[pkg/ottl] Support string to boolean conversion.

[danelson]

Component(s)

pkg/ottl

Is your feature request related to a problem? Please describe.

Original discussion in https://cloud-native.slack.com/archives/C01N6P7KR6W/p1764961932853649.

I would like to be able to convert some boolean like strings to booleans. Something that improves the following

transform/string_to_boolean:
  log_statements:
    - statements:
      - set(log.attributes["my.attribute"], true) where ToLowerCase(log.attributes["my.attribute"]) == "true"
      - set(log.attributes["my.attribute"], false) where ToLowerCase(log.attributes["my.attribute"]) == "false"

Describe the solution you'd like

A function such as ParseBool which takes inspiration from ParseInt. It could work on non string objects as well. The syntax could look like

transform/boolean:
  log_statements:
    - statements:
      - set(log.attributes(["my.attribute"]), ParseBool(log.attributes["my.attribute"])

for my string specific case I would expect something like

transform/boolean:
  log_statements:
    - statements:
      - set(log.attributes(["my.attribute"]), ParseBool(log.attributes["my.attribute"]) where IsString(log.attributes["my.attribute"])

Describe alternatives you've considered

No response

Additional context

If this is something the maintainers feel like supporting I can contribute a PR

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[github-actions]

Pinging code owners:

• pkg/ottl: @TylerHelmuth @evan-bradley @edmocosta

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[edmocosta]

Thanks for opening this issue, I support adding a function for that.

I'd say this converter is similar to the existing String, Int and Double -like converters, so I'd follow the same pattern and add the Bool(value) converter.

OTTL already supports this conversion thought the ottl.BoolLikeGetter argument (used on the IsBool), which makes this function implementation very simple.

[TylerHelmuth]

One alternative I want to throw out there, does this work?

transform/string_to_boolean:
  log_statements:
    - statements:
      - set(log.attributes["my.attribute"], ToLowerCase(log.attributes["my.attribute"]) == "true")

[edmocosta]

One alternative I want to throw out there, does this work?

transform/string_to_boolean:
  log_statements:
    - statements:
      - set(log.attributes["my.attribute"], ToLowerCase(log.attributes["my.attribute"]) == "true")

I tried that as well, but it seems the grammar does not support it.

[danelson]

For completeness, the error I see is

2025/12/10 18:15:20 collector server run finished with error: invalid configuration: processors::transform/string_to_boolean: unable to infer a valid context (["resource" "scope" "log"]) from statements ["set(log.attributes["my.attribute"], ToLowerCase(log.attributes["my.attribute"]) == "true")"] and conditions []: statement has invalid syntax: 1:81: unexpected token "==" (expected ")" Key*)