telemetry: parsing v0.2.0 configuration causes loss of default settings

[codeboten]

Component(s)

service

What happened?

Describe the bug

A bug was introduced in 4edaacd which causes default values to be ignored.

Steps to reproduce
Update collector to v0.119.0+ and use a configuration that triggers the codepath to parse the config using the old config schema (headers using a map instead of a list of key/value pairs, see collector config)

What did you expect to see?
Collector start as before

What did you see instead?
The following error:

2025/02/19 14:06:59 collector server run finished with error: failed to create logger: no encoder name specified

Collector version

v0.119.0+

Environment information

Environment

OS: (e.g., "Ubuntu 20.04")
Compiler(if manually compiled): (e.g., "go 14.2")

OpenTelemetry Collector configuration

service:
  telemetry:
    logs:
      level: debug
      processors:
        - batch:
            exporter:
              otlp:
                protocol: http/protobuf
                endpoint: collector:4318
                headers:
                  key1: value1

Log output

2025/02/19 14:06:59 collector server run finished with error: failed to create logger: no encoder name specified

Additional context

No response

[codeboten]

A workaround is to update the configuration to the following:

service:
  telemetry:
    logs:
      level: debug
      processors:
        - batch:
            exporter:
              otlp:
                protocol: http/protobuf
                endpoint: collector:4318
                headers:
                  - name: key1
                    value: value1