Example of using BuildImageFromDockerfileAsync

[andtii]

Im trying to use the BuildImageFromDockerfileAsync but i get an error response stating unexpected EOF. I cant find any examples of how to use it.

[edmBernard]

I was not able to make it work. It seem you need to create an archive (tar.gz) file from your context. and send it in the stream argument.

https://forums.docker.com/t/how-to-build-an-image-using-docker-api/31807

using (var stream = new FileStream(@"context.tar.gz", FileMode.Open))
{
    var task = client.Images.BuildImageFromDockerfileAsync(stream, new ImageBuildParameters() { Dockerfile = "path/to/your dockerfile/inside your tar file", Tags = new string[] { "foo:latest" } });
    task.Wait();
}

[edmBernard]

I try something like that but it still crash

DockerClient client = new DockerClientConfiguration(new Uri("unix:///var/run/docker.sock")).CreateClient();

var tarPath = System.IO.Path.GetTempPath() + "context.tar.gz";
if (File.Exists(tarPath))
{
    File.Delete(tarPath);
}
ZipFile.CreateFromDirectory(".", tarPath);
Console.WriteLine(tarPath);
foreach (var service in serviceImage.Keys)
{
    // var stream = File.OpenRead(serviceDockerfile[service]);
    using (var stream = new FileStream(tarPath, FileMode.Open))
    {
        var task = client.Images.BuildImageFromDockerfileAsync(stream, new ImageBuildParameters() { Dockerfile = serviceDockerfile[service], Tags = new string[] { serviceImage[service] } });
        task.Wait();
    }
}

Unhandled Exception: System.AggregateException: One or more errors occurred. (The requested failed, see inner exception for details.) ---> System.Net.Http.HttpRequestException: The requested failed, see inner exception for details. ---> System.Net.Http.HttpRequestException: Error while copying content to a stream.---> System.IO.IOException: Unable to transfer data on the transport connection: Broken pipe. ---> System.Net.Sockets.SocketException: Broken pipe
   --- End of inner exception stack trace ---

[edmBernard]

I found my mistake Docker API accept a .tar file not a .tar.gz If you create your context with tar -zcvf /tmp/context.tar . and use the following code it works for me :

DockerClient client = new DockerClientConfiguration(new Uri("unix:///var/run/docker.sock")).CreateClient();

var tarPath = System.IO.Path.GetTempPath() + "context.tar";
Console.WriteLine(tarPath);
foreach (var service in serviceImage.Keys)
{
    using (var stream = new FileStream(tarPath, FileMode.Open))
    {
        var task = client.Images.BuildImageFromDockerfileAsync(stream, new ImageBuildParameters() { Dockerfile = serviceDockerfile[service], Tags = new string[] { serviceImage[service] } });
        task.Wait();
    }
}

[omniscient]

I could never make this work on Windows... This method complexity is too high and should be refactored to avoid passing in a TAR stream. I ended up using a process to accomplish it:

        public void Build(string targetName, string pathToDockerFile)
        {
            try
            {
                var process = new Process();
                var startInfo = new ProcessStartInfo
                {
                    WindowStyle = ProcessWindowStyle.Hidden,
                    FileName = "cmd.exe",
                    Arguments = $"/C docker build -t {targetName} -f {pathToDockerFile}/Dockerfile {pathToDockerFile}"
                };
                process.StartInfo = startInfo;
                process.Start();
                process.WaitForExit();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
            }
        }

[Serg046]

Yes, why not to set a context as usual. Docker engine can copy the files without our interaction.

[KyleGobel]

The command worked fine for me on Windows.

One thing I did stumble upon:

When creating the tar file (using SharpZipLib) if I create the tar entries from the filenames, the tar will be created with the wrong slashes (\ instead of / for linux). I had to swap those out myself if you're doing any COPY or ADD within folders.

Psuedo-code but here's all there is to build a docker image

var tarFilePath = CreateTarFile(); // contains Dockerfile, and then some content within folders, uncompressed
var stream = File.OpenRead(tarFilePath);

var response = await client.BuildImageFromDockerfileAsync(stream, new ImageBuildParameters 
{ 
   Tags = new List<string> { "my-image" }
});

I'm guessing the tricky part is probably creating the tar file.

• This acts as your docker context, so make sure a Dockerfile is in there, and if it's not named Dockerfile then make sure to update the ImageBuildParameters with where it's at.
• Watch for the wrong slashes on windows

[MorenoGentili]

I can confirm it's working on Docker Desktop for Windows 10. This is the code I used to create the tarball. It's using SharpZipLib as kindly pointed out by @KyleGobel.

private static Stream CreateTarballForDockerfileDirectory(string directory)
{
    var tarball = new MemoryStream();
    var files = Directory.GetFiles(directory, "*.*", SearchOption.AllDirectories);

    using var archive = new TarOutputStream(tarball)
    {
        //Prevent the TarOutputStream from closing the underlying memory stream when done
        IsStreamOwner = false
    };

    foreach (var file in files)
    {
        //Replacing slashes as KyleGobel suggested and removing leading /
        string tarName = file.Substring(directory.Length).Replace('\\', '/').TrimStart('/');
		
        //Let's create the entry header
        var entry = TarEntry.CreateTarEntry(tarName);
        using var fileStream = File.OpenRead(file);
        entry.Size = fileStream.Length;
        archive.PutNextEntry(entry);

        //Now write the bytes of data
        byte[] localBuffer = new byte[32 * 1024];
        while (true)
        {   
            int numRead = fileStream.Read(localBuffer, 0, localBuffer.Length);
            if (numRead <= 0)
                break;

            archive.Write(localBuffer, 0, numRead);
        }
		
        //Nothing more to do with this entry
        archive.CloseEntry();
    }
    archive.Close();

    //Reset the stream and return it, so it can be used by the caller
    tarball.Position = 0;
    return tarball;
}

Remeber to dispose the tarball Stream after you've sent it via BuildImageFromDockerfileAsync. Here's a usage example:

var imageBuildParameters = new ImageBuildParameters
{
    //...
};
//C# 8.0 using syntax
using var tarball = CreateTarballForDockerfileDirectory(workingDirectory);
using var dockerClient = new DockerClientConfiguration(new Uri("npipe://./pipe/docker_engine")).CreateClient();
using var responseStream = await dockerClient.Images.BuildImageFromDockerfileAsync(tarball, imageBuildParameters);

[shelly-rng]

The command above was almost working the same has the command line, the mode file must be set for each file in the tarball archive, like this:

entry.Size = fileStream.Length;
entry.TarHeader.Mode = Convert.ToInt32("100755", 8); //chmod 755
archive.PutNextEntry(entry);

[davidguidali]

Would be good if this was supported out of the box.

[EugeneKrapivin]

wow, I'm in 2024 and still no real solution for this. @MorenoGentili awesome answer :) did you ever extend this to support the dockerignore file?

[HofmeisterAn]

In Testcontainers for .NET, we use the following implementation to build an image. Testcontainers contains many features like this that should ideally be part of the Docker client. That's why I recently forked the project. I would like to move more features from Testcontainers to the client so that more developers can benefit from them. If someone wants to contribute and work on such a feature (or migration), I would be happy to review it and include it in the forked version.