Continuous integration


GitHub Actions are configured to build master and develop branches and pull requests.

GitHub Actions build Roc for Linux and macOS. Linux worker uses Docker to run builds on several Linux distros. Linux worker also uses QEMU to run cross-compiled tests.

Docker images for continuous integration and cross-compilation are prepared using Docker Hub automated builds. They are based on official upstream images, adding pre-installed packages required for build. Dockerfiles for images are hosted in a separate GitHub repository. When a Dockerfile or an upstream image changes, Docker Hub automatically triggers rebuild.

If images build have to be customized with build arguments it can be accomplished by using build hooks.


Docker images

The following Docker images are used on our CI builds.

Linux native

Image Base image Architecture Compilers
rocstreaming/env-ubuntu:22.04 ubuntu:22.04 x86_64 gcc-11, gcc-12, clang-11, clang-14
rocstreaming/env-ubuntu:20.04 ubuntu:20.04 x86_64 gcc-8, gcc-10, clang-8, clang-10
rocstreaming/env-ubuntu:18.04 ubuntu:18.04 x86_64 gcc-6, clang-6
rocstreaming/env-ubuntu:16.04 ubuntu:16.04 x86_64 gcc-4.8, clang-3.7
rocstreaming/env-ubuntu:14.04 ubuntu:14.04 x86_64 gcc-4.4, clang-3.4
rocstreaming/env-ubuntu-minimal ubuntu:latest x86_64 distro default
rocstreaming/env-debian debian:stable x86_64 distro default
rocstreaming/env-fedora fedora:latest x86_64 distro default
rocstreaming/env-centos centos:latest x86_64 distro default
rocstreaming/env-opensuse opensuse/leap:latest x86_64 distro default
rocstreaming/env-archlinux archlinux/base:latest x86_64 distro default
rocstreaming/env-alpine alpine:latest x86_64 distro default

Linux toolchains

Image Architecture Compilers
rocstreaming/toolchain-aarch64-linux-gnu:gcc-7.4 armv8 gcc-7.4
rocstreaming/toolchain-arm-linux-gnueabihf:gcc-4.9 armv7 gcc-4.9
rocstreaming/toolchain-arm-bcm2708hardfp-linux-gnueabi:gcc-4.7 armv6 gcc-4.7

Android toolchains

Image APIs ABIs Compilers
rocstreaming/toolchain-linux-android:ndk21 21-29 armeabi-v7a, arm64-v8a, x86, x86_64 clang-9.0.8

Full Android environment

Image JDK
rocstreaming/env-android:jdk11 openjdk:11.0.7-jdk-slim-buster
rocstreaming/env-android:jdk8 openjdk:8u252-jdk-slim-buster

Running CI builds locally

It is possible to run Docker-based builds locally, in the same environment as they are run on CI.

For example, this will run Fedora build:

$ scripts/ci_checks/ rocstreaming/env-fedora \

You can also invoke Docker manually:

$ docker run -t --rm --cap-add SYS_PTRACE -u "${UID}" -v "${PWD}:${PWD}" -w "${PWD}" \
    rocstreaming/env-fedora \
      scons --build-3rdparty=openfec,cpputest --enable-debug test


  • -t allocates a pseudo-TTY to enable color output
  • --rm removes the container when the command exits
  • --cap-add SYS_PTRACE enables ptracing which is needed for clang sanitizers
  • -u "${UID}" changes the UID inside the container from root to the current user
  • -v "${PWD}:${PWD}" mounts the current directory into the container at the same path
  • -w "${PWD}" chdirs into that directory

Working with Docker images

Docker images are built using GitHub actions and then pushed to Docker Hub.

Each image directory contains one or several dockerfiles and images.csv file in the following format:

DOCKERFILE;ARGS (comma-separated list);TAG

This file defines what tags to build, path to dockerfile and build arguments for each tag. Build arguments are passed as ARGs to docker build.

If the value in the first column is left empty, it defaults to Dockerfile is in the same directory as images.csv. If the value in the last column is omitted, it defaults to the name of the directory which contains Dockerfile, e.g. if Dockerfile path is 14.04/Dockerfile, then tag defaults to 14.04.


DOCKERFILE;ARGS (comma-separated list);TAG

This file defines three tags: gcc-4.9, gcc-7.4, and latest. Each tag uses the same Dockerfile and different arguments MAJOR, MINOR, and DATE.

You can build all docker images locally using:

./scripts/ --build

Or build specific image:

cd images/<image_name>

Android environment

The env-android images provide a full android environment. In particular the following packages are availables:

  • android platforms
  • android build tools
  • android ndk
  • android cmake
  • android emulator
  • adb and platform tools

For reducing image size and have more granularity over various tools versions, those packages are installed only when container runs, i.e. at container entrypoint.

The following environment variables can be passed at container run for choosing a specified version:

  • API


$ docker run -t --rm -v "${PWD}:${PWD}" -w "${PWD}" -v android-sdk:/sdk --env API=28 \
  --env NDK_VERSION=21.1.6352462 --env BUILD_TOOLS_VERSION=29.0.3 \
    rocstreaming/env-android:jdk8 \
      scons -Q --compiler=clang --host=aarch64-linux-android28 \
        --disable-soversion \
        --disable-tools \
        --disable-examples \
        --disable-tests \
        --disable-pulseaudio \
        --disable-sox \

Tools caching

If a named volume is mounted at /sdk path in the container (for example by using -v android-sdk:/sdk option), next run of the image will not install again components already installed previously.

If it’s needed to mount the volume to a specific host location (the host location must exist) it can be achieved by adding the following options to the docker command:

--mount type=volume,dst=/sdk,volume-driver=local,volume-opt=type=none,volume-opt=o=bind,volume-opt=device=<host-path>


The android emulator can use hardware acceleration features to improve performance, sometimes drastically.


According to official emulator acceleration docs:

To use VM acceleration, your development environment must meet the following requirements:

SDK Tools: minimum version 17; recommended version 26.1.1 or later AVD with an x86-based system image, available for Android 2.3.3 (API level 10) and higher

Warning: AVDs that use ARM- or MIPS-based system images can’t use the VM acceleration.

In addition to the development environment requirements, your computer’s processor must support one of the following virtualization extensions technologies:

Intel Virtualization Technology (VT, VT-x, vmx) extensions AMD Virtualization (AMD-V, SVM) extensions

Linux-based systems support VM acceleration through the KVM software package.

For enabling hardware acceleration run the container in privileged mode, i.e. by using --privileged flag.


Since CI runs jobs already on a virtual environment, if the emulator need to be run on CI, the env-android image must be run with --privileged option for allowing virtualization nesting.

To see if acceleration is available use:

$ emulator -accel-check
KVM (version 12) is installed and usable.

To create an Android Virtual Device (AVD) and run the emulator:

  • download the emulator system image:

    $ yes | sdkmanager <system-image>

    where <system-image> is in the list offered by sdkmanager --list

  • create the AVD:

    $ echo no | avdmanager create avd --name <avd-name> --package <system-image>
  • launch emulator (use -accel on or -accel off depending of hardware acceleration availability):

    $ emulator -avd <avd-name> -no-audio -no-boot-anim -no-window -gpu off -accel [on/off] &
  • check the AVD status:

    $ adb devices
    List of devices attached
    emulator-xxxx device
    # "device" indicates that boot is completed
    # "offline" indicates that boot is still going on

Device script

The env-android image provides an helper script named device that takes care of creating and booting up AVDs.

  • create an AVD:

    $ device create --api=<API> --image=<IMAGE> --arch=<ARCH> --name=<AVD-NAME>

    The string "system-images;android-<API>;<IMAGE>;<ARCH>" defines the emulator system image to be installed (it must be present in the list offered by sdkmanager --list)

  • start device and wait until boot is completed

    $ device start --name=<AVD-NAME>