How to filter out given query parameter in http client?

[yulin-li]

In our scenario, some authentication fields are put in the http query parameter. Is there some custom filter I can use to remove these query parameters in the URL when uploading traces?

Thanks.

[dmathieu]

The net/http transport injects attributes from the HTTP request here: https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/net/http/otelhttp/transport.go#L113
Within this HTTPClientAttributesFromHTTPRequest method, the HTTP URL (which is where I suppose your query string is added) gets appended here: https://github.com/open-telemetry/opentelemetry-go/blob/5568a3072367bb8ac4d2d9e759e7deb5a975b9f5/semconv/internal/http.go#L161

None of those method allow for filtering to skip some of the attributes.
So the only way you can currently do this would be with a custom transport that you run on top of the net/http one provided for tracing, which would modify/nullify the http.url attribute and remove the sensitive data you don't want there.

[yulin-li]

Thanks for the quick response. I will try to build a custom transport for this.

But I think it's a common scenario, would you consider putting this feature request in the backlog?

[dmathieu]

How about an option WithURLSanitizer(func(*net.URL) *net.URL)) which would give you the original URL, and let you do any sanitization you want?

[yulin-li]

That would be great

[dmathieu]

Actually, the approach in open-telemetry/opentelemetry-go#2794 may be better for you.