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CarpeNoctem
Asked: 2014-01-15 13:33:26 +0800 CST

expand hostnames to fqdn before calling ssh?

  • 772

I make use of an .ssh/config file to set my username appropriately based on a given portion of a subdomain, e.g.

Host *widgetshop.com*
   User foobar
   ControlMaster auto
   ControlPath ~/.ssh/socket-%r@%h:%p

Host *
   ControlMaster auto
   ControlPath ~/.ssh/socket-%r@%h:%p

This works if I write:

ssh foo.widgetshop.com

but does not work if I were to write:

ssh foo

which upon search path resolution becomes the same fqdn.

Anyone have a way to expand shortnames before calling ssh, or an alternative approach?

domain-name-system

4 Answers

  1. As of OpenSSH 6.5, you can do this with the CanonicalizeHostname option in ssh_config. Here's an example that should do what you want:

    CanonicalizeHostname yes
CanonicalDomains widgetshop.com

Host *.widgetshop.com
     User foobar
    • 6
  2. Best Answer

    Perhaps you can use the host command:

    ssh $(host -t A  foo | cut -f1 -d" ")

    Put that into a shell script (replace "foo" with "$1") and exec ssh.

    • 5

  3. The ssh_config manpage answers this:

    The host is the hostname argument given on the command line (i.e. the name is not converted to a canonicalized host name before matching).

    In other words, it doesn't work because it doesn't work that way.

    • 0

  4. please see my "alternative approach")

    mbp:~ alexus$ grep f9 /etc/hosts
XX.XXX.XX.XXX   f9
mbp:~ alexus$ ssh f9 hostname
f9.XXX.org
mbp:~ alexus$
    • -1