How to get the hostname during a check execution

[simonm (Simon)]

Hi,

how is it possible to determine the host a check is currently running against?
I have found this thread here - but it does not contain the answer.
Thanks & regards,
Simon

[r.sander (Robert Sander)]

In checkmk 1.6 there is a global method host_name() available. I think you have to import it from somewhere in 2.0, because it is not in the official plugin API.

[ChristianM (Christian Michaelski)]

Hi Simon,
you can try to get this information by using the livestatus query.You can filter the check and get all hosts involved. Or ist this to simple?
Cheers,
Christian

[simonm (Simon)]

Hi,

thanks for your replies.
@r.sander (Do you know from where the host_name function can be imported?)
@ChristianM I don’t think that a livestatus query can give me the host that a check is currently working on.

Perhaps I should explain what I want to achieve: access the HTML logs / error logs (red dot icon) of Robot Framework (stored on disk) from a custom action icon.

Robot logs must be stored in the context of the suite name and the host the suites run on:

OMD[cmk]:~/local/share/addons/robotmk/win10simdows$ ls
-rw-rw---- 1 cmk cmk    0 Aug  2 08:01  e2e_app_error_log.html
-rw-rw---- 1 cmk cmk    0 Aug  2 08:01  e2e_app_log.html

The connection between service names and the RF suite would be symlinked:

OMD[cmk]:~/local/share/addons/robotmk/win10simdows$ tree
.
├── Robot Framework E2E GetReport      # << cmk service
│   ├── last_suite_error_log.html -> ../e2e_app_error_log.html
│   └── last_suite_log.html -> ../e2e_app_log.html
├── Robot Framework E2E Login          # << cmk service
│   ├── last_suite_error_log.html -> ../e2e_app_error_log.html
│   └── last_suite_log.html -> ../e2e_app_log.html
├── Robot Framework E2E Logout         # << cmk service
│   ├── last_suite_error_log.html -> ../e2e_app_error_log.html
│   └── last_suite_log.html -> ../e2e_app_log.html
├── e2e_app_error_log.html          # << RF log
└── e2e_app_log.html                # << RF log

In the end, the links behind the log icons could look like this:

http://cmksrv/cmk/addons/robotmk/HOSTNAME/SERVICEDESC/last_suite_log.html
http://cmksrv/cmk/addons/robotmk/HOSTNAME/SERVICEDESC/last_suite_error_log.html

---

As said, the problem is that the discovery / check must know the current host name in order to descend into the correct host directory.

Any ideas?

Thanks a lot…

/Simon

[mike1098 (Michael FRANK)]

Hi Simon,

We did something similar for a web/icon plugin. The function is defined like this:

def paint_my_link(what, row, tags, host_custom_vars ):

And the host finally like this:

HOST=row["host_name"]

Let me know in case of you want to see the complete code. I will send by mail.

BR

Michael

[ChristianM (Christian Michaelski)]

Hi Simon,
why did you store the results in local/share/addons? As an idea, you can also store this results directly in document_root of omd site. This makes it easy to point directly to the html results like custom notes.
In path ~/local/share/check_mk/web/htdocs you create your result files as you described before.
Then you can call the Results by "/$HOSTNAME$/$SERVICEDESC$/last_suite_log.html
I hope this idea is helpful.
Cheers,
Christian

[simonm (Simon)]

Hi @ChristianM ,

thanks for the hint.
In general a good idea, were it not for the directive allow from all:

Alias /cmk/check_mk/local /omd/sites/cmk/local/share/check_mk/web/htdocs
<Directory /omd/sites/cmk/local/share/check_mk/web/htdocs>
      Order deny,allow
      allow from all
</Directory>

Even if Robot Framework masks (almost…) all secrets, the logs should not be available for non-authenticated users.
Regards,
Simon

[moritz]

Hi Simon,
This won’t help you, but it is the “official” answer to your question:
You cannot access the host name during the discovery or check execution. Calls to “host_name” and the like are left-overs of the old API and may stop working anytime.

[simonm (Simon)]

Hi Moritz,

thanks for the info, even if it’s rather bad
I will add a hostname dropdown field to the HTML log option in WATO (similar to piggyback), where the log can be assigned to a host. If unchecked, the host machine name gets used.

Regards,
Simon

[r.sander (Robert Sander)]

I have the need to know the name of the current host in one of my extensions.

I do this: from cmk.base.check_api import host_name in checkmk 2.0

The extension is this one: check_mk_extensions/updater_hostname at cmk2.0 · HeinleinSupport/check_mk_extensions · GitHub

I need to compare the name of the host with the name that was used when registering the agent updater to detect errors after cloning VMs. How would I implement such a check without host_name()?

There may be other use cases where the current host name is important for the check. Do we really have to fall back to active checks with $HOSTNAME$ as argument in these situations?