刚开始使用 kubernetes。我有三台物理机器：1 台主机器，2 台节点。我基本上做了入门配置。一切似乎都在运行，节点可以与 master 通信，但是当我尝试安装示例应用程序时(请参阅以下 kubernetes 指南( 我一遍又一遍地收到这个警告：
kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
而且我无法访问该应用程序：master_ip：30001
知道发生了什么以及如何解决它吗？
配置
以下是配置：
$ kubectl get nodes
NAME STATUS AGE VERSION
master-precision-t1600 Ready 19h v1.7.4
node2-precision-t1600 Ready 19h v1.7.4
$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system etcd-master-precision-t1600 1/1 Running 1 19h
kube-system kube-apiserver-master-precision-t1600 1/1 Running 1 19h
kube-system kube-controller-manager-master-precision-t1600 1/1 Running 1 19h
kube-system kube-dns-2425271678-xrlp4 3/3 Running 3 19h
kube-system kube-proxy-58qm6 1/1 Running 1 19h
kube-system kube-proxy-tjskl 1/1 Running 1 19h
kube-system kube-scheduler-master-precision-t1600 1/1 Running 1 19h
kube-system kubernetes-dashboard-3313488171-7n56j 1/1 Running 0 38m
kube-system weave-net-1hjxl 2/2 Running 2 19h
kube-system weave-net-lwk8r 2/2 Running 2 19h
sock-shop carts-2469883122-h8f4n 1/1 Running 0 1h
sock-shop carts-db-1721187500-pkpk0 1/1 Running 0 1h
sock-shop catalogue-4293036822-hpkgp 1/1 Running 0 1h
sock-shop catalogue-db-1846494424-xlb8m 1/1 Running 0 1h
sock-shop front-end-2337481689-s8bkm 1/1 Running 0 1h
sock-shop orders-733484335-n7h4c 1/1 Running 0 1h
sock-shop orders-db-3728196820-12rt8 1/1 Running 0 1h
sock-shop payment-3050936124-kwqfs 1/1 Running 0 1h
sock-shop queue-master-2067646375-n8sgj 1/1 Running 0 1h
sock-shop rabbitmq-241640118-dqh6p 1/1 Running 0 1h
sock-shop shipping-2463450563-g01sw 1/1 Running 0 1h
sock-shop user-1574605338-kwqmp 1/1 Running 0 1h
sock-shop user-db-3152184577-w3f39 1/1 Running 0 1h
$ kubectl describe nodes
Name: master-precision-t1600
Role:
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=master-precision-t1600
node-role.kubernetes.io/master=
Annotations: node.alpha.kubernetes.io/ttl=0
volumes.kubernetes.io/controller-managed-attach-detach=true
Taints: node-role.kubernetes.io/master:NoSchedule
CreationTimestamp: Tue, 22 Aug 2017 17:05:06 +0200
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
OutOfDisk False Wed, 23 Aug 2017 12:26:45 +0200 Tue, 22 Aug 2017 17:05:02 +0200 KubeletHasSufficientDisk kubelet has sufficient disk space available
MemoryPressure False Wed, 23 Aug 2017 12:26:45 +0200 Tue, 22 Aug 2017 17:05:02 +0200 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Wed, 23 Aug 2017 12:26:45 +0200 Tue, 22 Aug 2017 17:05:02 +0200 KubeletHasNoDiskPressure kubelet has no disk pressure
Ready True Wed, 23 Aug 2017 12:26:45 +0200 Tue, 22 Aug 2017 17:05:02 +0200 KubeletReady kubelet is posting ready status. AppArmor enabled
Addresses:
InternalIP: xxx.xxx.xxx.215
Hostname: master-precision-t1600
Capacity:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 8
memory: 8127968Ki
pods: 110
Allocatable:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 8
memory: 8025568Ki
pods: 110
System Info:
Machine ID: d718aa59fbe54581a9b058eb453ca453
System UUID: 4C4C4544-005A-4410-805A-C4C04F32354A
Boot ID: 687c603a-aad9-477a-a398-dfffeeaa4cd0
Kernel Version: 4.10.0-32-generic
OS Image: Ubuntu 16.04.3 LTS
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://1.11.2
Kubelet Version: v1.7.4
Kube-Proxy Version: v1.7.4
ExternalID: master-precision-t1600
Non-terminated Pods: (8 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits
--------- ---- ------------ ---------- --------------- -------------
kube-system etcd-master-precision-t1600 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-apiserver-master-precision-t1600 250m (3%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-controller-manager-master-precision-t1600 200m (2%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-dns-2425271678-xrlp4 260m (3%) 0 (0%) 110Mi (1%) 170Mi (2%)
kube-system kube-proxy-58qm6 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system kube-scheduler-master-precision-t1600 100m (1%) 0 (0%) 0 (0%) 0 (0%)
kube-system kubernetes-dashboard-3313488171-7n56j 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system weave-net-1hjxl 20m (0%) 0 (0%) 0 (0%) 0 (0%)
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
CPU Requests CPU Limits Memory Requests Memory Limits
------------ ---------- --------------- -------------
830m (10%) 0 (0%) 110Mi (1%) 170Mi (2%)
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
39m 30s 36 kubelet, master-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "kubernetes-dashboard-3313488171-7n56j_kube-system(1ed597d4-87e8-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
Name: node2-precision-t1600
Role:
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=node2-precision-t1600
Annotations: node.alpha.kubernetes.io/ttl=0
volumes.kubernetes.io/controller-managed-attach-detach=true
Taints: <none>
CreationTimestamp: Tue, 22 Aug 2017 17:10:43 +0200
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
OutOfDisk False Wed, 23 Aug 2017 12:26:49 +0200 Wed, 23 Aug 2017 11:42:43 +0200 KubeletHasSufficientDisk kubelet has sufficient disk space available
MemoryPressure False Wed, 23 Aug 2017 12:26:49 +0200 Wed, 23 Aug 2017 11:42:43 +0200 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Wed, 23 Aug 2017 12:26:49 +0200 Wed, 23 Aug 2017 11:42:43 +0200 KubeletHasNoDiskPressure kubelet has no disk pressure
Ready True Wed, 23 Aug 2017 12:26:49 +0200 Wed, 23 Aug 2017 11:42:43 +0200 KubeletReady kubelet is posting ready status. AppArmor enabled
Addresses:
InternalIP: 129.241.110.167
Hostname: node2-precision-t1600
Capacity:
alpha.kubernetes.io/nvidia-gpu: 1
cpu: 8
memory: 8127968Ki
pods: 110
Allocatable:
alpha.kubernetes.io/nvidia-gpu: 1
cpu: 8
memory: 8025568Ki
pods: 110
System Info:
Machine ID: d701c70173f547168978ca276552bb88
System UUID: 4C4C4544-005A-4410-805A-B5C04F32354A
Boot ID: 827de455-66cb-481d-a362-557a17db11f4
Kernel Version: 4.10.0-32-generic
OS Image: Ubuntu 16.04.3 LTS
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://1.11.2
Kubelet Version: v1.7.4
Kube-Proxy Version: v1.7.4
ExternalID: node2-precision-t1600
Non-terminated Pods: (15 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits
--------- ---- ------------ ---------- --------------- -------------
kube-system kube-proxy-tjskl 0 (0%) 0 (0%) 0 (0%) 0 (0%)
kube-system weave-net-lwk8r 20m (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop carts-2469883122-h8f4n 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop carts-db-1721187500-pkpk0 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop catalogue-4293036822-hpkgp 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop catalogue-db-1846494424-xlb8m 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop front-end-2337481689-s8bkm 100m (1%) 0 (0%) 100Mi (1%) 0 (0%)
sock-shop orders-733484335-n7h4c 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop orders-db-3728196820-12rt8 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop payment-3050936124-kwqfs 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop queue-master-2067646375-n8sgj 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop rabbitmq-241640118-dqh6p 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop shipping-2463450563-g01sw 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop user-1574605338-kwqmp 0 (0%) 0 (0%) 0 (0%) 0 (0%)
sock-shop user-db-3152184577-w3f39 0 (0%) 0 (0%) 0 (0%) 0 (0%)
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.)
CPU Requests CPU Limits Memory Requests Memory Limits
------------ ---------- --------------- -------------
120m (1%) 0 (0%) 100Mi (1%) 0 (0%)
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
44m 44m 1 kubelet, node2-precision-t1600 Normal NodeReady Node node2-precision-t1600 status is now: NodeReady
44m 44m 3 kubelet, node2-precision-t1600 Normal NodeHasSufficientDisk Node node2-precision-t1600 status is now: NodeHasSufficientDisk
44m 44m 3 kubelet, node2-precision-t1600 Normal NodeHasSufficientMemory Node node2-precision-t1600 status is now: NodeHasSufficientMemory
44m 44m 3 kubelet, node2-precision-t1600 Normal NodeHasNoDiskPressure Node node2-precision-t1600 status is now: NodeHasNoDiskPressure
44m 44m 1 kubelet, node2-precision-t1600 Normal NodeAllocatableEnforced Updated Node Allocatable limit across pods
44m 44m 1 kubelet, node2-precision-t1600 Warning Rebooted Node node2-precision-t1600 has been rebooted, boot id: 827de455-66cb-481d-a362-557a17db11f4
44m 44m 1 kubelet, node2-precision-t1600 Normal Starting Starting kubelet.
44m 44m 1 kube-proxy, node2-precision-t1600 Normal Starting Starting kube-proxy.
43m 11m 9 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "rabbitmq-241640118-dqh6p_sock-shop(79e3bb08-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 5m 24 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "orders-db-3728196820-12rt8_sock-shop(79ca1e21-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 2m 22 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "payment-3050936124-kwqfs_sock-shop(79cb96f4-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 2m 28 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "shipping-2463450563-g01sw_sock-shop(79fa9dd4-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
43m 2m 22 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "carts-2469883122-h8f4n_sock-shop(79bbf964-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 1m 30 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "user-db-3152184577-w3f39_sock-shop(7a303582-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 1m 16 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "user-1574605338-kwqmp_sock-shop(7a11a937-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 1m 20 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "catalogue-db-1846494424-xlb8m_sock-shop(79c24789-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 54s 26 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "queue-master-2067646375-n8sgj_sock-shop(79d46bb2-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 45s 30 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "front-end-2337481689-s8bkm_sock-shop(79c49a6c-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
44m 24s 11 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "carts-db-1721187500-pkpk0_sock-shop(79bd1f99-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
43m 11s 25 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "catalogue-4293036822-hpkgp_sock-shop(79bf628c-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
43m 3s 25 kubelet, node2-precision-t1600 Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "orders-733484335-n7h4c_sock-shop(79c6f31c-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
43m 0s 228 kubelet, node2-precision-t1600 Warning MissingClusterDNS (combined from similar events): kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "payment-3050936124-kwqfs_sock-shop(79cb96f4-87e4-11e7-ab01-782bcba630bb)". Falling back to DNSDefault policy.
编辑 1：
正如迈克在他的回答中告诉我的那样，我得到了 DNS IP：kubectl get services --namespace=kube-system。到目前为止，我尝试更改命令行标志的事情：
- 将其添加到 ExecStart kubeadm.conf 中为 --cluster-dns 10.96.0.10
- Execute kubelet --cluster-dns 10.96.0.10
两者都没有结果
kubelet 服务需要一个命令行标志来设置集群 DNSIP - 看起来你正在运行 kube-dns，所以你可以通过运行kubectl get services --namespace=kube-system或从 kube-dns 服务 YAML 或 JSON 配置上的"ClusterIP"字段中获取 IP。
一旦你有了IP，你就需要为kubelet设置--cluster-dns命令行标志。
我没有使用 kubeadm 来设置集群，所以我不确定它如何运行服务，也不能说如何更改命令行标志 - 希望知道的人可以为该部分提供输入。