OTTL int to hex conversion function

[krokwen]

Component(s)

pkg/ottl

Is your feature request related to a problem? Please describe.

I'm unable to convert uint64 trace/span id to proper hex value during logs parsing

Describe the solution you'd like

Function name "Hex" that will accept two arguments:

1. Int value
2. total length in bytes

second parameter is required to prepend the string with zeros to get the hex string of fixed length (trace_id.string and span_id.string accept only 32 char hex string, i'e 16-bytes)

Example:

# attributes['dd_trace_id']="13498527101626869733"
processors:
  transform:
    error_mode: ignore
    log_statements:
      - context: log
        statements:
          - set(trace_id.string, Hex(Int(attributes["dd_trace_id"]), 16))
# trace_id.string now is "0000000000000000bb5466e17373e7e5"

Describe alternatives you've considered

1. I tried to convert trace id to hex on the PHP-side
   It's not possible due to PHP is using signed int64, and in result a lot of trace ids become '7fffffffffffffff' when I trying to dechex((int) $ddTraceId)

2. The newer DDTrace (0.94+ or 0.96+) provides a method to acquire hex trace id (without leading zeros), but the newer extension breaks up my whole app for no reason (broken read from .env file...)

Additional context

Our laravel-based project uses DDTrace PHP-extension (0.88.1) for tracing purposes.
I can get traces easily using receiver/datadogreceiver (it processes trace_id internally by it's own)
But when I trying to parse application logs I have an issue with parsing of the datadog trace id which comes as uint64 that I unable to convert to hex value and write it as trace_id.string.

[github-actions]

Pinging code owners:

• pkg/ottl: @TylerHelmuth @kentquirk @bogdandrutu @evan-bradley

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[TylerHelmuth]

@krokwen what are you using to collect the datadog logs that have a trace_id that is an uint64?

[krokwen]

It's not me, but our dev's =) and it's not a datadog logs, just regular app logs, json-serialized, including current trace and span IDs

It's done like this in our Logging\DatadogHandler

$context = \DDTrace\current_context();
$record->extra['dd'] = [
  'trace_id' => $context['trace_id'],
  'span_id' => $context['span_id'],
];

I tried to poke a stick into it, examined few methods like \DDTrace\root_span() or \DDTrace\active_span() and didn't found there any hex-like notation, only stringified long integers

[krokwen]

->hexId() method is not available in my version of DDTrace, as I said before, the newer version breaks up the whole app...

[TylerHelmuth]

The OTTL grammar supports Byte Slices, represented as hex strings such as 0x0001. A Converter like Hex would act similar to other Converters like String or Int where it takes a single input and attempts to convert it to the new type. So Hex(13498527101626869733) would return a byte slice represented by 0xBB5466E17373E7E5. Ultimately we'd want to be able to pass that value to https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/pkg/ottl/ottlfuncs/README.md#traceid

[crobert-1]

Looks like from what Tyler suggested this is a valid enhancement request, removing needs triage. (Let me know if I misunderstood though.)

[odubajDT]

Hi, I would like to work on this issue cc @evan-bradley