Description
When calling WithValues on a zap-backed logger, the value bypasses the KubeAwareEncoder, meaning it will be fully marshalled using the underlying encoder (e.g. json encoder).
For example:
If I add a key and value to the example controller here:
// Print the ReplicaSet
log.Info("Reconciling ReplicaSet", "replicaSet", rs, "container name", rs.Spec.Template.Spec.Containers[0].Name)it will use the KubeAwareEncoder (which is the desired behaviour)
{"level":"info", [...] "replicaSet":{"apiVersion":"apps/v1","kind":"ReplicaSet","namespace":"kube-system","name":"coredns-66bff467f8"},"container name":"coredns"}
But if I use WithValues, which helps avoiding to add the values for every log statement in a controller, like this:
// Print the ReplicaSet
log = log.WithValues("replicaSet", rs)
log.Info("Reconciling ReplicaSet", "container name", rs.Spec.Template.Spec.Containers[0].Name)it will bypass the KubeAwareEncoder and fully marshal the object into json, which will make the logs very hard to search:
{"level":"info", [...] "replicaSet":"&ReplicaSet{ObjectMeta:{coredns-66bff467f8 kube-system /apis/apps/v1/namespaces/kube-system/replicasets/coredns-66bff467f8 627fa1f9-ff8f-40fc-9f16-5df4dd71d567 13218 1 2020-12-04 13:49:52 +0100 CET <nil> <nil> map[hello:world k8s-app:kube-dns pod-template-hash:66bff467f8] map[deployment.kubernetes.io/desired-replicas:2 deployment.kubernetes.io/max-replicas:3 deployment.kubernetes.io/revision:1] [{apps/v1 Deployment coredns 9675a95d-33c0-42bc-82ae-b785d55280b1 0xc0004de338 0xc0004de339}] [] [{kube-controller-manager Update apps/v1 2020-12-04 13:50:21 +0100 CET FieldsV1 {\"f:metadata\":{\"f:annotations\":{\".\":{},\"f:deployment.kubernetes.io/desired-replicas\":{},\"f:deployment.kubernetes.io/max-replicas\":{},\"f:deployment.kubernetes.io/revision\":{}},\"f:labels\":{\".\":{},\"f:k8s-app\":{},\"f:pod-template-hash\":{}},\"f:ownerReferences\":{\".\":{},\"k:{\\\"uid\\\":\\\"9675a95d-33c0-42bc-82ae-b785d55280b1\\\"}\":{\".\":{},\"f:apiVersion\":{},\"f:blockOwnerDeletion\":{},\"f:controller\":{},\"f:kind\":{},\"f:name\":{},\"f:uid\":{}}}},\"f:spec\":{\"f:replicas\":{},\"f:selector\":{\"f:matchLabels\":{\".\":{},\"f:k8s-app\":{},\"f:pod-template-hash\":{}}},\"f:template\":{\"f:metadata\":{\"f:labels\":{\".\":{},\"f:k8s-app\":{},\"f:pod-template-hash\":{}}},\"f:spec\":{\"f:containers\":{\"k:{\\\"name\\\":\\\"coredns\\\"}\":{\".\":{},\"f:args\":{},\"f:image\":{},\"f:imagePullPolicy\":{},\"f:livenessProbe\":{\".\":{},\"f:failureThreshold\":{},\"f:httpGet\":{\".\":{},\"f:path\":{},\"f:port\":{},\"f:scheme\":{}},\"f:initialDelaySeconds\":{},\"f:periodSeconds\":{},\"f:successThreshold\":{},\"f:timeoutSeconds\":{}},\"f:name\":{},\"f:ports\":{\".\":{},\"k:{\\\"containerPort\\\":53,\\\"protocol\\\":\\\"TCP\\\"}\":{\".\":{},\"f:containerPort\":{},\"f:name\":{},\"f:protocol\":{}},\"k:{\\\"containerPort\\\":53,\\\"protocol\\\":\\\"UDP\\\"}\":{\".\":{},\"f:containerPort\":{},\"f:name\":{},\"f:protocol\":{}},\"k:{\\\"containerPort\\\":9153,\\\"protocol\\\":\\\"TCP\\\"}\":{\".\":{},\"f:containerPort\":{},\"f:name\":{},\"f:protocol\":{}}},\"f:readinessProbe\":{\".\":{},\"f:failureThreshold\":{},\"f:httpGet\":{\".\":{},\"f:path\":{},\"f:port\":{},\"f:scheme\":{}},\"f:periodSeconds\":{},\"f:successThreshold\":{},\"f:timeoutSeconds\":{}},\"f:resources\":{\".\":{},\"f:limits\":{\".\":{},\"f:memory\":{}},\"f:requests\":{\".\":{},\"f:cpu\":{},\"f:memory\":{}}},\"f:securityContext\":{\".\":{},\"f:allowPrivilegeEscalation\":{},\"f:capabilities\":{\".\":{},\"f:add\":{},\"f:drop\":{}},\"f:readOnlyRootFilesystem\":{}},\"f:terminationMessagePath\":{},\"f:terminationMessagePolicy\":{},\"f:volumeMounts\":{\".\":{},\"k:{\\\"mountPath\\\":\\\"/etc/coredns\\\"}\":{\".\":{},\"f:mountPath\":{},\"f:name\":{},\"f:readOnly\":{}}}}},\"f:dnsPolicy\":{},\"f:nodeSelector\":{\".\":{},\"f:kubernetes.io/os\":{}},\"f:priorityClassName\":{},\"f:restartPolicy\":{},\"f:schedulerName\":{},\"f:securityContext\":{},\"f:serviceAccount\":{},\"f:serviceAccountName\":{},\"f:terminationGracePeriodSeconds\":{},\"f:tolerations\":{},\"f:volumes\":{\".\":{},\"k:{\\\"name\\\":\\\"config-volume\\\"}\":{\".\":{},\"f:configMap\":{\".\":{},\"f:defaultMode\":{},\"f:items\":{},\"f:name\":{}},\"f:name\":{}}}}}},\"f:status\":{\"f:availableReplicas\":{},\"f:fullyLabeledReplicas\":{},\"f:observedGeneration\":{},\"f:readyReplicas\":{},\"f:replicas\":{}}}} {builtins Update apps/v1 2020-12-04 15:08:51 +0100 CET FieldsV1 {\"f:metadata\":{\"f:labels\":{\"f:hello\":{}}}}}]},Spec:ReplicaSetSpec{Replicas:*2,Selector:&v1.LabelSelector{MatchLabels:map[string]string{k8s-app: kube-dns,pod-template-hash: 66bff467f8,},MatchExpressions:[]LabelSelectorRequirement{},},Template:{{ 0 0001-01-01 00:00:00 +0000 UTC <nil> <nil> map[k8s-app:kube-dns pod-template-hash:66bff467f8] map[] [] [] []} {[{config-volume {nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil ConfigMapVolumeSource{LocalObjectReference:LocalObjectReference{Name:coredns,},Items:[]KeyToPath{KeyToPath{Key:Corefile,Path:Corefile,Mode:nil,},},DefaultMode:*420,Optional:nil,} nil nil nil nil nil nil nil nil nil nil}}] [] [{coredns k8s.gcr.io/coredns:1.6.7 [] [-conf /etc/coredns/Corefile] [{dns 0 53 UDP } {dns-tcp 0 53 TCP } {metrics 0 9153 TCP }] [] [] {map[memory:{{178257920 0} {<nil>} 170Mi BinarySI}] map[cpu:{{100 -3} {<nil>} 100m DecimalSI} memory:{{73400320 0} {<nil>} 70Mi BinarySI}]} [{config-volume true /etc/coredns <nil> }] [] &Probe{Handler:Handler{Exec:nil,HTTPGet:&HTTPGetAction{Path:/health,Port:{0 8080 },Host:,Scheme:HTTP,HTTPHeaders:[]HTTPHeader{},},TCPSocket:nil,},InitialDelaySeconds:60,TimeoutSeconds:5,PeriodSeconds:10,SuccessThreshold:1,FailureThreshold:5,} &Probe{Handler:Handler{Exec:nil,HTTPGet:&HTTPGetAction{Path:/ready,Port:{0 8181 },Host:,Scheme:HTTP,HTTPHeaders:[]HTTPHeader{},},TCPSocket:nil,},InitialDelaySeconds:0,TimeoutSeconds:1,PeriodSeconds:10,SuccessThreshold:1,FailureThreshold:3,} nil nil /dev/termination-log File IfNotPresent &SecurityContext{Capabilities:&Capabilities{Add:[NET_BIND_SERVICE],Drop:[all],},Privileged:nil,SELinuxOptions:nil,RunAsUser:nil,RunAsNonRoot:nil,ReadOnlyRootFilesystem:*true,AllowPrivilegeEscalation:*false,RunAsGroup:nil,ProcMount:nil,WindowsOptions:nil,SeccompProfile:nil,} false false false}] [] Always 0xc0004de398 <nil> Default map[kubernetes.io/os:linux] coredns coredns <nil> false false false <nil> &PodSecurityContext{SELinuxOptions:nil,RunAsUser:nil,RunAsNonRoot:nil,SupplementalGroups:[],FSGroup:nil,RunAsGroup:nil,Sysctls:[]Sysctl{},WindowsOptions:nil,FSGroupChangePolicy:nil,SeccompProfile:nil,} [] nil default-scheduler [{CriticalAddonsOnly Exists <nil>} {node-role.kubernetes.io/master NoSchedule <nil>}] [] system-cluster-critical <nil> nil [] <nil> <nil> <nil> map[] [] <nil>}},MinReadySeconds:0,},Status:ReplicaSetStatus{Replicas:2,FullyLabeledReplicas:2,ObservedGeneration:1,ReadyReplicas:2,AvailableReplicas:2,Conditions:[]ReplicaSetCondition{},},}","container name":"coredns"}
I didn't find any issue/discussion related to a fix for this, other than this note from @DirectXMan12:
So I'm opening this issue to see what can be done here to fix this behaviour.