ubuntu16 kubernetes1.6安装（七、kubedns安装）

team470

　　本章中所使用的镜像为google资源，无法直接使用，本文为自行下载并上传到私有仓库:
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
其实国内也有部分镜像库把gcr.io 替换成gcr.mirrors.ustc.edu.cn就可以下载了
　　1、修改默认配置文件，本文把所有配置文件贴出来，其实拿官网的对照着改动下即可，关键要和自己环境预定义的一致，其实整个流程很简单，只是过程较多，容易混乱。
配置文件如下：
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.  此处的域为事先定义的
  - --dns-port=10053
  - --config-dir=/kube-dns-config
  - --v=2
  #__PILLAR__FEDERATIONS__DOMAIN__MAP__   #该行注释掉
  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为私有仓库中的
  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
  2、启动以及验证
  root# kubectl create -f .  启动所有组件
  首先验证kubedns的三个镜像是否正常
  

　　验证service是否存在，从下面命令看dns的service ip和预定义的一致，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
　　验证kubedns 的三个镜像是否正常，如发现pod状态为 2/3之类的，意味着有问题，具体可到相应node上使用docker logs xxxx 查看具体原因。
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
　　最后使用node节点部署的验证方法，启动一个nginx或者其他镜像都行，然后进入容器进行kubedns的测试
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
简要ping一下，看是否能够解析
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版本安装过程到此结束，后续插件dashboard同kubedns类似，仿照官网的配置文件进行修改。