...
Agent controller - Connection refused
Problem
With Checkmk 2.1, we released the new agent controller with a TLS connection. Detailed docs can be found here:
...
In this manual, we will show you how to debug the below error:
...
.png?version=1&modificationDate=1653568942260&cacheVersion=1&api=v2&width=800)
...
Please run the following commands to check the state of the agent controller and the port states:
...
Disable TLS registration on the CMK Server: Properties of host → menu → entry Host → Remove TLS registration
Afterwards Afterward, ss should show xinetd claiming the connection
...
After installing the agent, the registration is not working and showing the following issue:
...
Solution
Please check and verify that the agent controller is running:
| Code Block | ||||
|---|---|---|---|---|
| ||||
ss -tulpn | grep 6556 ps waux | grep cmk-agent-ctl cmk-agent-ctl status systemctl status check-mk-agent.socket systemctl status cmk-agent-ctl-daemon.service |
In that case here, the agent controller is not running because xinetd is running. For the agent controller, systemd is necessary: https://checkmk.com/werk/13865
If you're using the bakery, you need to create the following rule:
...
...
Without the bakery, please follow these steps: https://docs.checkmk.com/latest/en/agent_linux_legacy.html#_systemd
...
| Code Block | ||
|---|---|---|
| ||
root@<cmkserver>:~# cmk-agent-ctl register -H <host> -s <checkmk-server> -i <site> -U <username> -p:8000 |
Solution #2
Add the self-signed certificate to the OS's cert store. Example for Ubuntu: https://ubuntu.com/server/docs/security-trust-store
...
If you see this error message when trying to work with any subcommand of cmk-agent-ctl, there is probably something wrong in with the file /var/lib/cmk-agent/registered_connections.json.
Solution
First, move the file registered_connections.json to registered_connections.json.bak and re-run the command. If that works, you can start checking the content of the file. If you still need the registration data stored in the file, check the line and column in the error message and try to repair it. If you don't need it anymore, simply delete the file.
Related articles
...