Question

我有一个Dockerfile字符串_dockerfile，用作生成其他Dockerfile的模板。我正在尝试使用生成的模板_dockerfile字符串并将其打包在内存中，作为Docker API的流。 Docker守护程序要求流是/build端点上的documentation的tar流：

输入流必须是使用以下算法之一压缩的tar归档文件：身份（无压缩），gzip，bzip2，xz

我目前正在使用SharpZipLib库来构建它：

public async Task BuildAsync() {
    using (var inputMs = new MemoryStream(Encoding.ASCII.GetBytes(_dockerfile))) {

        var outputMs = new MemoryStream() as Stream;

        // Docker.DotNet.DockerClient.BuildImageFromDockerfileAsync requires a Stream in order to send it to the Docker daemon.
        var builderStream = await _client.Images.BuildImageFromDockerfileAsync(CreateContext(inputMs, outputMs), new ImageBuildParameters() { Dockerfile = ".", Tags = new string[] { "test/test:latest" } });

        using (var sr = new StreamReader(builderStream)) {
            while (sr.Peek() > -1) {
                var output = await sr.ReadLineAsync();
                Console.WriteLine(output);
            }
        }
    }
}

private Stream CreateContext(Stream input, Stream output) {
    var tarOutputStream = new TarOutputStream(output);
    var entry = TarEntry.CreateTarEntry("Dockerfile");
    entry.Size = input.Length;
    tarOutputStream.PutNextEntry(entry);

    // read from the input stream, write to the local buffer,
    // then write to the file.
    var buffer = new byte[32 * 1024];
    while (true) {
        int numRead = input.Read(buffer, 0, buffer.Length);
        if (numRead <= 0)
            break;
        tarOutputStream.Write(buffer, 0, numRead);
    }

    tarOutputStream.CloseEntry();
    return tarOutputStream;
}

当我运行它时，出现此错误：

Docker.DotNet.DockerApiException: Docker API responded with status code=InternalServerError, response={"message":"unexpected error reading Dockerfile: read /var/lib/docker/tmp/docker-builder534485209: is a directory"}

我认为发生的事情是因为我尚未关闭tar存档流，而是试图从守护程序的内存中读取？无论哪种方式，我都知道我必须更好地处理流管道。

如何在不写入磁盘的情况下将内存中的字符串转换为tar流？

将tar文件流式传输到Docker.DotNet库吗？

0 个答案: