topic Re: Use of placeholder for automatically applied tags (host names) in Open Q&A

Use of placeholder for automatically applied tags (host names)

urs_fischer — Wed, 28 Sep 2022 09:41:37 GMT

I have a problem with automatically applied tags. I guess it's a simple question, and yet I can't figure it out. We have a special name convention for our server names. The second digit of the host name means the stage in which the server is located (production, pre-procurement, etc.). Is it possible to create an automatically applied tag rule based on the hostname, depending on the value of the second digit of the host?
Example hostname: S45002134A (second character "4" means pre-production)

To create the rule:

- Rule applies to: "hosts"

- Condition: "Hostname" "begins with" (or "contains")

What needs to be entered in the field? I need kind of a placeholder for the first digit because the it changes based on other conditions.

Re: Use of placeholder for automatically applied tags (host names)

dave_mauney — Thu, 09 Jan 2020 17:27:15 GMT

I would try "contains regex" with ".4" as your condition. You can set the "optional tag value" to "pre-production" for this example and replicate the rule for other environments.

Re: Use of placeholder for automatically applied tags (host names)

justin_hogue — Thu, 09 Jan 2020 17:35:06 GMT

Rule applies to: "hosts"

Condition: "Host name" "contains regex"

Value: ^.{1}[4]

This might also work. It should match the second character of a string depending on what is in the square brackets.

Re: Use of placeholder for automatically applied tags (host names)

urs_fischer — Fri, 10 Jan 2020 09:52:05 GMT

Thanks for your help. It looks like i have to read more about regex 🙂

Re: Use of placeholder for automatically applied tags (host names)

ctturner — Fri, 10 Jan 2020 13:14:56 GMT

@Urs F. Use this Regex link to test out Regex code. I used this when I was learning Regex to ensure the code was defined correctly.

Regex101

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Tue, 04 Jun 2024 04:44:42 GMT

Hi Justin

How to do tagging if 3rd last character of hostname in 3 or 5.,

auszvrcuw333 - how to do regex if 3rd last character of hostname in 3 or 5, tagging it as staging.

Thanks

Sundar.v

Re: Use of placeholder for automatically applied tags (host names)

paulo_calaxa — Tue, 04 Jun 2024 06:55:53 GMT

Hi.
For instance, you may confirm that it accepts and works as intended:

[3|5]\d{2}$

given the following strings, it will only match the ones ending in digits, with 3 or 5 in the 3rd last place:
auszvrcuw33z
auszvrcuw333

auszvrcuw446
auszvrcuwa46
auszvrcuw3z3
auszvrcuw33a
auszvrcuw346
auszvrcuw546

normal characters? substitute the "d" for a "w"
Any character? substitute the "\d" for a "."
You may test it in https://regex101.com/
and it also as examples/help, at the lower right corner

Kind regards,
Paulo

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Sun, 09 Jun 2024 07:56:50 GMT

Hi URU

Please share screenshot of how you have done this in automatic applied tags?. Please find my screenshot . i am still finding where to add to rule for to match hostname condition.

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Sun, 09 Jun 2024 08:11:35 GMT

when is use this [3|5]\d{2}$, i am getting only the names whose lastletter is 5, not 3.

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Sun, 09 Jun 2024 08:27:14 GMT

This is the issue., Since there is hostname is matching - what we do if 10th of hostname is 5 or 3.

Windows name - auszvrcuw346.rcuad.local

Unix name - auszvrcuw346

Re: Use of placeholder for automatically applied tags (host names)

AntonPineiro — Sun, 09 Jun 2024 15:02:20 GMT

Same question answered here.

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Tue, 15 Oct 2024 03:45:58 GMT

Hi Paulo

above solution worked for ones ending in digits, with 3 or 5 in the 3rd last place.

How do i add one more condition so that it picks up when hostname starts with aus

Re: Use of placeholder for automatically applied tags (host names)

sundarv1 — Tue, 15 Oct 2024 03:57:47 GMT

please find the attached one. when i put the and condition to have hostname start with auu - it is not giving actual result