contextual logging: update plans and status

We need to be more conservative than originally planned and continue to produce
the same informative log output as before when contextual logging is disabled.

To help reviewers understand the scope of the work, a new "Status and next
steps" summarizes where we are with the conversion.

Author: pohly

keps/sig-instrumentation/3077-contextual-logging/README.md

@@ -53,6 +53,7 @@
   - [Scalability](#scalability)
   - [Troubleshooting](#troubleshooting)
 - [Implementation History](#implementation-history)
+- [Status and next steps](#status-and-next-steps)
 - [Drawbacks](#drawbacks)
 - [Alternatives](#alternatives)
   - [Per-component logger](#per-component-logger)
@@ -520,9 +521,8 @@ logger.Info("Processing", "pod", klog.KObj(pod))
 logger.Info("Done", "pod", klog.KObj(pod))
 ```
 
-Starting with beta, the feature gate will be enabled and code can be written
-without such duplication to avoid the need for further changes when reaching
-GA:
+Starting with GA, the feature will always be enabled and code can be written
+without such duplication:
 
 ```
 logger := logger.WithValues("pod", klog.KObj(pod))
@@ -1075,14 +1075,130 @@ None besides bugs that could cause a program to panic (null logger).
 
 ###### What steps should be taken if SLOs are not being met to determine the problem?
 
-Revert commits that changed log calls.
+A cluster operator can disable the feature via the feature gate.
+
+Kubernetes developers can revert individual commits that changed log calls once
+it has been determined that they introduce too much overhead.
 
 ## Implementation History
 
 * Kubernetes 1.24: initial alpha
 * Kubernetes 1.27: parts of kube-controller-manager converted
 * Kubernetes 1.28: kube-controller-manager converted completely, relationship
   with log/slog in Go 1.21 clarified
+* Kubernetes 1.29: kube-scheduler converted completely
+
+## Status and next steps
+
+As of Kubernetes 1.29.1, kube-controller-manager and kube-scheduler have been
+converted. The logcheck tool can be used to count remaining log calls that need
+to be converted:
+
+```
+go install sigs.k8s.io/logtools/logcheck@latest
+
+echo "Component | Non-Structured Logging | Non-Contextual Logging " && echo "------ | ------- |  -------" && for i in $(find pkg/* cmd/* staging/src/k8s.io/* -maxdepth 0 -type d | sort); do  echo "$i | $(cd $i; ${GOPATH}/bin/logcheck -check-structured -check-deprecations=false 2>&1 ./... | wc -l ) | $(cd $i; ${GOPATH}/bin/logcheck -check-structured -check-deprecations=false -check-contextual ./... 2>&1 | wc -l )"; done
+```
+
+Note that this also counts calls where it was decided to not convert them. The
+actual check with golangci-lint ignores those because of a `//nolint:logcheck`
+suppression comment.
+
+Component | Non-Structured Logging | Non-Contextual Logging 
+------ | ------- |  -------
+cmd/clicheck | 0 | 0
+cmd/cloud-controller-manager | 6 | 8
+cmd/dependencycheck | 0 | 0
+cmd/dependencyverifier | 0 | 0
+cmd/fieldnamedocscheck | 1 | 1
+cmd/gendocs | 0 | 0
+cmd/genkubedocs | 0 | 0
+cmd/genman | 0 | 0
+cmd/genswaggertypedocs | 2 | 2
+cmd/genutils | 0 | 0
+cmd/genyaml | 0 | 0
+cmd/gotemplate | 0 | 0
+cmd/importverifier | 0 | 0
+cmd/kubeadm | 264 | 463
+cmd/kube-apiserver | 6 | 7
+cmd/kube-controller-manager | 0 | 0
+cmd/kubectl | 0 | 0
+cmd/kubectl-convert | 0 | 0
+cmd/kubelet | 0 | 52
+cmd/kubemark | 1 | 1
+cmd/kube-proxy | 0 | 42
+cmd/kube-scheduler | 0 | 0
+cmd/preferredimports | 0 | 0
+cmd/prune-junit-xml | 0 | 0
+cmd/yamlfmt | 0 | 0
+pkg/api | 0 | 0
+pkg/apis | 0 | 0
+pkg/auth | 1 | 1
+pkg/capabilities | 0 | 0
+pkg/client | 0 | 0
+pkg/cloudprovider | 0 | 0
+pkg/cluster | 0 | 0
+pkg/controller | 0 | 3
+pkg/controlplane | 53 | 69
+pkg/credentialprovider | 48 | 77
+pkg/features | 0 | 0
+pkg/fieldpath | 0 | 0
+pkg/generated | 0 | 0
+pkg/kubeapiserver | 4 | 4
+pkg/kubectl | 1 | 2
+pkg/kubelet | 2 | 1983
+pkg/kubemark | 7 | 7
+pkg/printers | 0 | 0
+pkg/probe | 7 | 24
+pkg/proxy | 0 | 360
+pkg/quota | 0 | 0
+pkg/registry | 46 | 99
+pkg/routes | 2 | 2
+pkg/scheduler | 0 | 0
+pkg/security | 0 | 0
+pkg/securitycontext | 0 | 0
+pkg/serviceaccount | 25 | 44
+pkg/util | 20 | 57
+pkg/volume | 704 | 1110
+pkg/windows | 1 | 1
+staging/src/k8s.io/api | 0 | 0
+staging/src/k8s.io/apiextensions-apiserver | 58 | 89
+staging/src/k8s.io/apimachinery | 80 | 125
+staging/src/k8s.io/apiserver | 285 | 655
+staging/src/k8s.io/client-go | 163 | 283
+staging/src/k8s.io/cli-runtime | 1 | 2
+staging/src/k8s.io/cloud-provider | 122 | 162
+staging/src/k8s.io/cluster-bootstrap | 2 | 4
+staging/src/k8s.io/code-generator | 108 | 155
+staging/src/k8s.io/component-base | 33 | 64
+staging/src/k8s.io/component-helpers | 2 | 4
+staging/src/k8s.io/controller-manager | 10 | 10
+staging/src/k8s.io/cri-api | 0 | 0
+staging/src/k8s.io/csi-translation-lib | 3 | 4
+staging/src/k8s.io/dynamic-resource-allocation | 0 | 0
+staging/src/k8s.io/endpointslice | 0 | 0
+staging/src/k8s.io/kms | 0 | 0
+staging/src/k8s.io/kube-aggregator | 45 | 62
+staging/src/k8s.io/kube-controller-manager | 0 | 0
+staging/src/k8s.io/kubectl | 96 | 160
+staging/src/k8s.io/kubelet | 0 | 32
+staging/src/k8s.io/kube-proxy | 0 | 0
+staging/src/k8s.io/kube-scheduler | 0 | 0
+staging/src/k8s.io/legacy-cloud-providers | 1281 | 2015
+staging/src/k8s.io/metrics | 0 | 0
+staging/src/k8s.io/mount-utils | 55 | 95
+staging/src/k8s.io/pod-security-admission | 0 | 1
+staging/src/k8s.io/sample-apiserver | 0 | 0
+staging/src/k8s.io/sample-cli-plugin | 0 | 0
+staging/src/k8s.io/sample-controller | 0 | 0
+
+For Kubernetes 1.30, the focus is on client-go. APIs need to be extended
+carefully without breaking existing code so that a context can be provided for
+log calls. In some cases, this also makes a context available to code which
+currently uses `context.TODO` as a stop-gap measure. Currently there are over
+300 of those in `staging/src/k8s.io/client-go`. Whenever new APIs get
+introduced, components which were already converted to contextual logging get
+updated to use those.
 
 ## Drawbacks