Build Controller Profiling

The build controller supports a pprof profiling mode, which is omitted from the binary by default. To use the profiling, use the controller image that was built with pprof enabled.

Enable pprof in the build controller

In the Kubernetes cluster, edit the shipwright-build-controller deployment to use the container tag with the debug suffix.

kubectl --namespace <namespace> set image \
  deployment/shipwright-build-controller \
  shipwright-build-controller="$(kubectl --namespace <namespace> get deployment shipwright-build-controller --output jsonpath='{.spec.template.spec.containers[].image}')-debug"

Connect go pprof to build controller

Depending on the respective setup, there could be multiple build controller pods for high availability reasons. In this case, you have to look-up the current leader first. The following command can be used to verify the currently active leader:

kubectl --namespace <namespace> get configmap shipwright-build-controller-lock --output json \
  | jq --raw-output '.metadata.annotations["control-plane.alpha.kubernetes.io/leader"]' \
  | jq --raw-output .holderIdentity

The pprof endpoint is not exposed in the cluster and can only be used from inside the container. Therefore, set-up port-forwarding to make the pprof port available locally.

kubectl --namespace <namespace> port-forward <controller-pod-name> 8383:8383

Now, you can setup a local webserver to browse through the profiling data.

go tool pprof -http localhost:8080 http://localhost:8383/debug/pprof/heap

Please note: For it to work, you have to have graphviz installed on your system, for example using brew install graphviz, apt-get install graphviz, yum install graphviz, or similar.