Jaeger Tracing Tutorial
Zuul includes support for distributed tracing as described by the OpenTelemetry project. This allows operators (and potentially users) to visualize the progress of events and queue items through the various Zuul components as an aid to debugging.
Zuul supports the OpenTelemetry Protocol (OTLP) for exporting traces. Many observability systems support receiving traces via OTLP. One of these is Jaeger. Because it can be run as a standalone service with local storage, this tutorial describes how to set up a Jaeger server and configure Zuul to export data to it.
For more information about tracing in Zuul, see Tracing.
To get started, first run the Quick-Start Installation and Tutorial and then follow the steps in this tutorial to add a Jaeger server.
Restart Zuul Containers
After completing the initial tutorial, stop the Zuul containers so that we can update Zuul’s configuration to enable tracing.
cd zuul/doc/source/examples sudo -E docker-compose -p zuul-tutorial stop
Restart the containers with a new Zuul configuration.
cd zuul/doc/source/examples ZUUL_TUTORIAL_CONFIG="./tracing/etc_zuul/" sudo -E docker-compose -p zuul-tutorial up -d
This tells docker-compose to use these Zuul config files.
The only change compared to the quick-start is to add a
tracing section to
[tracing] enabled=true endpoint=jaeger:4317 insecure=true
This instructs Zuul to send tracing information to the Jaeger server we will start below.
A separate docker-compose file is provided to run Jaeger. Start it with this command:
cd zuul/doc/source/examples/tracing sudo -E docker-compose -p zuul-tutorial-tracing up -d
You can visit http://localhost:16686/search to verify it is running.
Recheck a change
Visit Gerrit at http://localhost:8080/dashboard/self and return to the
test1 change you uploaded earlier. Click Reply then type
recheck into the text field and click Send. This will tell Zuul
to run the test job once again. When the job is complete, you should
have a trace available in Jaeger.
To see the trace, visit http://localhost:16686/search and select the zuul service (reload the page if it doesn’t show up at first). Press Find Traces and you should see the trace for your build appear.
distributed tracing: https://opentelemetry.io/docs/concepts/observability-primer/#distributed-traces