From the Canyon Edge -- :-Dustin

Tuesday, August 2, 2011

Keep One SSH Tunnel to a Bip Proxy Server Running

I've been using IRC proxies on-and-off since 1999, and consistently since 2003.

I used dircproxy until February 2008, when I joined Canonical, at which point I switched to bip, as I needed support for SSL encrypted connections.

I've also helped at least a dozen friends and colleagues construct similar setups, so this blog post documentation is long, long overdue and triggered by another colleague asking me tonight to explain my setup again :-)

As you'll see below, it's not too complex, but it's really quite robust.  With this setup, all messages are logged, whether I'm attached or not.  When I'm not attached, I'm automatically marked 'away'.  All traffic between me and my server is encrypted.  Most importantly, my client marks any flagged messages/highlights that I missed each time I reconnect.

There are 4 key pieces to this setup:
  1. bip
  2. ssh
  3. keep-one-running
  4. xchat (or insert your favorite IRC client here)

The Server

I have a production, monitored Ubuntu server hosting www.divitup.com -- a side project that I authored back in college in 2000 to help split bills between roommates.  Long before the dawn of Facebook when Zuckerberg and the Winklevosses were still in high school :-)

It's an Ubuntu Server inside a VPS hosted by A2Hosting.com (with whom I've always been quite pleased!).  There's rarely downtime, but when there is, I hear about it from DivItUp users in a hurry.  It's the closest thing I have to an always-up server ;-)

Beside the DivItUp.com web service, it also runs SSH (of course) and I've installed the Bip Proxy service (though the port is not open externally).  Bip installs quite trivially on Ubuntu with:

sudo apt-get install bip

Though you may need to enable it in /etc/default/bip.

Bip can be configured globally for the server in /etc/bip.conf.  See the manpage and the inline comments in your default /etc/bip.conf, but this should give a decent idea of roughly how mine is configured:

ip = "127.0.0.1";
port = 7778;
client_side_ssl = true;
log_level = 3;
pid_file="/var/run/bip/bip.pid";
log_root = "/var/log/bip/";
log_format = "%n/%Y-%m/%c.%d.log";
log_sync_interval = 5;
backlog = true;
backlog_lines = 0;              # number of lines in backlog, 0 means no limit
backlog_always = false;         # backlog even lines already backlogged
backlog_msg_only = true;
blreset_on_talk = true;
backlog_reset_on_talk = true;

# Networks
network {
        name = "canonical";
        ssl = true;
        server { host = "irc.canonical.com"; port = 6697; };
};
network {
        name = "freenode";
        server { host = "irc.freenode.net"; port = 6667; };
};

network {
        name = "oftc";
        server { host = "irc.oftc.net"; port = 6667; };
};

# Users/channels
user { 
        name = "kirkland";      # bip user name (not IRC username)
        password = "88548dff20a3b2b72852b4256a7a3544";  # bip user password, generated by bipmkpw
        ssl_check_mode = "none";
        default_nick = "kirkland";              # IRC nick
        default_user = "kirkland";              # IRC user
        default_realname = "Dustin Kirkland";   # IRC real name

        # A user can have mutiple connections to irc networks.
        connection {
                name = "canonical";             # used by bip only
                network = "canonical";  # which ircnet to connect to
                user = "kirkland";
                realname = "Dustin Kirkland";
                password = "SomePassword";
                ignore_first_nick = true;
                no_client_away_msg = "currently disconnected";
                # Autojoined channels
                channel { name = "#a-channel,#another-channel,#maybe-a-third"; };
        };

        # another connection (optional)
        connection {
                name = "freenode";
                network = "freenode";
                ignore_first_nick = true;
                no_client_away_msg = "currently disconnected";
                on_connect_send = "PRIVMSG NickServ :IDENTIFY yourIRCpasswordHere";
                # Autojoined channels:
                channel { name = "#byobu"; };
                channel { name = "#ubuntu-devel"; };
                channel { name = "#ubuntu-meeting"; };
                channel { name = "#ubuntu-server"; };
                channel { name = "#ubuntu-cloud"; };
                # Password protected channel
                channel { name = "##the-good-stuff"; key = "zuperSekrit"; };
        };
};

Once you've installed and configured bip, start the service!

sudo service bip start

Now, let's take a look at the client...

The Client

Here, you really just need two things ... an always-running SSH tunnel to your server, and your IRC client.  I'll discuss Ubuntu/xchat here, but you can do the same with Android/AndChat.

There are several ways to configure an SSH tunnel (like stunnel), but here I'm going to show you the one that I'm partial toward :-)  I wrap an ssh port forwarding session with keep-one-running, and configure Unity to launch that automatically at boot.

My ssh command looks like this:

ssh -N -L 7778:localhost:7778 divitup.com


Now I want to make sure that there's always one, and only one of these running on my laptop client at all times.  I want it to automatically reconnect if I lose wireless connectivity, switch access points networks, suspend-and-resume, etc.  So I wrap that command with the keep-one-running utility.

keep-one-running ssh -N -L 7778:localhost:7778 divitup.com

And I set Unity (or Gnome/KDE/XFCE) to run this command at desktop login.  Alt-F2, "Startup Applications".


At login, I can run "ps -ef | grep keep-one-running" and see the command in my list.

Finally, I need to configure my IRC client, xChat, to talk to localhost:7778, rather than irc.freenode.net.

Here, you'll add a custom "network" for each of the server connections you defined in your /etc/bip.conf on the Server.   You'll use localhost/7778 for the hostname and port, since that's where you're SSH-port-forwarding to.  You'll enter your NickServ password (if you authenticate to IRC).  And you'll use the Server Password you created with bipmkpw.



Now, if you have an Android device, you can connect to the same proxy, by following my colleague, Juan Negron's supplementary post here!

Do you think you could improve your connectivity with such a setup?  Do you have a better way of solving this problem?

:-Dustin

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