docker_image build image even if file context and dockerfile doesn't change

[IlyesDemineExtVeolia]

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Terraform (and docker Provider) Version

Affected Resource(s)

• docker_image

Terraform Configuration Files

resource "docker_image" "this" {
  name = local.ecr_image_name

  build {
    context    = var.source_path
    dockerfile = var.docker_file_path
    build_args = var.build_args
    platform   = var.platform
  }
}

Debug Output

Panic Output

Expected Behaviour

Don't build and deploy if context and dockerfile doesn't change

Actual Behaviour

Build and Deploy at each terraform apply

Steps to Reproduce

1. terraform apply

Important Factoids

References

• #0000

[vnghia]

I found that the build will be retriggered if the content of (file, subfolder, etc) your context folder change, which makes sense because the provider does not know which file in the context folder will be used (e.g COPY or ADD could copy them into the image) while building the Dockerfile.

[asmisha]

In my case the build is triggered even if the content has not changed. I suspect that it's auth_config that causes the rebuild due to changing credentials.

[samuelcortinhas]

I've also come across this bug. Our use case was to build an image from a dockerfile in a folder src/example and push it to an AWS ECR repository. We wanted to only rebuild/push image when there were changes to the code in src/example. However, even with the triggers hash is the same, the docker_image is being rebuilt every time.

resource "docker_registry_image" "registry_image" {
  name = docker_image.image.name
}

resource "docker_image" "image" {
  name = "${aws_ecr_repository.repository.repository_url}:latest"

  build {
    context = "${path.module}/src/example"
  }
  triggers = {
    dir_sha1 = sha1(join("", [for f in fileset(path.module, "src/example/**") : filesha1(f)]))
  }
}

Our solution was to rollback to version 2.25.0 of kreuzwerker/docker. (note the above configuration needs changing for this version).