Web interface Error:Could not read object configuration data

[zander_2]

When you are doing this via cli, are you running as root or the nagios user? You very possibly need to do this as the nagios user, or accept the ssh key as the nagios user via a manual ssh over first. Otherwise the plugin will just fail. However the 255 out of bounds is still a bit strange.

Hm, well this is interesting. Yes, I was running it on root, and this is probably a problem, if not the problem. The weird thing is that when I do su - nagios on my nagios server and try to ssh to an account (I called it nagios, too) on the other machine, it prompts me for a password even though I don't have the account password protected. This would definitely be a block to Nagios when it tried to do it automatically. Now, the question is, why is it asking my for a password? I set up an RSA key and copied it to the authorized_keys file on the second machine and I'm pretty sure I did that properly.

[abrist]

Try logging in as root, and then su'ing over to the user nagios. root should be able to su to any user . . .

[zander_2]

Try logging in as root, and then su'ing over to the user nagios. root should be able to su to any user . . .

I can su to nagios, but after that when I'm trying to ssh an un-passworded account on another machine, it asks me for a password anyway. That's what I don't get; I can access the nagios account on the server just fine.

[lmiltchev]

I am now sure what is causing that, but I would recommend re-generating the keys:

On the nagios server, run:

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su nagios
ssh-keygen

Press "Enter" and accept defaults (don't enter a password). Public and private SSH keys will be generated and saved in: "/home/nagios/.ssh".

On the remote box, run:

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su nagios
ssh-keygen

Press "Enter" and accept defaults (don't enter a password).

Go back to the nagios server, and copy the public key of the nagios user on the nagios server to the authorized_keys for the nagios user on the remote box.

Make sure, the permissions are correct - you should have something like this:

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[nagios@localhost .ssh]$ ls -al
total 24
drwx------ 2 nagios users 4096 Jul 16 09:44 .
drwx------ 3 nagios users 4096 Jul 16 09:43 ..
-rw------- 1 nagios users 410 Jul 16 09:44 authorized_keys
-rw------- 1 nagios users 1675 Jul 16 09:43 id_rsa
-rw-r--r-- 1 nagios users 410 Jul 16 09:43 id_rsa.pub

Verify that you can login to the remote server without supplying a password by suing the following commands on the nagios server:

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su nagios
ssh nagios@<remote_IP>

where you replace <remote_IP> with the IP addres of the remote linux server.

After you verified you could log in without password, try running your check again.

[zander_2]

Nope, will not connect. It just keeps asking for a password, even though the nagios account doesn't even have a password. I set up a working SSH between two other VMs just the other day, so I don't know why it's acting any differently here. That's definitely the problem.

[abrist]

If it is asking for your password, the keys are probably not in the right place.
What is the output of:

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ls -la /home/nagios/.ssh

Run this on both the nagios server and remote host.

[zander_2]

If it is asking for your password, the keys are probably not in the right place.
What is the output of:

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ls -la /home/nagios/.ssh

Run this on both the nagios server and remote host.

On the server, it's:

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drwx------ 2 nagios nagios 4096 Aug 19 14:13 .
drwx------ 3 nagios nagios 4096 Aug 19 14:04 ..
-rw------- 1 nagios nagios 1675 Aug 19 14:11 id_rsa
-rw-r--r-- 1 nagios nagios  414 Aug 19 14:11 id_rsa.pub
-rw-r--r-- 1 nagios nagios  409 Aug 19 14:08 known_hosts

And on the remote host, it's:

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drwxrwxr-x 2 nagios nagios 4096 Aug 19 10:12 .
drwx------ 3 nagios nagios 4096 Aug 19 10:09 ..
-rw-rw-r-- 1 nagios nagios  415 Aug 19 10:12 authorized_keys
-rw------- 1 nagios nagios 1675 Aug 19 10:11 id_rsa
-rw-r--r-- 1 nagios nagios  415 Aug 19 10:11 id_rsa.pub

I noticed in your last post you had an authorized_keys file in the .ssh folder of the server, which I don't think is necessary. However, I'm not so sure about the lack of a known_hosts file on the remote host. Not sure what's up with the really lax permissions on .ssh folder on the remote host, but again, I don't think that matters. I can remove the excess if you like.

[abrist]

What is in the "authorized_keys" directory on the remote host?

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ls -la /home/nagios/.ssh/authorized_keys 

Do you have any restrictions setup on the "nagios" account on the remote system?

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grep nagios /etc/shadow

[lmiltchev]

Are you sure that you copied the public key of the nagios user on the nagios server to the authorized_keys for the nagios user on the remote box?

Open both files in a text editor:

on the nagios server: /home/nagios/.ssh/id_rsa.pub
on the remote box: /home/nagios/.ssh/authorized_keys

and compare them. They should be identical.

[zander_2]

What is in the "authorized_keys" directory on the remote host?

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ls -la /home/nagios/.ssh/authorized_keys 

It's not a directory, it's a file containing the server's public key. It reads:

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ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA8PkNpfoe+QXEuD4MEt/pS7Jri4e5sYjwUDmCAIIioaPj7mACS/MhD3EAQ3l01qOaBjvE1cubZOzDDmYnvlAGmeqtPynZSCITUykQcaT9xPXTei3Lk9QOnW5On+v5/UhoMjGiV+q65sPVOLCpT/Rj/RkL+cau+tAnRE1MMWpyME/0EZM3w0+MCV7zB5lOiRdb5VLKcCHlzUZ5mU+aXH4nyeM3tOgvWvz+dZmGo3ki7SAMf599Ypmea6lWLPl3XKvSZGLAowzmDhXrRtpf2u9SC3hpRbbujTzSjLORj3Rr4mGnAvuyUQK81/iI20HqH/RMTKuiK0O2168yOHuyJ05hTQ== nagios@nagiostest03.*censoreddomainname*.com

(censored the end of the domain because I'd rather not have people knowing where I work...)

It's the same text as the id_rsa.pub file on the server, which also answers lmiltchev's question. Yes, they are indeed identical.