feat(remap transform): reload transforms with external VRL on SIGHUP

[nekorro]

Summary

On receiving SIGHUP Vector now also reloads transform components with external VRL files.

Vector configuration

./config/config.yaml

sources:
  test-source:
    type: demo_logs
    interval: 2
    format: json

transforms:
  test-embedded-vrl:
    type: "remap"
    source: |-
      .debug = "embedded_01"
    inputs:
      - test-source
  test-external-vrl:
    type: "remap"
    file: "./config/test.vrl"
    inputs:
      - test-source
      
sinks:
  console:
    inputs:
      - test-embedded-vrl
      - test-external-vrl
    target: stdout
    type: console
    encoding:
      codec: json

./config/test.vrl

.debug = "external_01"

How did you test this PR?

1. Run vector with vector -vv -c ./config/config.yaml
2. Ensure that output contains events from both transforms

3. Change content of test.vrl to .debug = "external_01_modified"
4. Change source of test-embedded-vrl to .debug = "embedded_01_modified"
5. Send SIGHUP to vector process
6. Ensure that output contains events from both transforms with modified values

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

• Closes: Vector does not reload vrl file #23820

Notes

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