feat(config): Add support for v1.1 protocol of secrets exec backend

[graphcareful]

Summary

The exec backend within the secrets framework works to fetch secrets by execing a provided path to a binary and communicating with it over a simple (but established) protocol. This protocol is versioned and currently Vector only supports 1 version.

This PR introduces support for v1.1. An example of a program that is compliant with these new changes is the datadog-secrets-backend specifically the changes in the v1 branch which will eventually become part of the new standard.

The main changes to Vector were to include the backend configuration with each request to this binary. This means opening up new configuration options to the secrets global option.

Vector configuration

secret:
  exec_backend:
    type: "exec"
    command: [/usr/bin/datadog-secret-backend]
    protocol:
      version: v1_1
      backend_type: file.json
      backend_config:
        file_path: ~/secrets.json

sources:
  agent:
    type: "datadog_agent"
    address: 0.0.0.0:8282
    log_namespace: true

sinks:
  out:
    inputs:
      - "agent"
    type: "datadog_logs"
    default_api_key: SECRET[exec_backend.dd_logs_api_key]

How did you test this PR?

Using the config about and building the datadog-secrets-backend from source.

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

Notes

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[emilychendd]

LGTM

[pront]

thanks!