Is this a BUG REPORT or FEATURE REQUEST?:
/kind bug
What happened:
I attempted to create a cluster using the kubeadm
tool with ABAC authorisation enabled using the below configuration files.
~/config.yaml
apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
networking:
podSubnet: 10.244.0.0/16
authorizationModes:
- Node
- RBAC
- ABAC
apiServerExtraArgs:
basic-auth-file: /etc/kubernetes/basic_auth.csv
authorization-policy-file: /etc/kubernetes/abac_policy.json
~/basic_auth.csv
admin,admin,1,"system:masters"
~/abac_policy.json
{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"user":"*", "nonResourcePath": "*", "readonly": true}}
{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"user":"admin", "namespace": "*", "resource": "*", "apiGroup": "*"}}
{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"group":"system:serviceaccounts", "namespace": "*", "resource": "*", "apiGroup": "*", "nonResourcePath": "*"}}
The kubeadm
command hangs with the following output...
[init] Using Kubernetes version: v1.9.3
[init] Using Authorization modes: [Node RBAC ABAC]
[preflight] Running pre-flight checks.
[WARNING FileExisting-crictl]: crictl not found in system path
[preflight] Starting the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [####### #######]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests".
[init] This might take a minute or longer if the control plane images have to be pulled.
It looks like the kube-apiserver
container is constantly restarted.
The log output from the kube-apiserver
container gives
I0306 12:39:33.179719 1 server.go:121] Version: v1.9.3
invalid authentication config: open /etc/kubernetes/basic_auth.csv: no such file or directory
What you expected to happen:
I expected the kube-apiserver
to start.
How to reproduce it (as minimally and precisely as possible):
mkdir -p /etc/kubernetes
cp ~/basic_auth.csv /etc/kubernetes
cp ~/abac_policy.json /etc/kubernetes
kubeadm init --config ~/config.yaml
Anything else we need to know?:
Environment:
kubectl version
): v1.9.3uname -a
): Linux k8s-master 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64 x86_64 x86_64 GNU/LinuxIt seems that maybe the /etc/kubernetes/basic_auth.csv
and /etc/kubernetes/abac_policy.json
files are not mounted inside the kube-apiserver
container.
I tried using the following extra volumes stanza but I couldn't get it to work with files, it only seems to work with directories.
apiServerExtraVolumes:
- name: <value|string>
hostPath: <value|string>
mountPath: <value|string>
If I try mounting a directory containing the two files and specify the new locations in the config it still looks for them in the default location! See the generated /etc/kubernetes/manifests/kube-apiserver.yaml
below, it has two entries for the --authorization-policy-file
option, the second seemingly overrides the first.
apiVersion: v1
kind: Pod
metadata:
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ""
creationTimestamp: null
labels:
component: kube-apiserver
tier: control-plane
name: kube-apiserver
namespace: kube-system
spec:
containers:
- command:
- kube-apiserver
- --authorization-policy-file=/etc/kubernetes/users/abac_policy.json
- --basic-auth-file=/etc/kubernetes/users/basic_auth.csv
- --service-account-key-file=/etc/kubernetes/pki/sa.pub
- --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
- --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key
- --admission-control=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,ResourceQuota
- --enable-bootstrap-token-auth=true
- --allow-privileged=true
- --requestheader-group-headers=X-Remote-Group
- --advertise-address=#######
- --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
- --insecure-port=0
- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
- --requestheader-extra-headers-prefix=X-Remote-Extra-
- --tls-cert-file=/etc/kubernetes/pki/apiserver.crt
- --secure-port=6443
- --requestheader-username-headers=X-Remote-User
- --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt
- --requestheader-allowed-names=front-proxy-client
- --service-cluster-ip-range=10.96.0.0/12
- --client-ca-file=/etc/kubernetes/pki/ca.crt
- --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
- --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
- --authorization-policy-file=/etc/kubernetes/abac_policy.json
- --authorization-mode=Node,RBAC,ABAC
- --etcd-servers=http://127.0.0.1:2379
image: gcr.io/google_containers/kube-apiserver-amd64:v1.9.3
livenessProbe:
failureThreshold: 8
httpGet:
host: #######
path: /healthz
port: 6443
scheme: HTTPS
initialDelaySeconds: 15
timeoutSeconds: 15
name: kube-apiserver
resources:
requests:
cpu: 250m
volumeMounts:
- mountPath: /etc/kubernetes/pki
name: k8s-certs
readOnly: true
- mountPath: /etc/ssl/certs
name: ca-certs
readOnly: true
- mountPath: /etc/kubernetes/users
name: users
readOnly: true
hostNetwork: true
volumes:
- hostPath:
path: /etc/kubernetes/pki
type: DirectoryOrCreate
name: k8s-certs
- hostPath:
path: /etc/ssl/certs
type: DirectoryOrCreate
name: ca-certs
- hostPath:
path: /etc/kubernetes/users
type: DirectoryOrCreate
name: users
status: {}
@msnelling - We generally discourage ABAC enablement, but it does look like an over-ride issue.
Where possible please open issues against the https://github.com/kubernetes/kubeadm repo.
Most helpful comment
It seems that maybe the
/etc/kubernetes/basic_auth.csv
and/etc/kubernetes/abac_policy.json
files are not mounted inside thekube-apiserver
container.I tried using the following extra volumes stanza but I couldn't get it to work with files, it only seems to work with directories.
If I try mounting a directory containing the two files and specify the new locations in the config it still looks for them in the default location! See the generated
/etc/kubernetes/manifests/kube-apiserver.yaml
below, it has two entries for the--authorization-policy-file
option, the second seemingly overrides the first.