PromTail JSON Scrape Special Character

Question

For a PromTail scrape config, I am using a JSON stage.

I have a JSON log that looks like this:

{
   "@l": "info",
   "foo": "bar"
}

I am looking to use the JSON stage to extract the @l property into the map.

I tried this:

- json:
     expressions:
       level: '"@l"'
- labels:
     level:

The agent starts but no logs are scraped. If I remove the JSON stage, tons of logs come in.

What could I be doing wrong with the @ escape sequence?

score 1 · Accepted Answer · answered Feb 06 '22 at 03:36

I have confirmed. To escape a @ or ., you use double quotes.

so examples:

{
   "@l": "Debug",
   "foo.bar": "value"
}

'"@l"'

or

'"foo.bar"'

Using a JMESPath Literal

This pipeline uses a literal JMESPath expression to parse JSON fields with special characters in the name, like @ or .

1 Answers1