[pkg/ottl]: func_replace_all_patterns does not work with log body string

[jsirianni]

Component(s)

No response

What happened?

Description

Log bodies can be a string or a map. The func_replace_all_patterns works when body is a map, but does not work when body is a string.

Steps to Reproduce

Configure the collector to read a log file without parsing. This will result in a string body.

Use the Transform processor + replace_all_patterns to replace a sub string. In my example, I have an escaped json string that I want to remove the \ from. {\"key\":\"value\"} --> {"key":"value"}.

transform/remove-escape:
  error_mode: ignore
  log_statements:
    - context: log
      statements:
        - replace_all_patterns(body, "value", "\\\\", "")

Expected Result

Because body can be a string, I would expect ottl functions to support them.

Actual Result

It works if my log message is at body.message but does not work if it is at body (string).

Alternatives Considered

I wrote an ottl function that wraps strings.ReplaceAll(). It supports the operation I am performing. I suspect this function would not be accepted as it overlaps with replace_all_patterns.

Collector version

v0.111.0

Environment information

Environment

OS: Debian 12
Compiler: Go 1.22.6

OpenTelemetry Collector configuration

No response

Log output

No response

Additional context

No response

[github-actions]

Pinging code owners:

• pkg/ottl: @TylerHelmuth @kentquirk @bogdandrutu @evan-bradley

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[TylerHelmuth]

The func_replace_all_patterns works when body is a map, but does not work when body is a string.

Yes, this is by design. If you want to replace the the characters in a single string use replace_pattern