sshcommand 
Simplifies running a single command over SSH, and manages authorized keys (ACL) and users in order to do so.
It basically simplifies running:
ssh user@server 'ls -l <your-args>'
into:
ssh ls@server <your-args>
Commands
sshcommand create <USER> <COMMAND> # Creates a user forced to run command when SSH connects
sshcommand acl-add <USER> <NAME> <KEY_FILE> # Adds named SSH key to user from STDIN or argument
sshcommand acl-remove <USER> <NAME> # Removes SSH key by name
sshcommand list <USER> [<NAME>] # Lists SSH keys by user and an optional name
sshcommand help <COMMAND> # Shows help information
sshcommand version # Shows version
Example
On a server, create a new command user:
$ sshcommand create cmd /path/to/command
On your computer, add authorized keys with your key:
$ cat ~/.ssh/id_rsa.pub, ssh root@server sshcommand acl-add cmd progrium
If the public key is already on the server, you may also specify it as an argument:
$ ssh root@server sshcommand acl-add cmd progrium ~/.ssh/id_rsa.pub
Now anywhere with the private key you can easily run:
$ ssh cmd@server
Anything you pass as the command string will be appended to the command. You can use this
to pass arguments or if your command takes subcommands, expose those subcommands easily.
$ /path/to/command subcommand
Can be run remotely with:
$ ssh cmd@server subcommand
When adding an authorized key, you can also specify custom options for AUTHORIZED_KEYS
by specifying the SSHCOMMAND_ALLOWED_KEYS environment variable. This should be a list
of comma-separated options. The default keys are as follows:
no-agent-forwarding,no-user-rc,no-X11-forwarding,no-port-forwarding
This can be useful for cases where the ssh server does not allow certain options or you
wish to further constrain a user's environment. Please see man sshd for more information.