Trac fails when last client cannot resolve dns of database server (postgres)

[Martin Marcher]

The setup is the following:

​https://10.200.2.5/$PROJECTNAME forwards to ​http://10.200.2.2/trac/$PROJECTNAME

the database host has the following DNS entries:

db            IN CNAME innsbruck
innsbruck     IN A     10.200.2.3

This works when the database is queried by IP (since I couldn't make the server publicly available I can only say that it works when the db server is reachable)

As soon as I use the mentioned database URI trac generates a internal server error. Both boxes the proxy (10.200.2.5 and 10.200.2.2) can resolve the host "db" just fine. The last client can't.

trac.ini doesn't work:

database = postgres://of_trac_sandbox:foobar@db/trac_sandbox

database = postgres://of_trac_sandbox:foobar@db.openforce.lan/trac_sandbox

trac.ini works:

database = postgres://of_trac_sandbox:foobar@10.200.2.3/trac_sandbox

DNS Works

ping -c1 db
PING innsbruck.openforce.com (10.200.2.3) 56(84) bytes of data.
64 bytes from innsbruck.openforce.lan (10.200.2.3): icmp_seq=1 ttl=64 time=0.384 ms

--- innsbruck.openforce.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.384/0.384/0.384/0.000 ms

Trac Error

[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend: Traceback (most recent call last):
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib/python2.4/site-packages/mod_python/apache.py", line 299, in HandlerDispatch\n    result = object(req)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/web/modpython_frontend.py", line 87, in handler\n    gateway.run(dispatch_request)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/web/wsgi.py", line 87, in run\n    response = application(self.environ, self._start_response)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/web/main.py", line 346, in dispatch_request\n    env = _open_environment(env_path, run_once=environ['wsgi.run_once'])
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/web/main.py", line 57, in _open_environment\n    env_cache[env_path] = open_environment(env_path)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/env.py", line 434, in open_environment\n    if env.needs_upgrade():
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/env.py", line 312, in needs_upgrade\n    db = self.get_db_cnx()
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/env.py", line 182, in get_db_cnx\n    return DatabaseManager(self).get_connection()
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/db/api.py", line 71, in get_connection\n    return self._cnx_pool.get_cnx()
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/db/pool.py", line 83, in get_cnx\n    cnx = self._connector.get_connection(**self._kwargs)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/db/postgres_backend.py", line 40, in get_connection\n    return PostgreSQLConnection(path, user, password, host, port, params)
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend:   File "/usr/lib64/python2.4/site-packages/trac/db/postgres_backend.py", line 110, in __init__\n    cnx = psycopg.connect(' '.join(dsn))
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] PythonHandler trac.web.modpython_frontend: OperationalError: could not translate host name "db" to address: Der Name oder der Dienst ist nicht bekannt\n
[Wed Nov 08 18:24:07 2006] [error] [client 10.200.2.107] File does not exist: /var/www/localhost/htdocs/favicon.ico

[Christian Boos]

Was most likely an InstallationIssue.