flannel/Documentation/building.md

Building flannel

The most reliable way to build flannel is by using Docker.

Building in a Docker container

To build flannel in a container run make dist/flanneld-amd64. You will now have a flanneld-amd64 binary in the dist directory.

Building for other platforms

If you're not running amd64 then you need to manually set ARCH before running make. For example, to produce a flanneld-s390x binary and image, run

• ARCH=s390x make image

If you want to cross-compile for a different platform (e.g. you're running amd64 but you want to produce arm binaries) then you need the qemu-static binaries to be present in /usr/bin. They can be installed on Ubuntu with

• sudo apt-get install qemu-user-static

Then you should be able to set the ARCH as above

• ARCH=arm make image

Building manually

1. Make sure you have required dependencies installed on your machine.
   • On Ubuntu, run sudo apt-get install linux-libc-dev golang gcc. If the golang version installed is not 1.7 or higher. Download the newest golang and install manully. To build the flannel.exe on windows, mingw-w64 is also needed. Run command sudo apt-get install mingw-w64
   • On Fedora/Redhat, run sudo yum install kernel-headers golang gcc glibc-static.
2. Git clone the flannel repo. It MUST be placed in your GOPATH under github.com/flannel-io/flannel: cd $GOPATH/src; git clone https://github.com/flannel-io/flannel.git
3. Run the build script, ensuring that CGO_ENABLED=1: cd flannel; CGO_ENABLED=1 make dist/flanneld for linux usage. Run the build script, ensuring that CGO_ENABLED=1: cd flannel; CGO_ENABLED=1 make dist/flanneld.exe for windows usage.

Release Process

1. Create a release on GitHub and use it to create a tag.
2. Check the tag out and run
   • make release
3. Attach all the files in dist to the GitHub release.
4. Run make docker-push-all to push all the images to a registry.

Obtaining master builds

A new build of flannel is created for every commit to master. They can be obtained from https://quay.io/repository/coreos/flannel-git

• latest is always the current HEAD of master. Use with caution
• The image tags have a number of components e.g. v0.7.0-109-gb366263c-amd64
  • The last release was v0.7.0
  • This version is 109 commits newer
  • The commit hash is gb366263c
  • The platform is amd64

These builds can be useful when a particular commit is needed for a specific feature or bugfix.

NOTE: the image name is quay.io/coreos/flannel-git for master builds. Releases are named quay.io/coreos/flannel (there is no -git suffix).