Working on remote unix hosts

After much tweaking, I’ve found a good way of working with a set of geographically distributed unix hosts. This isn’t the most exciting topic in the world but, like your choice of keyboard, it affects you every minute you spend working at a computer. So it’s worth some attention.

Every day, I work on localhost and three other (distant) servers. I run gnome-terminal with four tabs, one per host so I can switch between hosts with alt-1-4. Each tab has its own ‘profile’ which I use to set a slight background tint as a visual reminder of which host I’m working on, as well as showing the hostname in the tab title. Why gnome-terminal? Well, because it does unicode right and has tabs – it’s dog slow at rending though. I tried urxvt for a while, but went back to gnome-terminal.

In each tab, I run “ssh -tt HOST screen -DR” to login to the remote host and reconnect to my GNU screen session. This gives all of the win. Firstly, it makes it easy to start new shells on that host without the overhead of a new ssh login. When I say ‘overhead’ I mean both time to do ssh connection negotiation (these are distant hosts) and the niggling asymmetry of ControlMaster. Using screen inside gnome-terminal effectively gives me two dimensions of tabs (and two sets of keybindings) but it works well.

The second win of screen is that if my internet connection goes down or my localhost crashes, I don’t lose my state. Any long running jobs on the remote hosts are still running just fine when I log back in and reconnect to screen. I can also connect to the screen session from different places. For example, I can leave a long job running whilst I cycle home and check on it from home.

The last piece of the puzzle is emacs. I love emacs, and the recent multitty support is just awesome. However, it’s a bit of a pain having to have my ‘actual’ emacs running on a real tty, when 99% of the time I ‘use’ it via emacsclient -t. However, I recently started running emacs under detachtty which allows you to run the main emacs process ‘headless’. I also saw a patch to do the same thing direct in emacs. So now I have a ‘headless’ emacs running on each host 24/7. Then, when I want to edit something I used ’emacsclient -t’ to temporarily connect my current terminal to it. And when I’m done, C-x C-c disconnects from emacs but doesn’t actually kill it. So my emacs now acts like a zero-startup time lightweight editor, but I get all the advantages of a having long-running emacs process. And I don’t have to worry about accidentally closing the window which the ‘real’ emacs is running in. Sweet.

It occurs to me that there’s a lot of duplication in the setup. Screen and detachtty and emacs have overlapping features in numerous ways. Emacs/screen can manage multiple shells, screen/detachtty do the ‘tty decoupling’ thing. But it’d take work to make emacs manage multiple shells as nicely as screen does. And screen-inside-gnometerminal is easier to manage than remote-screen-inside-local-screen. I think I’ve got to a pretty sweet spot with this setup.