Add OTEL tracing support for Wiremock + automatic OTEL for Aspire integration

[petrroll]

Adds optional tracing instrumentation and OTEL export support for WireMock server

Adds optional (based on config) instrumentation for frameworks that support Activity API:

• Custom WireMock DT/Activity instrumentation that's part of WireMock middleware
• ASP.NET DT/Activity http.server instrumentation for WireMock ASP.NET server (not implemented for OWIN)

Adds inbuild OTEL exporter for WireMock ASP.NET server
Adds ability to propagate the OTEL/DT config when server is run from command line (should get picked up by Docker container when build)
Adds config surfaces for Aspire integration (requires new container version)

Based on #1418

References

Fixes #1214

Submitter checklist

• Recommended: Join WireMock Slack to get any help in #help-contributing or a project-specific channel like #wiremock-java
• The PR request is well described and justified, including the body and the references
• The PR title represents the desired changelog entry
• The repository's code style is followed (see the contributing guide)
• Test coverage that demonstrates that the change works as expected
• For new features, there's necessary documentation in this pull request or in a subsequent PR to wiremock.org

Tests & documentation not yet updated, will do if we agree it's possible to eventually merge it.

[petrroll]

I also thought about updating the docker repo but I'm super confused by the two projects there, the local on older version and non local.

[petrroll]

For now it's just traces. But metrics and logs should be super easy. Though the logging in the project is tad non-simple and mildly custom so I'm not super sure.

[petrroll]

I also see there's version 2 and I didn't check how much it uses the same things. But if nothing this PR should show it it can be transplanted / implemented there.

[StefH]

I also thought about updating the docker repo but I'm super confused by the two projects there, the local on older version and non local.

My docker project is here: https://github.com/wiremock/WireMock.Net-docker
But I don;t think you need to change something there.

---

However, maybe you mean the Testcontainers project?
https://github.com/wiremock/WireMock.Net/tree/master/src/WireMock.Net.Testcontainers
That project could also have OTEL I think?

[StefH]

Thanks for the PR!

[StefH]

For now it's just traces. But metrics and logs should be super easy. Though the logging in the project is tad non-simple and mildly custom so I'm not super sure.

Metrics is maybe not needed.

By logs, you mean the normal logs?
So implementing IWireMockLogger ?

[StefH]

I also see there's version 2 and I didn't check how much it uses the same things. But if nothing this PR should show it it can be transplanted / implemented there.

First I will merge this to the normal 1.x version, and then I can merge it into 2.x and hope it's easy to do...

[petrroll]

I also thought about updating the docker repo but I'm super confused by the two projects there, the local on older version and non local.

My docker project is here: https://github.com/wiremock/WireMock.Net-docker But I don;t think you need to change something there.

However, maybe you mean the Testcontainers project? https://github.com/wiremock/WireMock.Net/tree/master/src/WireMock.Net.Testcontainers That project could also have OTEL I think?

No I meant that one, as you still need to at least bump the version there. Good point about test containers tho.

[StefH]

I also thought about updating the docker repo but I'm super confused by the two projects there, the local on older version and non local.

My docker project is here: https://github.com/wiremock/WireMock.Net-docker But I don;t think you need to change something there.
However, maybe you mean the Testcontainers project? https://github.com/wiremock/WireMock.Net/tree/master/src/WireMock.Net.Testcontainers That project could also have OTEL I think?

No I meant that one, as you still need to at least bump the version there. Good point about test containers tho.

1. Yes, I need a new version also when this one is finished.
2. If it's easy, add OTEL to Testcontainers , else make a new PR after this one is merged to main.

[petrroll]

@StefH please check now, reworked in split way (OTEL vs Activity tracing), and I think it should be fine :). We'll just need to update the docker image executable to use the package and set the OTEL part up.

[StefH]

@petrroll do you have time to complete all PR comments?

[petrroll]

Last few days were a bit hectic, I'll try to take a proper final look tomorrow.

…

--- Best regards *Petr Houška* http://petrroll.cz

On Sat, Jan 17, 2026, 11:39 Stef Heyenrath ***@***.***> wrote: *StefH* left a comment (wiremock/WireMock.Net#1418) <#1418 (comment)> @petrroll <https://github.com/petrroll> do you have time to complete all PR comments? — Reply to this email directly, view it on GitHub <#1418 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AANO24LX2BWMGP6YNJUVM5T4HIGNLAVCNFSM6AAAAACRGQJYOGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTONRTGAZDCNJUGM> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[petrroll]

@StefH I've fixed all/most comments (one I don't think I should act upon) + added tests.

[petrroll]

If it's good as is, I'll update the docs and then we can merge both.

[StefH]

@petrroll
This is merged to main and I created a new NuGet