Native SSH HOWTO
Native ssh support is available with Munin 2.0 or later (in beta as of 2011-07-04). This page describes how to use that.
There are two ways to use this.
SSH with a 2.0 master
This section is for when you have a 2.0 master and root on the munin-nodes. You can use it with any version of munin-node.
If you don't have root on the nodes you can manage without that too - see further down.
- You need netcat (nc) installed on the nodes. *BSD and Linux machines either has this installed or easily available in the package system.
- On the nodes you want to use SSH with, you first install a munin-node in the normal way (package or from source code).
- If the node is not configured with the right plugins you run "munin-node-configure --shell | sh -x"
- Ensure that munin-node is running
- Generate a SSH key for the munin-master munin user the normal way (e.g. using ssh-keygen).
- Install the public SSH key in the authorized_keys file in the munin account on all the SSH-based Munin nodes
- Use SSH from the munin account on the munin-master to log in to the munin account on all the SSH-based nodes so that you know all the keys are in order. Use the same hostname as you will use in Munin so that the host names match.
- You have to set the shell for the munin user on the munin-nodes to something other than "nologin", using e.g. the "chsh" command to do that (e.g. chsh -s /bin/sh munin).
- To get the SSH in touch with the Munin node, we use the netcat program. On the systems I have here this command is in /usr/bin/nc. on Debian systems it's /bin/nc
- So on the master I enter the following in munin.conf and hey presto, it all works!
[floppa.example.com] address ssh://floppa.example.com/usr/bin/nc localhost 4949
If your netcat supports the -q option you should probably add -q 0 to the command line (this needs verification, anyone?)
Then wait the accustomed 5-10 minutes and check the results in the munin web interface.
try to SSH to the host and execute the command as the munin user. copy&paste that from the address section
$ su - munin shell=/bin/bash $ ssh floppa.example.com /usr/bin/nc localhost 4949
SSH with pre-2.0 Munin nodes - not root on the node
This is documented in http://blog.pwkf.org/post/2010/07/Waiting-for-Munin-2.0-Native-SSH-transport this article for the time being.