Question: best way to set PrometheusExporter._serializer._appendTimestamp = false

[antoniomrfranco]

• This only affects the JavaScript OpenTelemetry library
• This may affect other libraries, but I would like to get opinions here first

Hello everyone,

I'd like to set _appendTimestamp to false for a PrometheusSerializer instance that is part of a PrometheusExporter object.

I saw that PrometheusSerializer has a property named _appendTimestamp which is defined in its constructor:

opentelemetry-js/packages/opentelemetry-exporter-prometheus/src/PrometheusSerializer.ts

Lines 141 to 146 in 3f72613

	constructor(prefix?: string, appendTimestamp = true) {
	if (prefix) {
	this._prefix = prefix + '_';
	}
	this._appendTimestamp = appendTimestamp;
	}

Also, I saw that the only place where PrometheusSerializer is instantiated is in the constructor method of PrometheusExporter:

opentelemetry-js/packages/opentelemetry-exporter-prometheus/src/PrometheusExporter.ts

Line 59 in 3f72613

this._serializer = new PrometheusSerializer(this._prefix);

However, as PrometheusExporter instantiates PrometheusSerializer passing prefix only, I can't control the value of appendTimestamp.

Is there any way to set appendTimestamp to false in this case?

Thanks.

[dyladan]

I think this is just a bug. If you want to take a crack at fixing it, I suggest allowing an options object to the PrometheusExporter constructor.

/cc @legendecas any chance you can take this if @antoniomrfranco doesn't have time?

[antoniomrfranco]

Thanks for the prompt response, @dyladan .
I just created a PR that fixes this issue: #1697.

[legendecas]

Closing as the related PR is already landed. Thank you for the work on this!