[processor/transformprocessor] Unexpected behaviour when setting resource attributes

[tarokkk]

Component(s)

processor/transform

What happened?

Description

Only the last event record change will be persistent when modifying a resource attribute on a log record.

Steps to Reproduce

Set up a file log receiver and use a transport processor in the pipeline like this:

      transform/example:
        log_statements:
          - conditions: null
            context: log
            statements:
              - set(resource.attributes["vhost"],attributes["example"])

The file log receiver "sometimes" emits the logs in "batches" with the same resource "header"

Expected Result

log1 Resource{"vhost": "xxx"}, Log{"example": "xxx"}
log2 Resource{"vhost": "yyy"}, Log{"example": "yyy"}

Actual Result

log1 Resource{"vhost": "yyy"}, Log{"example": "xxx"}
log2 Resource{"vhost": "yyy"}, Log{"example": "yyy"}

I assume that the setter does not clone the resource & scope part on modification which makes the individual log records to overwrite each resource context.

Collector version

0.104.0

Environment information

Environment

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

OpenTelemetry Collector configuration

No response

Log output

No response

Additional context

No response

[github-actions]

Pinging code owners:

• processor/transform: @TylerHelmuth @kentquirk @bogdandrutu @evan-bradley

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[TylerHelmuth]

This looks like a duplicate of #32080. Check if https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/processor/transformprocessor/README.md#transformflattenlogs solves your issue. Please ping me if you think this is different.