How can I check for repeated strings with check-tail plugin in Sensu?

Question

I am using sensu and the check-tail.rb plugin to alert if any errors appear in my app logs. The problem is that I want the check to be successful if it finds 3 or more error messages.

The solution that I came up with is using a regex like:

\^.*"status":503,.*$.*^.*"status":503,.*$.*^.*"status":503,.*$\im

But it seems to not work because of the match function: instead of passing the variable as a ruby regex it passes it as a string (this can be seen here).

What if you remove the backslashes and use `(?im)^.*"status":503,.*$.*^.*"status":503,.*$.*^.*"status":503,.*$`? — Wiktor Stribiżew, Apr 14 '17 at 06:27
Thanks, that worked. Please answer my question and I will approve it. — Alex Efimov, Apr 14 '17 at 07:00
I added an answer, please check if the ``\`` should be doubled (if you use double quoted string literal, they must be doubled). — Wiktor Stribiżew, Apr 14 '17 at 07:06

score 2 · Accepted Answer · answered Apr 14 '17 at 07:02

2

You need to pass the pattern as a string literal, not as a Regexp object.

Thus, you need to remove the regex delimiters and change the modifiers to their inline option variants, that is, prepend the pattern with (?im).

(?im)\A.*"status":503,.*$.*^.*"status":503,.*$.*^.*"status":5‌03,.*\z

Note that to match the start of string in Ruby, you need to use \A and to match the end of string, you need to use \z anchors.

answered Apr 14 '17 at 07:02

Wiktor Stribiżew

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If you use a double quoted string literal, `\A` and `\z` must be doubled escaped. – Wiktor Stribiżew Apr 14 '17 at 07:10

How can I check for repeated strings with check-tail plugin in Sensu?

1 Answers1