Add script for launching git daemon on random port

This starts the git daemon procvess in inetd mode, so we can bind to an
ephemeral port, and still be able to report which port was used, so
we can construct git URIs using a non-standard port to talk to simulated
git servers.

1 files changed, 46 insertions, 0 deletions

diff --git a/scripts/git-daemon-wrap b/scripts/git-daemon-wrap
new file mode 100755
index 00000000..528b7bed
--- /dev/null
+++ b/scripts/git-daemon-wrap
@@ -0,0 +1,46 @@
+#!/usr/bin/python
+
+'Launch a Git Daemon on an ephemeral port, and report which port was used.'
+
+import argparse
+import contextlib
+import pipes
+import socket
+import subprocess
+import sys
+
+# Parse arguments with bare argparse, since cliapp hates unknown options
+class UnsupportedArgument(argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        sys.stderr.write('%s not supported\n' % option_string)
+        sys.exit(1)
+
+parser = argparse.ArgumentParser(description=__doc__)
+for arg in ('user', 'group', 'detach', 'port', 'syslog', 'pid-file'):
+    parser.add_argument('--' + arg, action=UnsupportedArgument)
+parser.add_argument('--listen', default='127.0.0.1')
+parser.add_argument('--port-file', required=True,
+                    help='Report which port the git daemon was bound to.')
+options, args = parser.parse_known_args()
+
+with contextlib.closing(socket.socket()) as sock:
+    sock.bind((options.listen, 0))
+    host, port = sock.getsockname()
+    with open(options.port_file, 'w') as f:
+        f.write('%s\n' % port)
+    sock.listen(1)
+    while True:
+        conn, addr = sock.accept()
+        with contextlib.closing(conn):
+            gitcmd = ['git', 'daemon', '--inetd']
+            gitcmd.extend(args)
+            cmdstr = (' '.join(map(pipes.quote, gitcmd)))
+            sys.stderr.write('Running %s' % cmdstr)
+            ret = subprocess.call(args=gitcmd, stdin=conn, stdout=conn,
+                                  stderr=conn, close_fds=True)
+            if ret != 0:
+                sys.stderr.write('%s exited %d\n' % (cmdstr, ret))
+            # git-daemon returns 255 when the repo doesn't exist
+            if ret not in (0, 255):
+                break
+sys.exit(ret)