Tranpose a Dockerfile for emulated builds

Using this module as a pre-processor for Dockerfiles which will not run on your system natively, along with a version of qemu-linux-user suitable for emulation, will produce a Dockerfile which will run seamlessly.

Usage

docker-qemu-transpose has a simple API, with two main functions;

• tranpose(dockerfile: string, options: TranposeOptions): string

Given a Dockerfile and tranpose options, produce a Dockerfile which will run on the same architecture as the qemu provided in options (detailed below).

• transposeTarStream(tarStream: ReadableStream, options: TransposeOptions, dockerfileName = 'Dockerfile'): Promise<ReadableStream>

Given a tar archive stream, this function will extract the Dockerfile (or file named with the given dockerfileName parameter) and transpose it. It then creates a new tar stream, and returns it wrapped in a bluebird Promise.

• getBuildThroughStream(options: TransposeOptions): ReadWriteStream

Get a through stream, which when piped to will remove all extra output that is added as a result of this module transposing a Dockerfile.

This function enables 'silent' emulated builds, with the only difference in output from a native build being that there is an extra COPY step, where the emulator is added to the container

Options

• TranposeOptions is an interface with two required fields;
  • hostQemu - The location of the qemu binary on the host filesystem
  • containerQemu - Where qemu should live on the built container

Notes

A version of qemu with execve support is required, which can be retrieved from https://github.com/resin-io/qemu.