ubuntu16 kubernetes1.6安装（七、kubedns安装）

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。