Add a script to recreate a workspace repo

This uses the new workspace-repos.json file to allow users to
recreate the workspace repo contents used in a previously run
build.

Change-Id: Ifaab7c02b5c6f5990488dd0015f168a9aa7e60f6

tools/replay-workspace.py

@@ -0,0 +1,102 @@
+# Copyright 2024 Acme Gating, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import json
+import argparse
+import os
+import subprocess
+import logging
+import sys
+
+parser = argparse.ArgumentParser(
+    description="Replay the Zuul workspace repo setup using information "
+    "saved from a Zuul build's workspace-repos.json file.")
+parser.add_argument('file', help='Path to workspace-repos.json')
+parser.add_argument('-v', action='store_true', help='Verbose logging')
+parser.add_argument('--workspace', help='Path to workspace')
+options = parser.parse_args()
+
+if options.v:
+    logging.basicConfig(level=logging.DEBUG)
+else:
+    logging.basicConfig(level=logging.INFO)
+
+
+class CloneException(Exception):
+    pass
+
+
+class Workspace:
+    def __init__(self, path):
+        self.path = path
+        self.log = logging.getLogger('workspace')
+
+    def run(self, cmd, cwd, timestamp=None, level=logging.INFO):
+        self.log.log(level, 'Run: "%s"', ' '.join(cmd))
+        env = self.env
+        if timestamp:
+            env = env.copy()
+            env['GIT_COMMITTER_DATE'] = str(int(timestamp)) + '+0000'
+            env['GIT_AUTHOR_DATE'] = str(int(timestamp)) + '+0000'
+        subprocess.run(cmd, cwd=cwd, env=env, check=True)
+
+    def load(self, fn):
+        with open(fn) as f:
+            data = json.load(f)
+        self.repo_state = data['repo_state']
+        self.merge_ops = data['merge_ops']
+        self.merge_name = data['merge_name']
+        self.merge_email = data['merge_email']
+        self.env = {
+            'GIT_AUTHOR_NAME': self.merge_name,
+            'GIT_AUTHOR_EMAIL': self.merge_email,
+            'GIT_COMITTER_NAME': self.merge_name,
+            'GIT_COMITTER_EMAIL': self.merge_email,
+        }
+
+    def clone(self):
+        for repo, state in self.repo_state.items():
+            path = os.path.join(self.path, repo)
+            fail = False
+            if not os.path.exists(path):
+                self.log.error("Please clone the repo %s", repo)
+                fail = True
+            if fail:
+                raise CloneException()
+
+    def reset(self):
+        for repo, state in self.repo_state.items():
+            path = os.path.join(self.path, repo)
+            for ref, sha in state.items():
+                self.run(['git', 'update-ref', ref, sha],
+                         cwd=path, level=logging.DEBUG)
+
+    def replay(self):
+        for op in self.merge_ops:
+            if 'cmd' in op:
+                self.run(op['cmd'],
+                         cwd=os.path.join(self.path, op['path']),
+                         timestamp=op.get('timestamp'))
+            if 'comment' in op:
+                self.log.info(op['comment'])
+
+
+w = Workspace(options.workspace or os.getcwd())
+w.load(options.file)
+try:
+    w.clone()
+except CloneException:
+    sys.exit(1)
+w.reset()
+w.replay()