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.
    • On Fedora/Redhat, run sudo yum install kernel-headers golang gcc.
  2. Git clone the flannel repo. It MUST be placed in your GOPATH under cd $GOPATH/src; git clone
  3. Run the build script, ensuring that CGO_ENABLED=1: cd flannel; CGO_ENABLED=1 make dist/flanneld

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

  • 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 for master builds. Releases are named (there is no -git suffix).