main.yml

# Clone the repo and check out the specified "commit" (defaults to master)
# unless it has already been checked out. Specifying "force" will clone and
# build regardless of prior status. When done, symlink the specified commit
# to make it go live, and remove old clones to free up disk space.

- name: check if specified commit has already been deployed
  stat: path={{base_path}}/{{commit}} get_checksum=no get_md5=no
  register: commit_dir

- include: checkout.yml
  when: force or not commit_dir.stat.exists

- name: link sha-named clone to make it live
  file:
    path: "{{site_path}}"
    state: link
    src: "{{base_path}}/{{ sha.stdout | default(commit) }}"
    force: yes

- name: update last-modification time of sha-named clone
  file: path={{base_path}}/{{ sha.stdout | default(commit) }} state=touch

- name: remove old clones to free up disk space
  shell: |
    # Find all 40-char-SHA-named child directories and for each directory, print
    # out the last-modified timestamp and the SHA.
    find . -mindepth 1 -maxdepth 1 -type d \
    -regextype posix-extended -regex './[0-9a-f]{40}' -printf '%T@ %P\n' |
    # Sort numerically in ascending order (on the timestamp), remove the
    # timestamp from each line (leaving only the SHA), then remove the most
    # recent SHAs from the list (leaving only the old SHAs-to-be-removed).
    sort -n | cut -d ' ' -f 2 | head -n -{{keep_n_most_recent}} |
    # Remove each remaining SHA-named directory and echo the SHA (so the task
    # can display whether or not changes were made).
    xargs -I % sh -c 'rm -rf "$1"; echo "$1"' -- %
  register: remove_result
  changed_when: remove_result.stdout != ""
  args:
    chdir: "{{base_path}}"
  when: keep_n_most_recent is defined