[Bug]: `ImageFromDockerfileBuilder` breaking change in `4.8.0`

[alexaka1]

Testcontainers version

4.8.0

Using the latest Testcontainers version?

Yes

Host OS

Linux, MacOS

Host arch

x86, arm64

.NET version

9.0.306

Docker version

Client:
 Version:           28.5.1
 API version:       1.51
 Go version:        go1.24.8
 Git commit:        e180ab8
 Built:             Wed Oct  8 12:16:17 2025
 OS/Arch:           darwin/arm64
 Context:           desktop-linux

Server: Docker Desktop 4.48.0 (207573)
 Engine:
  Version:          28.5.1
  API version:      1.51 (minimum version 1.24)
  Go version:       go1.24.8
  Git commit:       f8215cc
  Built:            Wed Oct  8 12:18:25 2025
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.7.27
  GitCommit:        05044ec0a9a75232cad458027ca83437aae3f4da
 runc:
  Version:          1.2.5
  GitCommit:        v1.2.5-0-g59923ef
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Docker info

Client:
 Version:    28.5.1
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  ai: Docker AI Agent - Ask Gordon (Docker Inc.)
    Version:  v1.9.11
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-ai
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.29.1-desktop.1
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-buildx
  cloud: Docker Cloud (Docker Inc.)
    Version:  v0.4.39
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-cloud
  compose: Docker Compose (Docker Inc.)
    Version:  v2.40.0-desktop.1
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-compose
  debug: Get a shell into any image or container (Docker Inc.)
    Version:  0.0.44
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-debug
  desktop: Docker Desktop commands (Docker Inc.)
    Version:  v0.2.0
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-desktop
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.31
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-extension
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.4.0
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-init
  mcp: Docker MCP Plugin (Docker Inc.)
    Version:  v0.23.0
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-mcp
  model: Docker Model Runner (Docker Inc.)
    Version:  v0.1.42
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-model
  offload: Docker Offload (Docker Inc.)
    Version:  v0.4.39
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-offload
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-sbom
  scout: Docker Scout (Docker Inc.)
    Version:  v1.18.3
    Path:     /Users/alexaka1/.docker/cli-plugins/docker-scout

Server:
 Containers: 7
  Running: 4
  Paused: 0
  Stopped: 3
 Images: 61
 Server Version: 28.5.1
 Storage Driver: overlayfs
  driver-type: io.containerd.snapshotter.v1
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Discovered Devices:
  cdi: docker.com/gpu=webgpu
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 05044ec0a9a75232cad458027ca83437aae3f4da
 runc version: v1.2.5-0-g59923ef
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.10.14-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: aarch64
 CPUs: 12
 Total Memory: 46.97GiB
 Name: docker-desktop
 ID: aa7eda8c-ffd8-4bfc-b6bc-8c317e4d9cc3
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Labels:
  com.docker.desktop.address=unix:///Users/alexaka1/Library/Containers/com.docker.docker/Data/docker-cli.sock
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false

What happened?

My tests are unable to run on the Renovate branch that updates to 4.7.0: alexaka1/distroless-dotnet-healthchecks#869

For example here: https://github.com/alexaka1/distroless-dotnet-healthchecks/actions/runs/18673678080/job/53239457620?pr=869#step:10:27

It says:

/_/src/Docker.DotNet/DockerClient.cs(516): error test failed: Distroless.HealthChecks.Test.HealthyTests.Net10.Runtime10AotContainerTest.Container_is_healthy(image: "mcr.microsoft.com/dotnet/nightly/runtime", runtimeTag: "10.0-preview@sha256:89f9ea57c1245b919a5f9bd94226d9"···, targetFramework: "10.0", dockerfile: "test/Distroless.Sample.WebApp/Dockerfile") (22s 904ms): Docker.DotNet.DockerApiException : Docker API responded with status code=InternalServerError, response={"message":"Cannot locate specified Dockerfile: test/Distroless.Sample.WebApp/Dockerfile"} [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:  [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed: Stack Trace: [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Docker.DotNet.DockerClient.HandleIfErrorResponseAsync(HttpStatusCode statusCode, HttpResponseMessage response) in /_/src/Docker.DotNet/DockerClient.cs:line 516 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Docker.DotNet.DockerClient.MakeRequestForRawResponseAsync(HttpMethod method, String path, IQueryString queryString, IRequestContent body, IDictionary`2 headers, CancellationToken token) in /_/src/Docker.DotNet/DockerClient.cs:line 331 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Docker.DotNet.Models.StreamUtil.MonitorResponseForMessagesAsync[T](Task`1 responseTask, DockerClient client, CancellationToken cancel, IProgress`1 progress) in /_/src/Docker.DotNet/Endpoints/StreamUtil.cs:line 80 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at DotNet.Testcontainers.Clients.DockerImageOperations.BuildAsync(IImageFromDockerfileConfiguration configuration, ITarArchive dockerfileArchive, CancellationToken ct) in /_/src/Testcontainers/Clients/DockerImageOperations.cs:line 122 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at DotNet.Testcontainers.Clients.TestcontainersClient.BuildAsync(IImageFromDockerfileConfiguration configuration, CancellationToken ct) in /_/src/Testcontainers/Clients/TestcontainersClient.cs:line 398 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at DotNet.Testcontainers.Images.FutureDockerImage.UnsafeCreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 145 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at DotNet.Testcontainers.Images.FutureDockerImage.CreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 112 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Init(TestData data, CancellationToken cancellationToken) in /home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 96 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Container_is_healthy(String image, String runtimeTag, String targetFramework, String dockerfile) in /home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 44 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed:    at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Container_is_healthy(String image, String runtimeTag, String targetFramework, String dockerfile) in /home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 60 [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]
/_/src/Docker.DotNet/DockerClient.cs(516): error test failed: --- End of stack trace from previous location --- [/home/runner/work/distroless-dotnet-healthchecks/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj]

My tests basically do the following:

• build an image from a dockerfile
• configure a container with said image
• run tests

string baseImageType = Utils.CurrentBaseImageType();
        string healthCheckImage = Utils.HealthCheckImage();
        _image = new ImageFromDockerfileBuilder()
            .WithDockerfile(data.Dockerfile)
            .WithBuildArgument("RUNTIME_TAG", data.RuntimeTag)
            .WithBuildArgument("TARGET_FRAMEWORK", data.TargetFramework)
            .WithBuildArgument("IMAGE", data.Image)
            .WithBuildArgument("BASE_IMAGE_TYPE", baseImageType)
            .WithBuildArgument("HEALTHCHECK_IMAGE", healthCheckImage)
            .WithDockerfileDirectory(CommonDirectoryPath.GetSolutionDirectory(), "")
            .Build();
        await _image.CreateAsync(cancellationToken)
            .ConfigureAwait(false); // <---- exception here ##########################
        _container = new ContainerBuilder()
            .WithImage(_image)
            .WithWaitStrategy(Wait.ForUnixContainer().UntilMessageIsLogged(
                    Regex.Escape("Application started. Press Ctrl+C to shut down."),
                    strategy => strategy.WithTimeout(TimeSpan.FromSeconds(30)))
                .UntilContainerIsHealthy(3,
                    strategy => strategy.WithTimeout(TimeSpan.FromSeconds(30)))
            )
            .WithEnvironment("DISTROLESS_HEALTHCHECKS_Uri", "http://localhost:8080/healthz")
            .Build();

And every single one of them fails when it comes to building the dockerfile.

Relevant log output

Additional information

With .NET 9 SDK and docker installed, check out this repo and run one of the test classes

CI=true dotnet test -c Release test/Distroless.HealthChecks.Test/Distroless.HealthChecks.Test.csproj -- --filter-class "*AspNet9AotContainerTest*" 

The project has a lot of tests, so don't just blanket run all of them, or else you'll be sitting there for a good while.

The tests fail both locally on macos and in CI on ubuntu-latest

[HofmeisterAn]

Could you please enable the debug log messages by setting ConsoleLogger.Instance.DebugLogLevelEnabled = true before creating any builder configuration? Then, share the output? I guess some files might not be found, and this could be related to the recent Docker context support.

[HofmeisterAn]

I'm sorry for the inconvenience. I think I've found the issue. The Dockerfile is ending up in the root directory /Dockerfile instead of in /test/Distroless.Sample.WebApp/Dockerfile. Could you please try the following configuration?

_ = new ImageFromDockerfileBuilder()
    .WithContextDirectory(CommonDirectoryPath.GetSolutionDirectory().DirectoryPath) // Set the path to the build context.
    .WithDockerfile("Dockerfile")
    .WithDockerfileDirectory(CommonDirectoryPath.GetSolutionDirectory(), "test/Distroless.Sample.WebApp/") // Set the path to the Dockerfile directory.

I need to look into this a little more to understand why it's necessary and work out the correct configuration. I don't think this came up in our tests. See: Choosing a build context too.

[alexaka1]

I have added debug logs, CI should start now on that PR. Will take a moment to complete, although should be fast.

WithContextDirectory

When I created this code, I don't think there was a WithContextDirectory api, so this very well could be it. I'll try locally.

[alexaka1]

This does not work:

var folder = Path.GetDirectoryName(data.Dockerfile); // becomes `test/Distroless.Sample.WebApp`
        var file = Path.GetFileName(data.Dockerfile); // becomes `Dockerfile`
        _image = new ImageFromDockerfileBuilder()
            .WithBuildArgument("RUNTIME_TAG", data.RuntimeTag)
            .WithBuildArgument("TARGET_FRAMEWORK", data.TargetFramework)
            .WithBuildArgument("IMAGE", data.Image)
            .WithBuildArgument("BASE_IMAGE_TYPE", baseImageType)
            .WithBuildArgument("HEALTHCHECK_IMAGE", healthCheckImage)
            .WithDockerfile(file)
            .WithContextDirectory(CommonDirectoryPath.GetSolutionDirectory().DirectoryPath)
            .WithDockerfileDirectory(CommonDirectoryPath.GetSolutionDirectory(), folder)
            .Build();

[HofmeisterAn]

I have added debug logs, CI should start now on that PR. Will take a moment to complete, although should be fast.

WithContextDirectory

When I created this code, I don't think there was a WithContextDirectory api, so this very well could be it. I'll try locally.

Yes, this is a new API. Previously, you couldn't specify the build context, but now it allows you to simplify the Dockerfile and choose a more specific build context instead of using the entire repository (like in your case). I might have missed something while implementing it. It looks like it doesn't handle backward compatibility properly 😐.

[alexaka1]

This also does not work:
var folder = $"{Path.GetDirectoryName(data.Dockerfile)}/"; (added trailing slash manually)

~~exception:~~

Docker.DotNet.DockerApiException: Docker API responded with status code=NotFound, response={"message":"pull access denied for distroless-dotnet-health...

Docker.DotNet.DockerApiException
Docker API responded with status code=NotFound, response={"message":"pull access denied for distroless-dotnet-healthchecks, repository does not exist or may require 'docker login'"}

   at Docker.DotNet.DockerClient.HandleIfErrorResponseAsync(HttpStatusCode statusCode, HttpResponseMessage response) in /_/src/Docker.DotNet/DockerClient.cs:line 516
   at Docker.DotNet.DockerClient.MakeRequestForRawResponseAsync(HttpMethod method, String path, IQueryString queryString, IRequestContent body, IDictionary`2 headers, CancellationToken token) in /_/src/Docker.DotNet/DockerClient.cs:line 331
   at Docker.DotNet.Models.StreamUtil.MonitorResponseForMessagesAsync[T](Task`1 responseTask, DockerClient client, CancellationToken cancel, IProgress`1 progress) in /_/src/Docker.DotNet/Endpoints/StreamUtil.cs:line 80
   at DotNet.Testcontainers.Clients.DockerImageOperations.CreateAsync(IImage image, IDockerRegistryAuthenticationConfiguration dockerRegistryAuthConfig, CancellationToken ct) in /_/src/Testcontainers/Clients/DockerImageOperations.cs:line 73
   at DotNet.Testcontainers.Clients.TestcontainersClient.PullImageAsync(IImage image, CancellationToken ct) in /_/src/Testcontainers/Clients/TestcontainersClient.cs:line 430
   at DotNet.Testcontainers.Clients.TestcontainersClient.BuildAsync(IImageFromDockerfileConfiguration configuration, CancellationToken ct) in /_/src/Testcontainers/Clients/TestcontainersClient.cs:line 395
   at DotNet.Testcontainers.Images.FutureDockerImage.UnsafeCreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 145
   at DotNet.Testcontainers.Images.FutureDockerImage.CreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 112
   at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Init(TestData data, CancellationToken cancellationToken) in /Users/alexaka1/git/personal/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 101
   at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Container_is_healthy(String image, String runtimeTag, String targetFramework, String dockerfile) in /Users/alexaka1/git/personal/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 46
   at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Container_is_healthy(String image, String runtimeTag, String targetFramework, String dockerfile) in /Users/alexaka1/git/personal/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 62
   at Xunit.v3.TestRunner`2.<>c__DisplayClass5_0.<<InvokeTest>b__1>d.MoveNext() in /_/src/xunit.v3.core/Runners/TestRunner.cs:line 170
--- End of stack trace from previous location ---
   at Xunit.v3.ExceptionAggregator.RunAsync(Func`1 code) in /_/src/xunit.v3.core/Exceptions/ExceptionAggregator.cs:line 124



Docker.DotNet.DockerApiException: Docker API responded with status code=NotFound, response={"message":"pull access denied for distroless-dotnet-healthchecks, repository does not exist or may require 'docker login'"}

   at Docker.DotNet.DockerClient.HandleIfErrorResponseAsync(HttpStatusCode statusCode, HttpResponseMessage response) in /_/src/Docker.DotNet/DockerClient.cs:line 516
   at Docker.DotNet.DockerClient.MakeRequestForRawResponseAsync(HttpMethod method, String path, IQueryString queryString, IRequestContent body, IDictionary`2 headers, CancellationToken token) in /_/src/Docker.DotNet/DockerClient.cs:line 331
   at Docker.DotNet.Models.StreamUtil.MonitorResponseForMessagesAsync[T](Task`1 responseTask, DockerClient client, CancellationToken cancel, IProgress`1 progress) in /_/src/Docker.DotNet/Endpoints/StreamUtil.cs:line 80
   at DotNet.Testcontainers.Clients.DockerImageOperations.CreateAsync(IImage image, IDockerRegistryAuthenticationConfiguration dockerRegistryAuthConfig, CancellationToken ct) in /_/src/Testcontainers/Clients/DockerImageOperations.cs:line 73
   at DotNet.Testcontainers.Clients.TestcontainersClient.PullImageAsync(IImage image, CancellationToken ct) in /_/src/Testcontainers/Clients/TestcontainersClient.cs:line 430
   at DotNet.Testcontainers.Clients.TestcontainersClient.BuildAsync(IImageFromDockerfileConfiguration configuration, CancellationToken ct) in /_/src/Testcontainers/Clients/TestcontainersClient.cs:line 395
   at DotNet.Testcontainers.Images.FutureDockerImage.UnsafeCreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 145
   at DotNet.Testcontainers.Images.FutureDockerImage.CreateAsync(CancellationToken ct) in /_/src/Testcontainers/Images/FutureDockerImage.cs:line 112
   at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Init(TestData data, CancellationToken cancellationToken) in /Users/alexaka1/git/personal/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 101
   at Distroless.HealthChecks.Test.HealthyTests.HealthyContainerTest`1.Container_is_healthy(String image, String runtimeTag, String targetFramework, String dockerfile) in /Users/alexaka1/git/personal/distroless-dotnet-healthchecks/test/Distroless.HealthChecks.Test/HealthyTests/HealthyContainerTest.cs:line 46

[alexaka1]

Yes, this is a new API.

I like the concept. Although I got very used to just assuming everything is from the root context, but I will remember to use it in the future.

[HofmeisterAn]

This does not work:

This also does not work: var folder = $"{Path.GetDirectoryName(data.Dockerfile)}/"; (added trailing slash manually)

exception:

I ran the configuration above, and it's working on my environment. It seems like the error is due to distroless-dotnet-healthchecks:test being missing. Did you build it before running the tests?

[alexaka1]

I ran the configuration above, and it's working on my environment. It seems like the error is due to distroless-dotnet-healthchecks:test being missing. Did you build it before running the tests?

I should read my own readme 🙈 I totally forgot to build the image first. It is working.

[HofmeisterAn]

I ran the configuration above, and it's working on my environment. It seems like the error is due to distroless-dotnet-healthchecks:test being missing. Did you build it before running the tests?

I should read my own readme 🙈 I totally forgot to build the image first. It is working.

In the previous version, Testcontainers couldn't resolve ARGs like this. Now, these ARGs are resolved, and it expects that the image exists locally to successfully run the build (#1532; if not, it tries to pull the image). TBH I don't know what happened here in previous versions. I would have expected it to fail too.

[HofmeisterAn]

I ran the configuration above, and it's working on my environment. It seems like the error is due to distroless-dotnet-healthchecks:test being missing. Did you build it before running the tests?

I should read my own readme 🙈 I totally forgot to build the image first. It is working.

Okay, then I need to figure out what causes the regression and fix/document it. Thanks for creating the issue!

[alexaka1]

In the previous version, Testcontainers couldn't resolve ARGs like this. Now, these ARGs are resolved, and it expects that the image exists locally to successfully run the build (#1532; if not, it tries to pull the image). TBH I don't know what happened here in previous versions. I would have expected it to fail too.

It most definitely worked since 11 months ago: https://github.com/alexaka1/distroless-dotnet-healthchecks/blob/d094fdce5651f4bb038ee1b9879d300ce0555bf7/test/Distroless.Sample.WebApp/chiseled.Dockerfile

It was very painful to make it work, you may remember my rant from Twitter, it was for this project partly. But it did work, and have worked since. The line you linked was added in late august, so that also worked since then, and renovate updates the deps, so it was working as late as 4.7.0.

[HofmeisterAn]

Yes, I remember. Unfortunately, the cool build features aren't available through the Docker Engine API, so ImageFromDockerfileBuilder didn't get much attention in the past.

In version 4.8.0, I made some improvements and added support for more use cases. I've tried to keep things backward-compatible. One big improvement is support for Docker build contexts like in the Docker CLI, which should reduce extra config and setup.

[KrustyLeBot]

In the previous version, Testcontainers couldn't resolve ARGs like this. Now, these ARGs are resolved, and it expects that the image exists locally to successfully run the build (#1532; if not, it tries to pull the image). TBH I don't know what happened here in previous versions. I would have expected it to fail too.

It most definitely worked since 11 months ago: https://github.com/alexaka1/distroless-dotnet-healthchecks/blob/d094fdce5651f4bb038ee1b9879d300ce0555bf7/test/Distroless.Sample.WebApp/chiseled.Dockerfile

It was very painful to make it work, you may remember my rant from Twitter, it was for this project partly. But it did work, and have worked since. The line you linked was added in late august, so that also worked since then, and renovate updates the deps, so it was working as late as 4.7.0.

I confirm that up until 4.7.0 it worked fine. Unfortunately, I also noticed it break when updating to 4.8.0.