PostgreSQL environment upgrade issue

[Emmanuel Blot]

I'm in the process of migrating from SQLite to PostgreSQL DB backend, and I have to upgrade the environment once more to upgrade Bitten.

I ran "trac-admin project" upgrade command and received the following error:

Trac [/local/var/trac/projects/tools]> upgrade
KeyError: 'params'

It ends up to be an issue here:

# trac/db/postgres_backend.py
def backup(self, dest_file):
        # line 114
        if 'host' in db_prop['params']:
            host = db_prop['params']['host']
        else:
            host = db_prop.get('host', 'localhost')

This part of the code does not seems to match the construction of the db_prop dictionary, from trac/db/api.py

def _parse_db_str(db_str):
   # ...
   args = zip(('user', 'password', 'host', 'port', 'path', 'params'),
               (user, password, host, port, path, params))
   return scheme, dict([(key, value) for key, value in args if value])

where params may not be a dictionary entry if no value is tied to params

Here is a quick workaround to bypass the issue, although I'm not sure it's valid (no time to understand the nuts and bolts of this backend for now…)

trac/db/postgres_backend.py

@@ -111 +111 @@
         args = [self.pg_dump_path, '-C', '-d', '-x', '-Z', '8',
                 '-U', db_prop['user'],]
         port = db_prop.get('port', '5432')
-        if 'host' in db_prop['params']:
-            host = db_prop['params']['host']
+        if 'host' in db_prop:
+            host = db_prop['host']
         else:
             host = db_prop.get('host', 'localhost')
         args.append('-h')
@@ -121 +121 @@
             args.append('-p')
             args.append(str(port))
 
-        if 'schema' in db_prop['params']:
-            args.extend(['-n', db_prop['params']['schema']])
+        if 'params' in db_prop:
+            if 'schema' in db_prop['params']:
+                args.extend(['-n', db_prop['params']['schema']])
 
         dest_file += ".gz"
         args.extend(['-f', dest_file, db_name])

Note: it might be nice to have a "DB backend" component to report issues against.

[Felix Schwarz <felix.schwarz@…>]

eblot: I think your patch is wrong because it there is there else clause which uses 'host' already. The real problem is that db_propparams could be missing as you already noted.

I'm attaching a preliminary patch for 0.11

[Felix Schwarz <felix.schwarz@…>]

Btw: The same problem exists in 0.11 so please fix the issue on all branches.

[Remy Blank]

Working on that.

[Remy Blank]

Felix is right, db_prop['params'] can be missing, and his patch fixes the issue. Applied in [8312], thanks!

The logic for 'host' is correct, and handles the case where the host is specified as an additional parameter, which is useful if you connect to PostgreSQL through a UNIX socket. See DatabaseBackend#Postgresql for more details.

it might be nice to have a "DB backend" component to report issues against.

Wish granted :-)