When using servers that are on an intranet or set up "in the cloud", such as on EC2, it is often the case that the hostname and IP number of the machine, internal to itself, is different from the hostname and IP number used to reach services on the machine from outside.

TiddlyWeb uses hostname and port number information to handle the creation of URLs in redirects and information sent to the client. To set these things adjust the server_host config setting in tiddlywebconfig.py.

When you do this on a machine with different internal and external hostnames, you need to use the external hostname, however you may see errors such as

    socket.error: (99, 'Cannot assign requested address')

because the external hostname or IP number is not valid for the local interface. To get around this you need to add the external hostname as an alias for the local host. On Unix-like machines this means adding to {{{/etc/hosts}}}.

Note that if you are hosting TiddlyWeb on a server such as apache or nginx which proxies to the WSGI application, the data in server_host is only used for creation of URLs: The server controls the interface on which it listens.