Public key authentication failed: Username/PublicKey combination invalid

[LipstickLinux]

Good morning/afternoon/evening, all.

I inherited a Zabbix (v3.2.6 on RHEL 7.3) monitoring environment and am tasked with creating an action for restarting a service on a triggering host. I have created an Action Operation using SSH to run the commands on the host, but I don't like the password method of connecting. (It worked when I tested it, but the password is not cloaked, and I don't want it seen.)

I am trying to use the public key method, therefore. So, I took these steps to make that happen:
- Created, chown'ed, and chmod'ed the zabbix user's home directory at /var/lib/zabbix.
- Ran ssh-keygen to create the key pair.
- Modified /etc/zabbix/zabbix_server.conf to point it to /var/lib/zabbix/.ssh.
- Used ssh-copy-id to copy the public key to the affected host.
- Configured the operation (within the action) to connect via the "zabbix" user and provided id_rsa.pub and id_rsa as the public and private keys, resp.
- Killed the service I was testing (apache2) on the affected host.

The action fired, and the error I received was that in the subject, "Public key authentication failed: Username/PublicKey combination invalid".

I've searched the web and searched these forums and cannot find what I'm doing wrong. Would appreciate some help, if you can provide it.

Thanks in advance!

[tamas-p]

Hi,

I have the very same issue. I have followed the 3.4 documentation step-by-step, and all I've got is Public key combination invalid.

https://www.zabbix.com/documentation/3.4/manual/config/items/itemtypes/ssh_checks

If I take over the zabbix user, and run ssh root@target it, logs in fine as root.
Looking at the target's log, it does try to login as zabbix user rather than root.
Why the official documentation say "sudo -u zabbix ssh-copy-id [email protected]" if the system wouldn't do the root at the first place?
How do I set the username here for the target?
I have tried the key like this: ssh.run[test1,root@target,22,utf-8]
But same issue.
It is fairly problematic for me to create a "zabbix user" on the target system... would be great if I could use this with some existing user....

Thanks

[tamas-p]

Ok, apparently I haven't seen there is a user field when I select the Public key version of ssh during the item setup...
It is working now.