some more README work

[git-mirror.git] / webhook-core.py

diff --git a/webhook-core.py b/webhook-core.py
index bff1137f884e3481913b79301d41ba0557f93dfe..83cb03edd31c1ebd8c135ac4c4ea8c1f32b68df2 100755 (executable)
--- a/webhook-core.py
+++ b/webhook-core.py
@@ -24,43 +24,71 @@
 #==============================================================================
 
 # This is the hook called by GitHub as webhook. It updats the local repository, and then all the other mirrors.
-import sys, traceback
+import sys, traceback, json
 from git_mirror import *
 
+def get_github_payload(repo, signature):
+    '''Return the github-style JSON encoded payload (as if we were called as a github webhook)'''
+    data = sys.stdin.buffer.read()
+    verify_signature = repo.compute_hmac(data)
+    if signature != "sha1="+verify_signature:
+        raise Exception("You are not GitHub!")
+    try:
+        data = json.loads(data.decode('utf-8'))
+        return data
+    except ValueError:
+        return {} # nothing read
+
+
 if __name__ == "__main__":
+    # call this with: <reponame> <event name> <signature>
     repo = None # we will try to use this during exception handling
     try:
         repos = load_repos()
-        reponame = sys.argv[1] if len(sys.argv) > 1 else None
+        if len(sys.argv) < 4:
+            raise Exception("Usage: {} <reponame> <event name> <signature>".format(os.path.basename(sys.argv[0])))
+        reponame = sys.argv[1]
+        githubEvent = sys.argv[2]
+        githubSignature = sys.argv[3]
         if reponame not in repos:
             raise Exception("Repository missing or not found.")
         repo = repos[reponame]
         
         # now sync this repository
-        data = get_github_payload()
-        ref = data["ref"]
-        oldsha = data["before"]
-        newsha = data["after"]
-        # validate the ref name
-        if re.match('refs/[a-z/]+', ref) is None:
-            raise Exception("Invalid ref name {0}".format(ref))
-        # collect URLs of this repository, to find the mirror name
-        urls = []
-        for key in ("git_url", "ssh_url", "clone_url"):
-            urls.append(data["repository"][key])
-        mirror = repo.find_mirror_by_url(urls)
-        if mirror is None:
-            raise Exception("Could not find the mirror.")
-        repo.update_ref_from_mirror(ref, oldsha, newsha, mirror, suppress_stderr = True)
-        # print an answer
-        print("Content-Type: text/plain")
-        print()
-        print("Updated {0}:{1} from mirror {2} from {3} to {4}".format(reponame, ref, mirror, oldsha, newsha))
+        data = get_github_payload(repo, githubSignature)
+        if githubEvent == 'ping':
+            # github sends this initially
+            print("Content-Type: text/plain")
+            print()
+            print("Pong!")
+            sys.exit(0)
+        elif githubEvent == 'push':
+            ref = data["ref"]
+            oldsha = data["before"]
+            newsha = data["after"]
+            # validate the ref name
+            if re.match('refs/[a-z/]+', ref) is None:
+                raise Exception("Invalid ref name {}".format(ref))
+            # collect URLs of this repository, to find the mirror name
+            urls = []
+            for key in ("git_url", "ssh_url", "clone_url"):
+                urls.append(data["repository"][key])
+            mirror = repo.find_mirror_by_url(urls)
+            if mirror is None:
+                raise Exception("Could not find the mirror.")
+            stdout = repo.update_ref_from_mirror(ref, oldsha, newsha, mirror, suppress_stderr = True)
+            # print an answer
+            print("Content-Type: text/plain")
+            print()
+            print("Updated {}:{} from mirror {} from {} to {}".format(reponame, ref, mirror, oldsha, newsha))
+            print(stdout)
+        else:
+            raise Exception("Unexpected github event {}.".format(githubEvent))
     except Exception as e:
         if repo is not None:
-            repo.mail_owner("There was a problem running the git-mirror webhook:\n\n{0}".format(traceback.format_exc()))
+            repo.mail_owner("There was a problem running the git-mirror webhook:\n\n{}".format(traceback.format_exc()))
         # do not print all the details
         print("Status: 500 Internal Server Error")
         print("Content-Type: text/plain")
         print()
-        print("We have a problem:\n{0}".format('\n'.join(traceback.format_exception_only(type(e), e))))
+        print("We have a problem:\n{}".format('\n'.join(traceback.format_exception_only(type(e), e))))