kubelet 在 Microk8s 中没有配置 ClusterDNS IP
kubelet does not have ClusterDNS IP configured in Microk8s
我在 ubuntu
中使用 microk8s
我正在尝试 运行 一个简单的 hello world 程序，但在创建 pod 时出现错误。
kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy
这是我正在尝试应用的 deployment.yaml 文件。
apiVersion: v1
kind: Service
metadata:
name: grpc-hello
spec:
ports:
- port: 80
targetPort: 9000
protocol: TCP
name: http
selector:
app: grpc-hello
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: grpc-hello
spec:
replicas: 1
selector:
matchLabels:
app: grpc-hello
template:
metadata:
labels:
app: grpc-hello
spec:
containers:
- name: esp
image: gcr.io/endpoints-release/endpoints-runtime:1
args: [
"--http2_port=9000",
"--backend=grpc://127.0.0.1:50051",
"--service=hellogrpc.endpoints.octa-test-123.cloud.goog",
"--rollout_strategy=managed",
]
ports:
- containerPort: 9000
- name: python-grpc-hello
image: gcr.io/octa-test-123/python-grpc-hello:1.0
ports:
- containerPort: 50051
这是我尝试 describe pod
时得到的结果
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 31s default-scheduler Successfully assigned default/grpc-hello-66869cf9fb-kpr69 to azeem-ubuntu
Normal Started 30s kubelet, azeem-ubuntu Started container python-grpc-hello
Normal Pulled 30s kubelet, azeem-ubuntu Container image "gcr.io/octa-test-123/python-grpc-hello:1.0" already present on machine
Normal Created 30s kubelet, azeem-ubuntu Created container python-grpc-hello
Normal Pulled 12s (x3 over 31s) kubelet, azeem-ubuntu Container image "gcr.io/endpoints-release/endpoints-runtime:1" already present on machine
Normal Created 12s (x3 over 31s) kubelet, azeem-ubuntu Created container esp
Normal Started 12s (x3 over 30s) kubelet, azeem-ubuntu Started container esp
Warning MissingClusterDNS 8s (x10 over 31s) kubelet, azeem-ubuntu pod: "grpc-hello-66869cf9fb-kpr69_default(19c5a870-fcf5-415c-bcb6-dedfc11f936c)". kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
Warning BackOff 8s (x2 over 23s) kubelet, azeem-ubuntu Back-off restarting failed container
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 31s default-scheduler Successfully assigned default/grpc-hello-66869cf9fb-kpr69 to azeem-ubuntu
Normal Started 30s kubelet, azeem-ubuntu Started container python-grpc-hello
Normal Pulled 30s kubelet, azeem-ubuntu Container image "gcr.io/octa-test-123/python-grpc-hello:1.0" already present on machine
Normal Created 30s kubelet, azeem-ubuntu Created container python-grpc-hello
Normal Pulled 12s (x3 over 31s) kubelet, azeem-ubuntu Container image "gcr.io/endpoints-release/endpoints-runtime:1" already present on machine
Normal Created 12s (x3 over 31s) kubelet, azeem-ubuntu Created container esp
Normal Started 12s (x3 over 30s) kubelet, azeem-ubuntu Started container esp
Warning MissingClusterDNS 8s (x10 over 31s) kubelet, azeem-ubuntu pod: "grpc-hello-66869cf9fb-kpr69_default(19c5a870-fcf5-415c-bcb6-dedfc11f936c)". kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
Warning BackOff 8s (x2 over 23s) kubelet, azeem-ubuntu Back-off restarting failed container
我对此进行了很多搜索，我找到了一些答案，但没有人为我工作我也为此创建了 kube-dns，但不知道为什么它仍然不起作用。这些 kube-dns 是 运行ning。 kube-dns 在 kube-system 命名空间中。
NAME READY STATUS RESTARTS AGE
kube-dns-6dbd676f7-dfbjq 3/3 Running 0 22m
这是我申请创建 kube-dns
apiVersion: v1
kind: Service
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "KubeDNS"
spec:
selector:
k8s-app: kube-dns
clusterIP: 10.152.183.10
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: kube-dns
namespace: kube-system
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: v1
kind: ConfigMap
metadata:
name: kube-dns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: EnsureExists
data:
upstreamNameservers: |-
["8.8.8.8", "8.8.4.4"]
# Why set upstream ns: https://github.com/kubernetes/minikube/issues/2027
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
# replicas: not specified here:
# 1. In order to make Addon Manager do not reconcile this replicas parameter.
# 2. Default is 1.
# 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
strategy:
rollingUpdate:
maxSurge: 10%
maxUnavailable: 0
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
volumes:
- name: kube-dns-config
configMap:
name: kube-dns
optional: true
containers:
- name: kubedns
image: gcr.io/google-containers/k8s-dns-kube-dns:1.15.8
resources:
# TODO: Set memory limits when we've profiled the container for large
# clusters, then set request = limit to keep this container in
# guaranteed class. Currently, this container falls into the
# "burstable" category so the kubelet doesn't backoff from restarting it.
limits:
memory: 170Mi
requests:
cpu: 100m
memory: 70Mi
livenessProbe:
httpGet:
path: /healthcheck/kubedns
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
# we poll on pod startup for the Kubernetes master service and
# only setup the /readiness HTTP server once that's available.
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=cluster.local.
- --dns-port=10053
- --config-dir=/kube-dns-config
- --v=2
env:
- name: PROMETHEUS_PORT
value: "10055"
ports:
- containerPort: 10053
name: dns-local
protocol: UDP
- containerPort: 10053
name: dns-tcp-local
protocol: TCP
- containerPort: 10055
name: metrics
protocol: TCP
volumeMounts:
- name: kube-dns-config
mountPath: /kube-dns-config
- name: dnsmasq
image: gcr.io/google-containers/k8s-dns-dnsmasq-nanny:1.15.8
livenessProbe:
httpGet:
path: /healthcheck/dnsmasq
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- -v=2
- -logtostderr
- -configDir=/etc/k8s/dns/dnsmasq-nanny
- -restartDnsmasq=true
- --
- -k
- --cache-size=1000
- --no-negcache
- --log-facility=-
- --server=/cluster.local/127.0.0.1#10053
- --server=/in-addr.arpa/127.0.0.1#10053
- --server=/ip6.arpa/127.0.0.1#10053
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
# see: https://github.com/kubernetes/kubernetes/issues/29055 for details
resources:
requests:
cpu: 150m
memory: 20Mi
volumeMounts:
- name: kube-dns-config
mountPath: /etc/k8s/dns/dnsmasq-nanny
- name: sidecar
image: gcr.io/google-containers/k8s-dns-sidecar:1.15.8
livenessProbe:
httpGet:
path: /metrics
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- --v=2
- --logtostderr
- --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local,5,SRV
- --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local,5,SRV
ports:
- containerPort: 10054
name: metrics
protocol: TCP
resources:
requests:
memory: 20Mi
cpu: 10m
dnsPolicy: Default # Don't use cluster DNS.
serviceAccountName: kube-dns
请让我知道我缺少什么。
您尚未指定如何部署 kube dns，但对于 microk8s，建议使用核心 dns。您不应该自己部署 kube dns 或核心 dns，而是需要使用此命令启用 dns microk8s enable dns，这将部署核心 DNS 并设置 DNS。
我在 microk8s 集群上遇到了同样的问题。尽管我已经启用了 dns add-on，但它不起作用。
我用
查找服务 kube-dns 的 cluster-ip 地址
kubectl -nkube-system get svc/kube-dns
我停止了 microk8s 集群并编辑了 kubelet 配置文件 /var/snap/microk8s/current/args/kubelet 并在我的案例中添加了以下行：
--resolv-conf=""
--cluster-dns=A.B.C.D
--cluster-domain=cluster.local
后来启动集群，问题没有再出现
我在 ubuntu
microk8s
我正在尝试 运行 一个简单的 hello world 程序，但在创建 pod 时出现错误。
kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy
这是我正在尝试应用的 deployment.yaml 文件。
apiVersion: v1
kind: Service
metadata:
name: grpc-hello
spec:
ports:
- port: 80
targetPort: 9000
protocol: TCP
name: http
selector:
app: grpc-hello
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: grpc-hello
spec:
replicas: 1
selector:
matchLabels:
app: grpc-hello
template:
metadata:
labels:
app: grpc-hello
spec:
containers:
- name: esp
image: gcr.io/endpoints-release/endpoints-runtime:1
args: [
"--http2_port=9000",
"--backend=grpc://127.0.0.1:50051",
"--service=hellogrpc.endpoints.octa-test-123.cloud.goog",
"--rollout_strategy=managed",
]
ports:
- containerPort: 9000
- name: python-grpc-hello
image: gcr.io/octa-test-123/python-grpc-hello:1.0
ports:
- containerPort: 50051
这是我尝试 describe pod
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 31s default-scheduler Successfully assigned default/grpc-hello-66869cf9fb-kpr69 to azeem-ubuntu
Normal Started 30s kubelet, azeem-ubuntu Started container python-grpc-hello
Normal Pulled 30s kubelet, azeem-ubuntu Container image "gcr.io/octa-test-123/python-grpc-hello:1.0" already present on machine
Normal Created 30s kubelet, azeem-ubuntu Created container python-grpc-hello
Normal Pulled 12s (x3 over 31s) kubelet, azeem-ubuntu Container image "gcr.io/endpoints-release/endpoints-runtime:1" already present on machine
Normal Created 12s (x3 over 31s) kubelet, azeem-ubuntu Created container esp
Normal Started 12s (x3 over 30s) kubelet, azeem-ubuntu Started container esp
Warning MissingClusterDNS 8s (x10 over 31s) kubelet, azeem-ubuntu pod: "grpc-hello-66869cf9fb-kpr69_default(19c5a870-fcf5-415c-bcb6-dedfc11f936c)". kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
Warning BackOff 8s (x2 over 23s) kubelet, azeem-ubuntu Back-off restarting failed container
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 31s default-scheduler Successfully assigned default/grpc-hello-66869cf9fb-kpr69 to azeem-ubuntu
Normal Started 30s kubelet, azeem-ubuntu Started container python-grpc-hello
Normal Pulled 30s kubelet, azeem-ubuntu Container image "gcr.io/octa-test-123/python-grpc-hello:1.0" already present on machine
Normal Created 30s kubelet, azeem-ubuntu Created container python-grpc-hello
Normal Pulled 12s (x3 over 31s) kubelet, azeem-ubuntu Container image "gcr.io/endpoints-release/endpoints-runtime:1" already present on machine
Normal Created 12s (x3 over 31s) kubelet, azeem-ubuntu Created container esp
Normal Started 12s (x3 over 30s) kubelet, azeem-ubuntu Started container esp
Warning MissingClusterDNS 8s (x10 over 31s) kubelet, azeem-ubuntu pod: "grpc-hello-66869cf9fb-kpr69_default(19c5a870-fcf5-415c-bcb6-dedfc11f936c)". kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
Warning BackOff 8s (x2 over 23s) kubelet, azeem-ubuntu Back-off restarting failed container
我对此进行了很多搜索，我找到了一些答案，但没有人为我工作我也为此创建了 kube-dns，但不知道为什么它仍然不起作用。这些 kube-dns 是 运行ning。 kube-dns 在 kube-system 命名空间中。
NAME READY STATUS RESTARTS AGE
kube-dns-6dbd676f7-dfbjq 3/3 Running 0 22m
这是我申请创建 kube-dns
apiVersion: v1
kind: Service
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
kubernetes.io/name: "KubeDNS"
spec:
selector:
k8s-app: kube-dns
clusterIP: 10.152.183.10
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: kube-dns
namespace: kube-system
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: v1
kind: ConfigMap
metadata:
name: kube-dns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: EnsureExists
data:
upstreamNameservers: |-
["8.8.8.8", "8.8.4.4"]
# Why set upstream ns: https://github.com/kubernetes/minikube/issues/2027
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: kube-dns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
# replicas: not specified here:
# 1. In order to make Addon Manager do not reconcile this replicas parameter.
# 2. Default is 1.
# 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
strategy:
rollingUpdate:
maxSurge: 10%
maxUnavailable: 0
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
volumes:
- name: kube-dns-config
configMap:
name: kube-dns
optional: true
containers:
- name: kubedns
image: gcr.io/google-containers/k8s-dns-kube-dns:1.15.8
resources:
# TODO: Set memory limits when we've profiled the container for large
# clusters, then set request = limit to keep this container in
# guaranteed class. Currently, this container falls into the
# "burstable" category so the kubelet doesn't backoff from restarting it.
limits:
memory: 170Mi
requests:
cpu: 100m
memory: 70Mi
livenessProbe:
httpGet:
path: /healthcheck/kubedns
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /readiness
port: 8081
scheme: HTTP
# we poll on pod startup for the Kubernetes master service and
# only setup the /readiness HTTP server once that's available.
initialDelaySeconds: 3
timeoutSeconds: 5
args:
- --domain=cluster.local.
- --dns-port=10053
- --config-dir=/kube-dns-config
- --v=2
env:
- name: PROMETHEUS_PORT
value: "10055"
ports:
- containerPort: 10053
name: dns-local
protocol: UDP
- containerPort: 10053
name: dns-tcp-local
protocol: TCP
- containerPort: 10055
name: metrics
protocol: TCP
volumeMounts:
- name: kube-dns-config
mountPath: /kube-dns-config
- name: dnsmasq
image: gcr.io/google-containers/k8s-dns-dnsmasq-nanny:1.15.8
livenessProbe:
httpGet:
path: /healthcheck/dnsmasq
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- -v=2
- -logtostderr
- -configDir=/etc/k8s/dns/dnsmasq-nanny
- -restartDnsmasq=true
- --
- -k
- --cache-size=1000
- --no-negcache
- --log-facility=-
- --server=/cluster.local/127.0.0.1#10053
- --server=/in-addr.arpa/127.0.0.1#10053
- --server=/ip6.arpa/127.0.0.1#10053
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
# see: https://github.com/kubernetes/kubernetes/issues/29055 for details
resources:
requests:
cpu: 150m
memory: 20Mi
volumeMounts:
- name: kube-dns-config
mountPath: /etc/k8s/dns/dnsmasq-nanny
- name: sidecar
image: gcr.io/google-containers/k8s-dns-sidecar:1.15.8
livenessProbe:
httpGet:
path: /metrics
port: 10054
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
args:
- --v=2
- --logtostderr
- --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local,5,SRV
- --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local,5,SRV
ports:
- containerPort: 10054
name: metrics
protocol: TCP
resources:
requests:
memory: 20Mi
cpu: 10m
dnsPolicy: Default # Don't use cluster DNS.
serviceAccountName: kube-dns
请让我知道我缺少什么。
您尚未指定如何部署 kube dns，但对于 microk8s，建议使用核心 dns。您不应该自己部署 kube dns 或核心 dns，而是需要使用此命令启用 dns microk8s enable dns，这将部署核心 DNS 并设置 DNS。
我在 microk8s 集群上遇到了同样的问题。尽管我已经启用了 dns add-on，但它不起作用。 我用
查找服务 kube-dns 的 cluster-ip 地址kubectl -nkube-system get svc/kube-dns
我停止了 microk8s 集群并编辑了 kubelet 配置文件 /var/snap/microk8s/current/args/kubelet 并在我的案例中添加了以下行：
--resolv-conf=""
--cluster-dns=A.B.C.D
--cluster-domain=cluster.local
后来启动集群，问题没有再出现