Configure delve debugger for Tekton controller in VSCode. #8876
Description
Summary
While developing the Tekton controller it is sometimes necessary to use the debugger to investigate complex issues. So far this is done mostly via logs.
This is a step by step instruction on how to setup debugging for Tekton controllers.
We can use the following configuration to start the controller with delve enabled:
- comment out the probes in the
controller.yaml
# livenessProbe:
# httpGet:
# path: /health
# port: probes
# scheme: HTTP
# initialDelaySeconds: 5
# periodSeconds: 10
# timeoutSeconds: 5
# readinessProbe:
# httpGet:
# path: /readiness
# port: probes
# scheme: HTTP
# initialDelaySeconds: 5
# periodSeconds: 10
# timeoutSeconds: 5- build the controller with delve using:
ko apply -f config/controller.yaml --debug --disable-optimizations- port forward connections to the controller
kubectl port-forward -n tekton-pipelines pod/tekton-pipelines-controller-XXX-YYY 40000:40000- create a
launch.jsonto connect to delve in the cluster:
{
"version": "0.2.0",
"configurations": [
{
"name": "Attach to Delve (Tekton Controller)",
"type": "go",
"request": "attach",
"mode": "remote",
"port": 40000,
"host": "127.0.0.1",
"apiVersion": 2,
"substitutePath": [
{
"from": "${workspaceFolder}",
"to": "github.com/tektoncd/pipeline"
}
]
}
]
}
- add breakpoints to
pipelinerun.gofor example in thereconcilemethod - attach debugger in VSCode
- run a hello world
PipelineRun
kubectl create -f - <<EOF
apiVersion: tekton.dev/v1
kind: PipelineRun
metadata:
generateName: hello-embedded-run-
spec:
pipelineSpec:
tasks:
- name: hello-task
taskSpec:
steps:
- name: hello-step
image: alpine
script: |
echo "Hello from embedded pipelineSpec!"
EOFAdditional Info
You can change the base image in .ko.yaml for the controller so that you can exec into the controller and investigate the binary which ko created.
baseImageOverrides:
# ...
github.com/tektoncd/pipeline/cmd/controller: cgr.dev/chainguard/go:latest-devWhen you exec into the controller pod, yo can go into the ko-app directory and investigate the binary a bit, then you know what paths the binary uses for the different files where the breakpoints are set.
kubectl exec -it -n tekton-pipelines tekton-pipelines-controller-XXX-YYY -- /bin/shInside the container:
cd ko-app
strings controller | grep pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/clientset/versioned/typed/pipeline/v1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/clientset/versioned/typed/pipeline/v1beta1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/listers/pipeline/v1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/informers/externalversions/pipeline/v1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/listers/pipeline/v1beta1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/informers/externalversions/pipeline/v1beta1/pipelinerun.go
github.com/tektoncd/pipeline/pkg/client/injection/informers/pipeline/v1/pipelinerun/pipelinerun.go
github.com/tektoncd/pipeline/pkg/reconciler/pipelinerun/pipelinerun.goResources
VSCode Go debugging:
- Breakpoint issue: https://github.com/golang/vscode-go/wiki/debugging#my-program-does-not-stop-at-breakpoints
- Ko go build settings
-trimpath: https://ko.build/configuration/#overriding-go-build-settings
Here are some Articles:
- https://pretired.dazwilkin.com/posts/280524
- https://alexsniffin.medium.com/debugging-remotely-in-kubernetes-with-go-fda4f3332316
- https://dchaykin.medium.com/debugging-a-go-service-in-kubernetes-f1dd48865e1d
/kind misc
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