Capsule Helper

The capsule helper command takes as input a host of a capsule that will be accessed and ensures that an SSH configuration is in place to connect to the host as a capsule. This involves checking that the general capsule configuration is in place for the SSH client. When that is in place it will check that there is the HOST environment variable and generate a set of RSA encryption keys to use with that one host. The command will return quickly if there's nothing to do. It also outputs the SSH address to be used with the capsule. This makes it useful in UNIX shells as a subcommand to SSH tools that are not capsule aware. Here are some example usages.

$ capsule somehost
capsule@somehost
$ ssh $(capsule somehost)
Welcome to somehost...
$ git clone $(capsule somegitrepo):/mysrc
Cloning mysrc...
$ rsync -a $(capsule mybackup):/backup1 .

Ideally, someday this command will be no longer needed when either the popular SSH tools support capsules or if SSH itself supports them. Meanwhile, this tool is in place as a convenience.