Missing input ID warning is emitted for all inputs when using autodiscover

[belimawr]

The missing input ID warning meant for the Filestream input is being emitted to all inputs without an ID whenever autodiscover is used.

This is just a log warning, the input is started as expected.

• Version: 8.16.1, 8.17.0,
• Operating System: All
• Discuss Forum URL: https://discuss.elastic.co/t/warning-is-observed-huge-number-of-times-input-v2-factory-checkconfig-failed-to-clone-config-before-checking-it-original-config-will-be-checked-it-might-trigger-an-input-duplication-warning-failed-to-get-id-missing-field-accessing-id/374722

Steps to Reproduce:

1. Start Filebeat with the following configuration

   filebeat.autodiscover.providers:
     - type: docker
       hints.enabled: true
       hints.default_config:
         type: log
         paths:
           - /tmp/flog.log
         fields:
           foo: ${data.container.id}
   
   queue.mem:
     flush.timeout: 0
   
   output.discard:
     enabled: true

2. You will see the following warning log

{
  "log.level": "warn",
  "@timestamp": "2025-02-28T16:36:19.405-0500",
  "log.logger": "input",
  "log.origin": {
    "function": "github.com/elastic/beats/v7/filebeat/input/v2/compat.(*factory).CheckConfig",
    "file.name": "compat/compat.go",
    "file.line": 81
  },
  "message": "input V2 factory.CheckConfig failed to clone config before checking it. Original config will be checked, it might trigger an input duplication warning: failed to get 'id': missing field accessing 'id'",
  "service.name": "filebeat",
  "original_config": "{\n  \"fields\": {\n    \"foo\": \"d5062d3af164a2a57d0e9bed5c201dc7a7e0f6814a59665b0973d8fba35fe432\"\n  },\n  \"paths\": [\n    \"/tmp/flog.log\"\n  ],\n  \"type\": \"log\"\n}",
  "ecs.version": "1.6.0"
}

Workaround

While this is just a log warning and the input is still started as expected. The log warning can be ignored or if you want to suppress it, just add and ID to every input. For the example reproducing it will look like:

filebeat.autodiscover.providers:
  - type: docker
    hints.enabled: true
    hints.default_config:
      type: log
      id: foo-bar-${data.container.id}
      paths:
        - /tmp/flog.log
      fields:
        foo: ${data.container.id}

queue.mem:
  flush.timeout: 0

output.discard:
  enabled: true

[botelastic]

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