ubuntu16 kubernetes1.6安裝（7、kubedns安裝）

本章中所使用的鏡像爲google資源，沒法直接使用，本文爲自行下載並上傳到私有倉庫:
gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64:1.14.1
gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.1
gcr.io/google_containers/k8s-dns-sidecar-amd64:1.14.1
其實國內也有部分鏡像庫把gcr.io 替換成gcr.mirrors.ustc.edu.cn就能夠下載了

一、修改默認配置文件，本文把全部配置文件貼出來，其實拿官網的對照着改動下便可，關鍵要和本身環境預約義的一致，其實整個流程很簡單，只是過程較多，容易混亂。
配置文件以下：
root@ubuntu132:~/dnsyaml# ls
kubedns-cm.yaml kubedns-controller.yaml kubedns-sa.yaml kubedns-svc.yaml

root@ubuntu132:~/dnsyaml# cat kubedns-cm.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: kube-dns
namespace: kube-system
labels:
addonmanager.kubernetes.io/mode: EnsureExists

root@ubuntu132:~/dnsyaml# cat kubedns-controller.yaml
apiVersion: extensions/v1beta1
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:

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: docker.xxx.com:5000/k8s-dns-kube-dns-amd64:v1.14.1
  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.  此處的域爲事先定義的
  - --dns-port=10053
  - --config-dir=/kube-dns-config
  - --v=2
  #__PILLAR__FEDERATIONS__DOMAIN__MAP__   #該行註釋掉
  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: docker.xxx.com:5000/k8s-dns-dnsmasq-nanny-amd64:v1.14.1 #image爲私有倉庫中的
  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
  • --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: docker.xxx.com:5000/k8s-dns-sidecar-amd64:v1.14.1
  livenessProbe:
  httpGet:
  path: /metrics
  port: 10054
  scheme: HTTP
  initialDelaySeconds: 60
  timeoutSeconds: 5
  successThreshold: 1
  failureThreshold: 5
  args:

  • --v=2
  • --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local,5,A
  • --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local,5,A
    ports:
  • containerPort: 10054
    name: metrics
    protocol: TCP
    resources:
    requests:
    memory: 20Mi
    cpu: 10m
    dnsPolicy: Default # Don't use cluster DNS.
    serviceAccountName: kube-dns

  root@ubuntu132:~/dnsyaml# cat kubedns-sa.yaml
  apiVersion: v1
  kind: ServiceAccount
  metadata:
  name: kube-dns
  namespace: kube-system
  labels:
  kubernetes.io/cluster-service: "true"
  addonmanager.kubernetes.io/mode: Reconcile
  root@ubuntu132:~/dnsyaml# cat kubedns-svc.yaml
  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: 10.254.0.2
  ports:

  • name: dns
    port: 53
    protocol: UDP
  • name: dns-tcp
    port: 53
    protocol: TCP

root@ubuntu132:~/dnsyaml# cat kubedns-svc.yaml
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: 10.254.0.2
ports:

• name: dns
  port: 53
  protocol: UDP
• name: dns-tcp
  port: 53
  protocol: TCP
  二、啓動以及驗證
  root# kubectl create -f . 啓動全部組件
  首先驗證kubedns的三個鏡像是否正常

驗證service是否存在，從下面命令看dns的service ip和預約義的一致，svc正常
root@ubuntu132:~/dnsyaml# kubectl get svc kube-dns --namespace=kube-system
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kube-dns 10.254.0.2 <none> 53/UDP,53/TCP 6d

驗證kubedns 的三個鏡像是否正常，如發現pod狀態爲 2/3之類的，意味着有問題，具體可到相應node上使用docker logs xxxx 查看具體緣由。
root@ubuntu132:~/dnsyaml# kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME READY STATUS RESTARTS AGE
kube-dns-2598890466-xc0xd 3/3 Running 37 6d

最後使用node節點部署的驗證方法，啓動一個nginx或者其餘鏡像都行，而後進入容器進行kubedns的測試
root@ubuntu132:~/dnsyaml# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-2958629218-44rcm 1/1 Running 0 15h
nginx-2958629218-qd5rt 1/1 Running 0 15h
root@ubuntu132:~/dnsyaml# kubectl exec -it nginx-2958629218-44rcm /bin/bash
簡要ping一下，看是否可以解析
root@nginx-2958629218-44rcm:/# ping kubernetes
PING kubernetes.default.svc.cluster.local (10.254.0.1): 56 data bytes
^C--- kubernetes.default.svc.cluster.local ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss
root@nginx-2958629218-44rcm:/# ping kube-dns.kube-system.svc.cluster.local
PING kube-dns.kube-system.svc.cluster.local (10.254.0.2): 56 data bytes
^C--- kube-dns.kube-system.svc.cluster.local ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss

至此kubernetes1.6.4版本安裝過程到此結束，後續插件dashboard同kubedns相似，仿照官網的配置文件進行修改。