kube-controller-manager is not logging details - kubernetes

Question

I have an issue setting up persistant volumes for gitlab on my bare-metal kubernetes cluster:
Operation for "provision-gitlab/repo-data-gitlab-gitaly-0[3f758288-290c-4d9c-a084-5506f58a22d7]" failed. No retries permitted until 2020-11-28 11:55:56.533202624 +0000 UTC m=+305.008238514 (durationBeforeRetry 4s). Error: "failed to create volume: failed to create volume: see kube-controller-manager.log for details"
Problem is: this file doesn't exist anywhere, and I cannot get any more details about the problem, even by adapting the configuration:
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
component: kube-controller-manager
tier: control-plane
name: kube-controller-manager
namespace: kube-system
spec:
containers:
- command:
- kube-controller-manager
- --allocate-node-cidrs=true
- --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf
- --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf
- --bind-address=127.0.0.1
- --client-ca-file=/etc/kubernetes/pki/ca.crt
- --cluster-cidr=192.168.0.0/16
- --cluster-name=kubernetes
- --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt
- --cluster-signing-key-file=/etc/kubernetes/pki/ca.key
- --controllers=*,bootstrapsigner,tokencleaner
- --kubeconfig=/etc/kubernetes/controller-manager.conf
- --leader-elect=true
- --node-cidr-mask-size=24
- --port=0
- --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
- --root-ca-file=/etc/kubernetes/pki/ca.crt
- --service-account-private-key-file=/etc/kubernetes/pki/sa.key
- --service-cluster-ip-range=10.96.0.0/12
- --use-service-account-credentials=true
- --log-dir=/var/log/
- --log-file=kube-controller-manager.log
- --logtostderr=false
image: k8s.gcr.io/kube-controller-manager:v1.19.4
imagePullPolicy: IfNotPresent
livenessProbe:
failureThreshold: 8
httpGet:
host: 127.0.0.1
path: /healthz
port: 10257
scheme: HTTPS
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 15
name: kube-controller-manager
resources:
requests:
cpu: 200m
startupProbe:
failureThreshold: 24
httpGet:
host: 127.0.0.1
path: /healthz
port: 10257
scheme: HTTPS
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 15
volumeMounts:
- mountPath: /var/log/kube-controller-manager.log
name: logfile
- mountPath: /etc/ssl/certs
name: ca-certs
readOnly: true
- mountPath: /etc/ca-certificates
name: etc-ca-certificates
readOnly: true
- mountPath: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
name: flexvolume-dir
- mountPath: /etc/kubernetes/pki
name: k8s-certs
readOnly: true
- mountPath: /etc/kubernetes/controller-manager.conf
name: kubeconfig
readOnly: true
- mountPath: /usr/local/share/ca-certificates
name: usr-local-share-ca-certificates
readOnly: true
- mountPath: /usr/share/ca-certificates
name: usr-share-ca-certificates
readOnly: true
hostNetwork: true
priorityClassName: system-node-critical
volumes:
- hostPath:
path: /var/log/kube-controller-manager.log
name: logfile
- hostPath:
path: /etc/ssl/certs
type: DirectoryOrCreate
name: ca-certs
- hostPath:
path: /etc/ca-certificates
type: DirectoryOrCreate
name: etc-ca-certificates
- hostPath:
path: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
type: DirectoryOrCreate
name: flexvolume-dir
- hostPath:
path: /etc/kubernetes/pki
type: DirectoryOrCreate
name: k8s-certs
- hostPath:
path: /etc/kubernetes/controller-manager.conf
type: FileOrCreate
name: kubeconfig
- hostPath:
path: /usr/local/share/ca-certificates
type: DirectoryOrCreate
name: usr-local-share-ca-certificates
- hostPath:
path: /usr/share/ca-certificates
type: DirectoryOrCreate
name: usr-share-ca-certificates
status: {}
I tried to create it by hand, change permissions on it, but the pod is still not logging in this file

Answer 1

Control Plane components use klog library for logging which, for the moment, is rather badly documented.
Actually --log-dir and --log-file are mutually exclusive.
## it should be either --log-dir
--log-dir=/var/log/kube
...
volumeMounts:
- mountPath: /var/log/kube
name: log
...
volumes:
- hostPath:
path: /var/log/kube
type: DirectoryOrCreate
name: log
## or --log-file
--log-file=/var/log/kube-controller-manager.log
...
volumeMounts:
- mountPath: /var/log/kube-controller-manager.log
name: log
...
volumes:
- hostPath:
path: /var/log/kube-controller-manager.log
type: FileOrCreate
name: log
With --log-dir a component will write each log level a into separate file inside a given dir.
So you'll have a set of files with names like kube-controller-manager.INFO.log
With --log-file you'll have a single file as expected.
Don't forget to specify FileOrCreate in your volume definition, otherwise a directory will created by default.