Overview

Stapel is an LFS based linux distribution, which contains:

  • Glibc
  • Gnu cli tools (install, patch, find, wget, grep, rsync and other)
  • Git cli util
  • Bash
  • Python interpreter
  • Ansible

Stapel tools built in non-standard root location. Binaries, libraries and other related files are located in the following directories:

  • /.werf/stapel/(etc|lib|lib64|libexec)
  • /.werf/stapel/x86_64-lfs-linux-gnu/bin
  • /.werf/stapel/embedded/(bin|etc|lib|libexec|sbin|share|ssl)

The base of stapel is a Glibc library and linker (/.werf/stapel/lib/libc-VERSION.so and /.werf/stapel/x86_64-lfs-linux-gnu/bin/ld). All tools from /.werf/stapel are compiled and linked only against libraries contained in /.werf/stapel. So stapel is a self-contained distribution of tools and libraries without external dependencies with an independent Glibc, which allows running these tools in arbitrary environment (independently of linux distribution and libraries versions in this distribution).

Stapel filesystem /.werf/stapel is intent to be mounted into build container based on some base image. Tools from stapel can then be used for some purposes. As stapel tools does not have external dependencies stapel image can be mounted into any base image (alpine linux with musl libc, or ubuntu with glibc — does not matter) and tools will work as expected.

werf mounts stapel image into each build container when building docker images with stapel builder to enable ansible, git service operations and for other service purposes. More info about stapel builder are available in the article.

Change, update and rebuild stapel

Stapel image needs to be updated time to time to update ansible or when new version of LFS is available.

  1. Make necessary changes to build instructions in stapel directory.
  2. Update omnibus bundle: 
    cd stapel/omnibus
bundle update
git add -p Gemfile Gemfile.lock
  3. Build new stapel images: 
    scripts/stapel/build.sh

    This command will create flant/werf-stapel:dev and secondary flant/werf-stapel-base:dev docker images.

  4. To test this newly built stapel image export environment variable WERF_STAPEL_IMAGE_VERSION=dev prior running werf commands: 
    export WERF_STAPEL_IMAGE_VERSION=dev
werf build ...
  5. Publish new stapel images: 
    scripts/stapel/publish.sh NEW_VERSION
  6. As new stapel version has been published change VERSION Go constant in the pkg/stapel/stapel.go to point to the new version and rebuild werf.