Add instruction on setting up ssh connections

Signed-off-by: Sachin Prabhu <[email protected]>

Author: spuiuk

docs/SSH-Configuration.md

@@ -0,0 +1,46 @@
+##Instructions on setting up your ssh configuration to allow for easy access to the test machines.##
+
+Ensure you have your public ssh key(an any other public keys) added to autorized_files and call the fix_ssh.yml ansible playbook using the command
+```
+make fix_ssh
+```
+in the admin directory.
+
+The host machine which has the test vms have the following entries.
+```
+192.168.123.5 client1
+192.168.122.200 setup
+192.168.122.100 storage0
+192.168.122.101 storage1
+```
+
+If accessing from the host machines, you can simply ssh into the machines as listed in the /etc/hosts.
+
+However in my case, I run my test cluster on a remote test machine which can be accessed over ssh. To enable easy access from my local desktop, I have the following setup.
+
+The /etc/hosts on the remote host machine is as follows
+```
+192.168.123.5 t-client1
+192.168.122.200 t-setup
+192.168.122.100 t-storage0
+192.168.122.101 t-storage1
+```
+Here an arbitrary string 't-' is prepended to the host names and its use will be evident shortly.
+
+On my desktop, I have an entry for the remote host in /etc/hosts
+192.168.21.66 t
+
+I also have the following ssh configuration appended to .ssh/config
+```
+Host t
+        Hostname t
+        KeepAlive yes
+        ControlMaster yes
+        ControlPath /tmp/t_ssh
+        
+Host t-*
+        ProxyCommand ssh -S /tmp/t_ssh exec nc %h %p
+        StrictHostKeyChecking no
+        UpdateHostKeys yes
+```
+To initiate a ssh connection to the test machines on the remote host, I first connect to the remote host over ssh using hostname 't'. This opens a control path /tmp/t_ssh. Subsequently connections to test machines eg: t-storage0 uses this control path to open a ssh connection to storage0 on the remote host.