1 files changed, 142 insertions, 0 deletions
diff --git a/util/cleanup-github-caches.py b/util/cleanup-github-caches.py
new file mode 100755
index 000000000..41e4ede55
--- /dev/null
+++ b/util/cleanup-github-caches.py
@@ -0,0 +1,142 @@
+"""Cleans out the GitHub Actions cache by deleting obsolete caches.
+
+   Usage:
+   python cleanup-github-caches.py
+"""
+
+import collections
+import datetime
+import json
+import os
+import re
+import subprocess
+import sys
+
+
+def main(argv):
+  if len(argv) > 1:
+    raise ValueError('Expected no arguments: {}'.format(argv))
+
+  # Group caches by their Git reference, e.g "refs/pull/3968/merge"
+  caches_by_ref = collections.defaultdict(list)
+  for cache in get_caches():
+    caches_by_ref[cache['ref']].append(cache)
+
+  # Caclulate caches that should be deleted.
+  caches_to_delete = []
+  for ref, caches in caches_by_ref.items():
+    # If the pull request is already "closed", then delete all caches.
+    if (ref != 'refs/heads/master' and ref != 'master'):
+      match = re.findall(r'refs/pull/(\d+)/merge', ref)
+      if match:
+        pull_request_number = match[0]
+        pull_request = get_pull_request(pull_request_number)
+        if pull_request['state'] == 'closed':
+          caches_to_delete += caches
+          continue
+      else:
+        raise ValueError('Could not find pull request number:', ref)
+
+    # Check for caches with the same key prefix and delete the older caches.
+    caches_by_key = {}
+    for cache in caches:
+      key_prefix = re.findall('(.*)-.*', cache['key'])[0]
+      if key_prefix in caches_by_key:
+        prev_cache = caches_by_key[key_prefix]
+        if (get_created_at(cache) > get_created_at(prev_cache)):
+          caches_to_delete.append(prev_cache)
+          caches_by_key[key_prefix] = cache
+        else:
+          caches_to_delete.append(cache)
+      else:
+        caches_by_key[key_prefix] = cache
+
+  for cache in caches_to_delete:
+    print('Deleting cache ({}): {}'.format(cache['ref'], cache['key']))
+    print(delete_cache(cache))
+
+
+def get_created_at(cache):
+  created_at = cache['created_at'].split('.')[0]
+  # GitHub changed its date format so support both the old and new format for
+  # now.
+  for date_format in ('%Y-%m-%dT%H:%M:%SZ', '%Y-%m-%dT%H:%M:%S'):
+    try:
+      return datetime.datetime.strptime(created_at, date_format)
+    except ValueError:
+      pass
+  raise ValueError('no valid date format found: "%s"' % created_at)
+
+
+def delete_cache(cache):
+  # pylint: disable=line-too-long
+  """Deletes the given cache from GitHub Actions.
+
+  See https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-a-github-actions-cache-for-a-repository-using-a-cache-id
+
+  Args:
+    cache: The cache to delete.
+
+  Returns:
+    The response of the api call.
+  """
+  return call_github_api(
+      """-X DELETE \
+      https://api.github.com/repos/google/dagger/actions/caches/{0}
+      """.format(cache['id'])
+  )
+
+
+def get_caches():
+  # pylint: disable=line-too-long
+  """Gets the list of existing caches from GitHub Actions.
+
+  See https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#list-github-actions-caches-for-a-repository
+
+  Returns:
+    The list of existing caches.
+  """
+  result = call_github_api(
+      'https://api.github.com/repos/google/dagger/actions/caches'
+  )
+  return json.loads(result)['actions_caches']
+
+
+def get_pull_request(pr_number):
+  # pylint: disable=line-too-long
+  """Gets the pull request with given number from GitHub Actions.
+
+  See https://docs.github.com/en/rest/pulls/pulls?apiVersion=2022-11-28#get-a-pull-request
+
+  Args:
+    pr_number: The pull request number used to get the pull request.
+
+  Returns:
+    The pull request.
+  """
+  result = call_github_api(
+      'https://api.github.com/repos/google/dagger/pulls/{0}'.format(pr_number)
+  )
+  return json.loads(result)
+
+
+def call_github_api(endpoint):
+  auth_cmd = ''
+  if 'GITHUB_TOKEN' in os.environ:
+    token = os.environ.get('GITHUB_TOKEN')
+    auth_cmd = '-H "Authorization: Bearer {0}"'.format(token)
+  cmd = """curl -L \
+      {auth_cmd} \
+      -H \"Accept: application/vnd.github+json\" \
+      -H \"X-GitHub-Api-Version: 2022-11-28\" \
+      {endpoint}""".format(auth_cmd=auth_cmd, endpoint=endpoint)
+  return subprocess.run(
+      [cmd],
+      check=True,
+      shell=True,
+      capture_output=True
+  ).stdout.decode('utf-8')
+
+
+if __name__ == '__main__':
+  main(sys.argv)