerfile is the folder on the local machine that's used as the working folder to generate the image. For example, it's the folder that you copy files from when you copy to the container. In .NET Core projects, use the folder that contains the solution file (.sln). Expressed as a relative path, this argument is typically ".." for a Dockerfile in a project folder, and the solution file in its parent folder. For .NET Framework projects, the build context is the project folder, not the solution folder.

It is currently not possible to do this with DockerImageAsset if you are using C# as the CDK language. Which means, you cannot easily build VisualStudio based Dockerfile projects.

[mluksch]

Would be great, if this could get reopened again.
There is currently no way afaik to separate the "build context" from the "dockerfile" in cdk with DockerImageCode. With the status quo the Dockerfile has to be placed within the build context. But this makes it difficult to write a custom Construct that already contains a Dockerfile but where you just want to parameterize the build context with the source code on the consuming side of the custom Construct.

// LambdaWebApp = a Custom Construct imported from an npm-dependency
import { LambdaWebApp } from "common-infra-lib";

  new LambdaWebApp(this, "test", {
    code: cdk.aws_lambda.DockerImageCode.fromImageAsset(
        // This is the build context with the source code:
         "..", {
         // This Dockerfile should rather get provided by the custom construct in the npm-dependency 
         // itself, but this isnt possible yet because the Dockerfile has to be placed in the build context here:
         file: "ProdDockerfile",
    }),
    subdomain: "test",
  });

[andrew-hossack]

Any updates on this would be greatly appreciated.

[xbreid]

+1

[fernicolosi]

I was having the same issue and a combination of directory and file properties did the trick for me:

import { DockerImageAsset } from "aws-cdk-lib/aws-ecr-assets";

const image = new DockerImageAsset(this, "Image", {
  directory: "../../../", <--- This is the path to your docker build context 
  file: "[PATH-TO-DOCKERFILE]/Dockerfile",
});