[Enhancement]: Better method for sending multiple files to the conainer

[dgiddins]

Problem

.WithResourceMapping() Allows us to send files to the container. When there are many files to be sent calling StartAsync() on the container can timeout. Probably as files are sent in parallel

testcontainers-dotnet/src/Testcontainers/Clients/TestcontainersClient.cs

Lines 294 to 298 in 6688b92

	if (configuration.ResourceMappings != null)
	{
	await Task.WhenAll(configuration.ResourceMappings.Values.Select(resourceMapping => CopyResourceMapping(id, resourceMapping)))
	.ConfigureAwait(false);
	}

Solution

To allow sending of archives that are then automatically unzipped in the container. Or this could be implemented as providing a list of files to the container builder so that the builder creates the archive and then unzips into a specified target directory.

testcontainers-dotnet/src/Testcontainers/Clients/TestcontainersClient.cs

Lines 166 to 206 in 6688b92

	public async Task CopyFileAsync(string id, string filePath, byte[] fileContent, int accessMode, int userId, int groupId, CancellationToken ct = default)
	{
	IOperatingSystem os = new Unix(dockerEndpointAuthConfig: null);
	var containerPath = os.NormalizePath(filePath);
	using (var tarOutputMemStream = new MemoryStream())
	{
	using (var tarOutputStream = new TarOutputStream(tarOutputMemStream, Encoding.Default))
	{
	tarOutputStream.IsStreamOwner = false;
	var header = new TarHeader();
	header.Name = containerPath;
	header.UserId = userId;
	header.GroupId = groupId;
	header.Mode = accessMode;
	header.Size = fileContent.Length;
	var entry = new TarEntry(header);
	await tarOutputStream.PutNextEntryAsync(entry, ct)
	.ConfigureAwait(false);
	#if NETSTANDARD2_1_OR_GREATER
	await tarOutputStream.WriteAsync(fileContent, ct)
	.ConfigureAwait(false);
	#else
	await tarOutputStream.WriteAsync(fileContent, 0, fileContent.Length, ct)
	.ConfigureAwait(false);
	#endif
	await tarOutputStream.CloseEntryAsync(ct)
	.ConfigureAwait(false);
	}
	tarOutputMemStream.Seek(0, SeekOrigin.Begin);
	await this.containers.ExtractArchiveToContainerAsync(id, Path.AltDirectorySeparatorChar.ToString(), tarOutputMemStream, ct)
	.ConfigureAwait(false);
	}
	}

Benefit

When using sqitch for managing changes to database schemas the schema repo can grow very large resulting in many files needing to be moved.

Alternatives

Using volume mounts which is not advised.

Would you like to help contributing this enhancement?

Yes

[HofmeisterAn]

To create a Docker image, a lot of similar code is necessary. I think we can reuse and restructure a lot. This part implements ITarArchive to create a tarball of the Docker image build context, which includes all files and subdirectories of a directory.

I believe we need to overload CopyFileAsync with a source and target paths and determine whether the source path is a directory or not. Based on the FileSystemInfo, we can construct the tarball and pass it to the Docker endpoint.