Extract number from log line (json)

Grafana
1

Hi there, i am starting to understand how to display data in grafana. i have a log comming in from loki where i need to extract a string from a json value.

for now i got this far:

{container_name=~".*selfs.*"} |= has completed in | json | line_format "{{.msg}}"

this gives me a log line like this for example:

Job Nr: 6, ID: 4t9UV3ngr5_0mu4toV8UB has completed in 46.05699282288551 seconds!

what do i need to do t just get the seconds out of this? i played around with pattern and regex, but nothing seems to work.

is this possible?

Thank you so much,

pcace

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2

You need parser, e.g. pattern

1 Like
3

but in this case:

Job Nr: 18, ID: DOpEoCQh0UCj7Pop6SBpZ has completed in 64.88847192001343 seconds!

how would a pattern look like to extract seconds? I am really having trouble to understand the documentation there.

i tried variations of this:

{container_name=~".*selfs.*"} 
|= `has completed in` #
| pattern `<_>has completed in <seconds>` 
| line_format "seconds = {{.seconds}}"

or this:

{container_name=~".*selfs.*"} 
|= "has completed in" 
| pattern `Job Nr: <_>, ID: <_> has completed in <seconds> seconds` 
| line_format "seconds = {{.seconds}}"

but without any success

Thanks a lot

1 Like
4

With regex is should be like this:

{container_name=~".*selfs.*"} 
|= "has completed in" 
| regexp "has completed in (?P<seconds>[\\d\\.]*) seconds" 
| line_format "seconds = {{.seconds}}"

A pattern requires to match the full line, it looks like you missed the ! at the end of the line.

5

Hi, thank you so much for your reply. I just cannot get my head around why this is working.
why is \d\ not the literal caracter ā€œdā€ ? like here: regex101: build, test, and debug regex

or what kind of regex is grafana using here?

Thanks a lot for help!

6

Grafana uses the Golang RE2 syntax, see

\d for digits
\. to match the dot as well

But you have to escape an \, therefor the double \\

I updated your regex, see https://regex101.com/r/M5ATsH/2