MultiArch Alpine Linux + S6 + Python3 + Buildbot (Master)
This image serves as the base container for running a Buildbotmaster instance to build applications, run periodic tasks, and other automations. Checkout their docs for configurations or task definitions. Also, checkout the alpine-buildworker image for running a standalone worker as a service.
latest tag is annotated as multiarch so pulling without specifying any architecture tags should fetch the correct image for your architecture. Same goes for any of the version tags.
non-x86_64 images used to contain the embedded qemu-user-static binary which has been redundant for a while, and is being deprecated starting with our Alpine Linux v3.22 base-image release, see qemu-user-static or the more recent binfmt instead for running multi-arch containers.
If you want to run images built for other architectures on the same host (e.g. a x86_64 machine), you will need to have the specific binary format support configured on your host machine before running the image (otherwise you get an exec format error). Here's how,
For recent images, we can use tonistiigi's binfmtimage to register binary execution support for the target architecture, like the following,
However, that image (see qemu-user-static) seems to have fallen behind in updates, and with newer images the binfmt method is preferable.
Now images built for other architectures will also be executable. This is optional though, without the above, you can still run the image that is specifically made to support your host architecture.
Skips master setup tasks, useful when your already have your configurations setup, or would like to do it manually.
BUILDBOT_MASTERNAME
${BUILDBOT_PROJECTNAME}-master
Name of the service, defaults to projectname-rolename.
BUILDBOT_MASTERCFG
${BUILDBOT_MASTERNAME}/master.cfg.sample
Path to custom configuration file that is copied into place as master.cfg before starting service.
BUILDBOT_USE_CUSTOM_TACFILE
unset
Whether to use custom tacfile provided in the image that logs to stdout by default, set to a non-empty string (e.g 1) to enable, or use the one generated by package.
Customizable path to tacfile provided in the image.
BUILDBOT_BASEDIR
unset
Used in the custom tacfile to determine where builder files are stored, defaults to "." when unset (current directory where buildbot.tac exists), or any other directory (must exist).
BUILDBOT_LOGDEST
stdout
Used in the custom tacfile to determine where logs are sent, can be either of stdout (default), syslog, or file.
BUILDBOT_LOGROTATE_LENGTH
5000
Used in the custom tacfile to determine maximum lines-in-logfile before it is rotated.
BUILDBOT_LOGROTATE_MAXFILES
2
Used in the custom tacfile to determine maximum rotated logfiles that are kept in storage.
BUILDBOT_CONFIG_URL
unset
If set, tries to fetch configuration from remote location. Can be a tar.gz file, or a git repository, or a file link to master.cfg itself.
BUILDBOT_CONFIG_DIR
${BUILDBOT_HOME}/config
Configurations fetched from remote location unpacked in this directory.
BUILDBOT_CONFIG_TMP
${BUILDBOT_HOME}/.tmp
Configurations fetched from remote location are temporarily stored in this directory. (Useful if /tmp is non-writable or limited space)
BUILDBOT_CONFIG_CFGFILE
master.cfg
Customizable path to master.cfg as relative to downloaded configurations. Default expects at the root of directory, if it exists, it is copied into place as master.cfg before starting service.
BUILDBOT_CONFIG_TACFILE
buildbot.tac
Customizable path to buildbot.tac as relative to downloaded configurations. Default expects at the root of directory, if it exists, it is copied into place as buildbot.tac before starting service.
BUILDBOT_SKIP_CHECKCONFIG
unset
If true. skips checking configurations before starting service.
BUILDBOT_UPGRADE_MASTER
unset
If true, upgrades master database before starting service.
BUILDBOT_CLEANUP_DB
unset
If true, runs cleanup tasks on master database before starting service.
BUILDBOT_WORKERNAME
${BUILDBOT_PROJECTNAME}-worker
Name of the default worker updated in master.cfg. (Only when using the sample configurations)
BUILDBOT_WORKERPASS
insecurebydefault
Password of the default worker updated in master.cfg. (Only when using the sample configurations)
BUILDBOT_SKIP_CUSTOMIZE
unset
Skip post-setup customization tasks.
BUILDBOT_SKIP_PERMFIX
unset
If set to a non-empty-string value (e.g. 1), skip ensuring files in ${BUILDBOT_HOME} are owned by ${S6_USER}, enabled by default.
BUILDBOT_PIDFILE
twistd.pid
If PID file exists from last run, it is removed before starting the service.
BUILDBOT_TACFILE
buildbot.tac
(Preset) The tacfile to use for starting buildbot service.
BUILDBOT_ARGS
--nodaemon --no_save
Customizable arguments passed to master service. (Runs as a twisted application instead of calling buildbot executable)
S6_PIP_PACKAGES
empty string
Space-separated list of packages to install globally with pip.
S6_PIP_REQUIREMENTS
empty string
Path to requirements.txt to install globally with pip.
S6_PIP_USER_PACKAGES
empty string
Space-separated list of packages to install with pip for ${S6_USER}. These are installed in ~/.local/.
S6_PIP_USER_REQUIREMENTS
empty string
Path to requirements.txt to install with pip for ${S6_USER}.
S6_NEEDED_PACKAGES
empty string
Space-separated list of extra APK packages to install on start. E.g. "curl git tzdata"
PUID
1000
Id of ${S6_USER}.
PGID
1000
Group id of ${S6_USER}.
S6_USER
alpine
(Preset) Default non-root user for services to drop privileges to.
S6_USERHOME
/home/alpine
(Preset) HOME directory for ${S6_USER}.
Did you know?
You can check your own UID/GID by running the command id in a terminal.
Also,
The env variable ${BUILDBOT_ROLE} determines if you are running a master or worker. This also determines what image you'll be running when used with the makefile. It is baked into the image so does not need to be changed unless you know what you're doing.
Setup tasks are only run when the buildbot.tac file does not exist or ${BUILDBOT_SKIP_SETUP} is not set. Same goes for arguments / environment variables specific to setup, they are not needed anymore after setup is complete.
However, if ${BUILDBOT_MASTERCFG} is defined, it will always be copied into project before starting the service. This is useful for large projects that maintain the configurations separately from master configurations.
Includes a placeholder script for further customizations before starting processes. Override the shellscript located at /etc/s6-overlay/s6-rc.d/p22-buildbot-customize/run with your custom pre-tasks as needed.
The service does not run buildbot for master, instead calls twistd directly, pass ${BUILDBOT_ARGS} accordingly.
For the master node, mount the configurations at the ${BUILDBOT_HOME} directory inside the container, by default it is /home/alpine/buildbot.
Stop the container with a timeout, (defaults to 2 seconds)
dockerstop-t2docker_buildmaster
Restart the container with
dockerrestartdocker_buildmaster
Removes the container, (always better to stop it first and -f only when needed most)
This snippet can be used to reverse-proxy the service using NGINX.
upstreamproxy_buildmaster{serveryour.host.local:<buildmaster-port>fail_timeout=5;}## the following goes inside a server blocklocation/buildbot/{proxy_passhttp://proxy_buildbot/;}location/buildbot/sse/{# proxy buffering will prevent sse to workproxy_bufferingoff;proxy_passhttp://proxy_buildbot/sse/;}# required for websocketlocation/buildbot/ws{proxy_http_version1.1;proxy_set_headerUpgrade$http_upgrade;proxy_set_headerConnection"upgrade";# raise the proxy timeout for the websocketproxy_read_timeout6000s;proxy_passhttp://proxy_buildbot/ws;}
Feel free to clone (or fork) the repository and customize it for your own usage, build the image for yourself on your own systems, and optionally, push it to your own public (or private) repository.
Before we clone the /repository, we must have Git, GNU make, and Docker (optionally, with buildx plugin for multi-platform images) setup on the machine. Also, for multi-platform annotations, we might require enabling experimental features of Docker.
To create the image for your architecture, run the build and test target with
makebuildtestROLE=master
For building an image that targets another architecture, it is required to specify the ARCH parameter when building. e.g.
makebuildtestARCH=aarch64ROLE=master
makebuildtestARCH=armhfROLE=master
makebuildtestARCH=armv7lROLE=master
makebuildtestARCH=i386ROLE=master
makebuildtestARCH=ppc64leROLE=master
makebuildtestARCH=riscv64ROLE=master
makebuildtestARCH=s390xROLE=master
makebuildtestARCH=x86_64ROLE=master
Build Parameters
All images have a few common build parameters that can be customized at build time, like
ARCH
The target architecture to build for. Defaults to host architecture, auto-detected at build-time if not specified. Also determines if binfmt support is required before build or run and runs the regbinfmt (or inbinfmt for recent images) target automatically. Possible values could be aarch64, armhf, armv7l, or x86_64.
BUILDDATE
The date of the build. Can be used to create separate tags for images. (format: yyyymmdd)
DOCKERFILE
The dockerfile to use for build. Defaults to the file Dockerfile, but if per-arch dockerfiles exist, (e.g. for x86_64 the filename would be Dockerfile_x86_64) that is used instead.
TESTCMD
The command to run for testing the image after build. Runs in a bash shell.
VERSION
The version of the app/tool, may need to be preset before starting the build (e.g. for binaries from github releases), or extracted from the image after build (e.g. for APK or pip packages).
REGISTRY
The registry to push to, defaults to the Docker Hub Registry (docker.io) or any custom registry that is set via docker configurations. Does not need to be changed for local or test builds, but to override, either pass it by setting an environment variable, or with every make command.
ORGNAME
The organization (or user) name under which the image repositories exist, defaults to woahbase. Does not need to be changed for local or test builds, but to override, either pass it by setting an environment variable, or with every make command.
The image may also require custom parameters (like binary architecture). Before you build, check the makefile for a complete list of parameters to see what may (or may not) need to be set.
BuildX and Self-signed certificates
If you're using a private registry (a-la docker distribution server) with self-signed certificates, that fail to validate when pulling/pushing images. You will need to configure buildx to allow insecure access to the registry. This is configured via the config.toml file. A sample is provided in the repository, make sure to replace YOUR.PRIVATE.REGISTRY with your own (include port if needed).
Running the image creates a container and either starts a service (for service images) or provides a shell (can be either a root-shell or usershell) to execute commands in, depending on the image. We can run the image with
makerunROLE=master
But if we just need a root-shell in the container without any fance pre-tasks (e.g. for debug or to test something bespoke), we can run bash in the container with --entrypoint /bin/bash. This is wrapped in the makefile as
makeshellROLE=master
Nothing vs All vs Run vs Shell
By default, if make is run without any arguments, it calls the target all. In our case this is usually mapped to the target run (which in turn may be mapped to shell).
There may be more such targets defined as per the usage of the image. Check the makefile for more information.
If the build and test steps finish without any error, and we want to use the image on other machines, it is the next step push the image we built to a container image repository (like /hub), for that, run the push target with
makepushROLE=master
If the built image targets another architecture then it is required to specify the ARCH parameter when pushing. e.g.
makepushARCH=aarch64ROLE=master
makepushARCH=armhfROLE=master
makepushARCH=armv7lROLE=master
makepushARCH=i386ROLE=master
makepushARCH=ppc64leROLE=master
makepushARCH=riscv64ROLE=master
makepushARCH=s390xROLE=master
makepushARCH=x86_64ROLE=master
Pushing Multiple Tags
With a single make push, we are actually pushing 3 tags of the same image, e.g. for x86_64 architecture, they're namely
alpine-buildmaster:x86_64
The actual image that is built.
alpine-buildmaster:x86_64_${version}
It is expected that the application is versioned when built or packaged, it can be specified in the tag, this makes pulling an image by tag possible. Usually this is obtained from the parameter VERSION, which by default, is set by calling a function to extract the version string from the package installed in the container, or from github releases. Can be skipped with the parameter SKIP_VERSIONTAG to a non-empty string value like 1.
alpine-buildmaster:x86_64_${version}_${builddate}
When building multiple versions of the same image (e.g. for providing fixes or revisions), this ensures that a more recent push does not fully replace a previously pushed image. This way, although the architecture and version tags are replaced, it is possible to roll back to the previously built image by build date (format yyyymmdd). This value is obtained from the BUILDDATE parameter, and if not essential, can be skipped by setting the parameter SKIP_BUILDDATETAG to a non-empty string value like 1.
Pushing To A Private Registry
If you want to push the image to a custom registry that is not pre-configured on your system, you can set the REGISTRY variable either on the build environment, or as a makefile parameter, and that will be used instead of the default Docker Hub repository. Make sure to have push access set up before you actually push, and include port if needed. E.g.
For single architecture images, the above should suffice, the built image can be used in the host machine, and on other machines that have the same architecture too, i.e. after a push.
But for use-cases that need to support multiple architectures, there's a couple more things that need to be done. We need to create (or amend if already created beforehand) a manifest for the image(s) that we built, then annotate it to map the images to their respective architectures. And for our three tags created above we need to do it thrice.
Did you know?
We can inspect the manifest of any image by running
Assuming we built the images for all supported architectures, to facilitate pulling the correct image for the architecture, we can create/amend the latest manifest and annotate it to map the tags :aarch64, :armhf, :armv7l, :i386, :ppc64le, :riscv64, :s390x, :x86_64 to the tag :latest by running
makeannotate_latestROLE=master
How it works
First we create or amend the manifest with the tag latest
Next, to facilitate pulling images by version, we create/amend the image-version manifest and annotate it to map the tags :aarch64_${version}, :armhf_${version}, :armv7l_${version}, :i386_${version}, :ppc64le_${version}, :riscv64_${version}, :s390x_${version}, :x86_64_${version} to the tag :${version} by running
makeannotate_versionROLE=master
How it works
First we create or amend the manifest with the tag ${version}
Then, (optionally) we create/amend the ${version}_${builddate} manifest and annotate it to map the tags :aarch64_${version}_${builddate}, :armhf_${version}_${builddate}, :armv7l_${version}_${builddate}, :i386_${version}_${builddate}, :ppc64le_${version}_${builddate}, :riscv64_${version}_${builddate}, :s390x_${version}_${builddate}, :x86_64_${version}_${builddate} to the tag :${version}_${builddate} by running
makeannotate_dateROLE=master
How it works
First we create or amend the manifest with the tag ${version}_${builddate}
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