A multisite capable Drupal site-builder based on JSON-recipes.
- Download and extract packages, prepare a Drupal tree and run "drush site-install" all from the same set of configuration files.
- Package lists and site-configurations are pure JSON (ie. easy machine-generateable).
- configuration files can "include" other json-files (even remote files).
- Built-in support for multisite installations (optimized for sharing code in a manageable way).
- Install files from: git repositores, tarballs, local directories, copy files, patches
- Fast: if you change only one project (ie. add a patch) only this project is rebuilt.
- Use hashes to check the integrity of downloaded files.
- Python3
- git
- drush (for running site-install)
- rsync
- A symlink capable file-system
- Why not simply use drush make? For our multi-site setup we'd like a directory structure that looks something like:
projects/  # packages
  module1-7.x-1.0/   # code of module1
  module1-7.x-2.1/   # another version of module1
  somesite/          # code of the custom somesite projects
  theproject/        # another custom project with a install_profile
htdocs/    # drupal-root
  profiles/
  theproject/ -> ../../projects/theproject
  minimal/
  standard/
  testing/
  sites/
    somesite/
    modules/         # symlinks to projects in the projects sub-folder
      contrib/       # only one copy of a module per version.
        module1 -> ../../../../../projects/module1-7.x-1.0
        …
    themes/
      contrib/
        theme1 -> ../../../../../projects/theme1-7.x-1.0
        …
  othersite/
    modules/
    contrib/         # allow different versions of a module per site
      module1 -> ../../../../../projects/module1-7.x-2.0
Directory layouts like this seems rather cumbersome with drush make
which seems to be a bit biased towards a one-drupal-tree-per-site
approach of hosting.
- 
Why not use sites/all/ for code-sharing? sites/all/ doesn't allow us to update modules site by site. If an module has an update-hook (ie. brings down your site until drush updb is run) you have to update the module-code. Then you need to run drush updb in all sites to bring them online again. So the mean down-time for a site is: n/2. With lots of sites this can take quite some time. 
- 
Why care for code sharing at all? Sharing the code for modules means that our opcode cache needs to hold only one copy of a file instead of one per site.