build-multipath - helpers for multipath-tools CI

Scripts and helpers for building multipath-tools and running the CI. Work in progress.

License

Copyright (c) 2021 Martin Wilck, SUSE LLC

All files in this project are licensed under the GNU General Public License v2.0, or any later version. THE CODE IS PROVIDED WITHOUT WARRANTY OF ANY KIND. Refer to the license text for details.

Purpose

Dockerfile generation

Generate Dockerfiles for creating build environments for compiling multipath-tools. The Dockerfiles are generated with m4. Currently supported distributions:

• Alpine
• Arch
• Centos (7, 8)
• Debian (jessie, buster, bullseye, sid)
• Fedora
• openSUSE Leap, Tumbleweed, SUSE Linux Enterprise Server
• Ubuntu

These distributions are supported for multiple architectures. For Debian, cross-compilation environments are supported too.

Using m4

The m4 command line for creating a Dockerfile looks as follows:

m4 -I m4 -D DISTRO=$dist header.m4 dockerfile.m4

The DISTRO argument has the format $distribution[-$release[-$tag]]. The "release" is a variant of the distribution and the "tag" is the docker registry tag to be used to pull the base image. The conventions vary between distributions, but the code has helpful defaults. Valid DISTRO values are e.g.:

• alpine, arch
• debian-buster, debian-sid
• centos-8
• ubuntu-focal
• opensuse-leap-15.3 (note specific tag), opensuse-leap, opensuse-tumbleweed
• sles-15, sles-15-15.4, sles-12
• fedora-rawhide, fedora-36
• debian_cross-bullseye (this is debian for cross-compilation)

To create a Dockerfile for the runtime environment, use runnerfile.m4:

m4 -I m4 -D DISTRO=debian-bullseye header.m4 runnerfile.m4

Optionally, you can also set -D PACKAGE=multipath. This might matter in the future if additional packages besides multipath-tools are supported. Currently it defaults to multipath.

For SLES, the created dockerfiles use secrets that have to be passed on the docker command line. SLES builds support an option argument -D TYPE=obs which creates a Dockerfile suitable for building in the OpenSUSE Build Service (OBS).

Additional packages can be included in the build container using -DADD_PKGS=$package.

Container generation

Containers are generated from the Dockerfiles created above using GitHub workflows. The built packages are available from ghcr.io.

• multipath-build-$DISTRIBUTION[-$RELEASE]: Containers for building and running the unit tests.
• multipath-cross-debian_cross-$RELEASE-$ARCH: Cross-compilation environment. For non-native architectures, cross compilation is much faster than running in an emulator environment.
• multipath-run-debian-$RELEASE: Runtime environment to test the cross-compiled binaries.

The build and cross-build containers expect the multipath-tools source directory to be mounted under /build. They use make as entrypoint. To compile multipath-tools and run the unit tests, run e.g.

docker run --platform linux/arm64 -it --rm -v $PWD:/build \
    ghcr.io/mwilck/multipath-build-centos-8 -j test

(Note that for running non-native containers, you'll have to install the qemu-user package on your distribution. See e.g. qemu-user-static).

To use cross compilation:

docker run -it --rm -v $PWD:/build \
    ghcr.io/mwilck/multipath-cross-debian_cross-sid-s390x -j test-progs
docker run --platform linux/s390x -it --rm -v $PWD:/build \
    ghrc.io/mwilck/multipath-run-debian-sid test

Note that the test-progs target is used for the build step.

Old content (deprecated)

Containers (docker, podman)

Run all commands below in the Docker subdirectory. Both podman and docker container runtimes are supported.

Basic usage:

make MPATH_DIR=/my/multipath-tools/dir TARGET=alpine

This will create the docker image for testing under the given distribution (here: alpine linux), build multipath-tools from the given directory, and run the unit tests (only those that don't require block devices, because they can't be run in containers).

Subsequent make invocations can be done without setting MPATH_DIR and TARGET; they will be remembered.

MPATH_DIR should be a directory containing the multipath-tools sources, such as a checked-out mirror of the multipath-tools repository. The directory will be mounted into the container, and will be written to using comands like make and make clean.

make targets

• test: build and run unit tests. This is the default target.
• test-progs: build libraries, commands, and unit tests, but don't run the tests.
• img: build the docker image.
• build: build multipath-tools.
• install: run make install. DESTDIR must be set when invoked.
• clean: run make clean.
• img-clean: run make clean, and forget current settings.
• purge: remove current image from local docker storage.

Furthermore, every defined "make" target from the multipath-tools Makefile can be built by prepending it with m-; e.g. make m-tests.clean runs make tests.clean in the container (this is useful if you want to re-run the tests).

Note: Makefile logic tries to ensure that if TARGET is changed, the complete sources are rebuilt. But sometimes this fails. In this case, running make clean; make usually fixes the issue.

Environment variables for building

To override build variables like CC or OPTFLAGS in the container, you have to set the environment variable BUILDFLAGS on the host:

make 'BUILFLAGS="CC=clang OPTFLAGS="-O0 -g"'

Using locally built containers

Unless TARGET starts with "registry." or "docker.io", it must be the name of a subdirectory of Docker, usually a nickname of a distribution, containing a Dockerfile. The Dockerfile should create an environment suitable for building multipath-tools. See existing Dockerfiles for examples. The built container image will be called multipath-build-$TARGET.

Using containers from a registry

If the TARGET name starts with registry. or docker.io/, building the container image will not be attempted. Rather, the given image will be pulled from a registry. Example:

TARGET=registry.suse.de/some/project/images/sle-15-sp1/containers/multipath-build
TARGET=docker.io/mwilck/multipath-build-alpine

Note that multipath build will fail if the downloaded containers don't include all necessary dependencies.

Note on SUSE Linux Enterprise (SLE) containers

Building these containers requires a valid SLE subscription. If in doubt, check your licensing conditions to figure out if you are entitled to build and run SLE containers in this way.

Building the images requires features that are only available in recent docker versions. Before running make, set the environment variable DOCKER_BUILDKIT=1, otherwise the image build will fail. See the documentation about building SLE containers.

On a registered SLE host, building the images should just work. In other environments, valid credentials must be pulled in from elsewhere. Copy the files /etc/zypp/credentials.d/SCCcredentials and /etc/SUSEConnect from a registered SLE system into the respective subdirectory before building the image. The registered system must have the required additional modules enabled (see the distribution's Dockerfile).

Foreign architectures (ppc64le, aarch64, s390x)

The containers in this repository are designed to be run on Intel-compatible platforms (x86_64 architecture). For some distributions, other architectures are supported as well. In this case, the unit tests are run in a special container called multipath-run-$os-$arch. This container is built from another Dockerfile stored under $(TARGET)/Runner. The container includes an emulator (usually qemu-user-static for emulating the target architecture), and is otherwise a native environment for the target architecture including the run-time dependencies for multipath-tools. Currently, containers built this way are not used for the build process itself, only for running the tests. The build containers use cross-compilation instead, utilizig Debian's multiarch cross-compilation features.