nik - a stupid Docker hostfile updater

You want your containers to know about each other? You got it. For the low low price of a couple of CPU cycles, I will happily inject the names and IP addresses of all your containers into all your other containers! How cool is that?

Of course, I am very stupid and you should not use me in production. What's that? You *will run me in production? Oh, I'm tickled pink. Let's hope I don't leak memory or something.

Quickstart

Start up the updater process:

$ ./nik

Now, in a separate console, try:

$ docker run -d --hostname apple busybox sleep 600
$ docker run -d --hostname pear busybox sleep 600
$ docker run -ti --rm --hostname userguy busybox /bin/sh

You should be able to ping pear and apple. Your /etc/hosts should have both entries.

For bonus points, in yet another console do:

$ docker run -d --hostname watermelon busybox sleep 600

Now ping watermelon from your userguy shell.

Details

• all containers are injected with their Hostname, make sure to set it using --hostname
• the -i flag controls the check interval