Ubuntu/Applications/PDSH - Revision history

R00t: /* Step 1: Password-less SSH */

2015-07-30T22:36:31Z

‎Step 1: Password-less SSH

R00t at 22:35, 30 July 2015

2015-07-30T22:35:31Z

R00t at 22:30, 30 July 2015

2015-07-30T22:30:03Z

R00t: /* Setup 1: Password-less SSH */

2015-07-30T22:26:55Z

‎Setup 1: Password-less SSH

R00t: Created page with "Applications | Java7 | Conky | Console Browsers | ..."

2015-07-30T22:26:43Z

Created page with "Applications | Java7 | Conky | Console Browsers | ..."

New page

[[Ubuntu/Applications|Applications]] | [[Ubuntu/Applications/Java7|Java7]] | [[Ubuntu/Applications/Conky|Conky]] | [[Ubuntu/Applications/Console_Browsers|Console Browsers]] | [[Ubuntu/Applications/Fail2Ban|Fail2Ban]] | [[Ubuntu/Applications/PDSH|PDSH]]

==Overview==
PDSH is currently (2015) one of the most popular solutions for Parallel Distributed Shell. It allows you to execute remote commands on a group or cluster of servers at the same time.

==Setup 1: Password-less SSH==
PDSH is not coded to handle authentication prompts, so it requires that you setup pair of authentication keys rather than using /passwd.
<br>
Create the ssh public/private keys on the host (computer you will be connecting FROM).
<nowiki>~$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/a/.ssh/id_rsa): [Enter key]
Created directory '/home/a/.ssh'.
Enter passphrase (empty for no passphrase): [Press enter key]
Enter same passphrase again: [Press enter key]
Your identification has been saved in /home/a/.ssh/id_rsa.
Your public key has been saved in /home/a/.ssh/id_rsa.pub.
The key fingerprint is:
3e:4f:05:79:3a:9f:96:7c:3b:ad:e9:58:37:bc:37:e4 a@A</nowiki>
<br>
Copy the public key to the remote-host (computer you will be connecting TO).
<nowiki>~$ ssh-copy-id -i ~/.ssh/id_rsa.pub remote-host
a@remote-host's password:
Now try logging into the machine, with "ssh 'remote-host'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.</nowiki>
<br>
You should now be able to ssh into the remote-host without a password:
<nowiki>~$ ssh remote-host
Last login: Sun Nov 16 17:22:33 2008 from 192.168.1.2
[Note: SSH did not ask for password.]

a@remote-host$ [Note: You are on remote-host here]</nowiki>

← Older revision		Revision as of 22:35, 30 July 2015
Line 42:		Line 42:
	==Step 3: send a test command from the host to a few servers==		==Step 3: send a test command from the host to a few servers==
	PDSH allows you to create a HOSTLIST which you can use to easily call groups of computers. I'm not going to cover that, but you can find more information about it by visiting their wiki [https://code.google.com/p/pdsh/wiki/UsingPDSH here].		PDSH allows you to create a HOSTLIST which you can use to easily call groups of computers. I'm not going to cover that, but you can find more information about it by visiting their wiki [https://code.google.com/p/pdsh/wiki/UsingPDSH here].
		+	<br>
		+	Send a test and see what OS each computer is running
		+	<nowiki>~$ pdsh -w ssh:username@host1,host2,host3 'grep . /proc/sys/kernel/ostype'</nowiki>
		+	If all the hostnames are similar except for the last digits, you can also do it this way:
		+	<nowiki>~$ pdsh -w ssh:username@host[1-3] 'grep . /proc/sys/kernel/ostype'</nowiki>

@@ Line 4: / Line 4: @@
 PDSH is currently (2015) one of the most popular solutions for Parallel Distributed Shell.  It allows you to execute remote commands on a group or cluster of servers at the same time.
-==Set 1: Password-less SSH==
+==Step 1: Password-less SSH==
 PDSH is not coded to handle authentication prompts, so it requires that you setup pair of authentication keys rather than using /passwd.
 <br>
@@ Line 34: / Line 34: @@
   a@remote-host$ [Note: You are on remote-host here]</nowiki>

@@ Line 21: / Line 21: @@
 Copy the public key to the remote-host (computer you will be connecting TO).
   <nowiki>~$ ssh-copy-id -i ~/.ssh/id_rsa.pub remote-host
-  a@remote-host's password:
+  a@remote-host's password: [Enter Password]
   Now try logging into the machine, with "ssh 'remote-host'", and check in: