1.定义ingress前，必须先部署ingress controller ，以实现为所有后端的service 提供一个统一的入口。在ingress-controller的rc文件中定义了一个默认后端。所以在部署ingress controller前要先启动默认后端的pod，否则启动ingress-controller会不成功.
default-http-backend.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: default-http-backend
spec:
  replicas: 1
  selector:
    app: default-http-backend
  template:
    metadata:
      labels:
        app: default-http-backend
    spec:
      terminationGracePeriodSeconds: 60
      containers:
      - name: default-http-backend
        # Any image is permissable as long as:
        # 1. It serves a 404 page at /
        # 2. It serves 200 on a /healthz endpoint
        image: index.tenxcloud.com/google_containers/defaultbackend:1.0
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          timeoutSeconds: 5
        ports:
        - containerPort: 8080
        resources:
          limits:
            cpu: 10m
            memory: 20Mi
          requests:
            cpu: 10m
            memory: 20Mi

kubectl expose rc default-http-backend --port=80 --target-port=8080 --name=default-http-backend

ingress-controller.yaml

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: nginx-ingress-lb
  labels:
    name: nginx-ingress-lb
  namespace: kube-system
spec:
  template:
    metadata:
      labels:
        name: nginx-ingress-lb
#      annotations:
#        prometheus.io/port: '80'
#        prometheus.io/scrape: 'true'
    spec:
      terminationGracePeriodSeconds: 60
      hostNetwork: true
      containers:
      - image: index.tenxcloud.com/google_containers/nginx-ingress-controller:0.8.3
        name: nginx-ingress-lb
        readinessProbe:
          httpGet:
            path: /healthz    #定义ingress-controller自检的url 和端口
            port: 80
            scheme: HTTP
        livenessProbe:
          httpGet:
            path: /healthz
            port: 80
            scheme: HTTP
          initialDelaySeconds: 10
          timeoutSeconds: 1
        ports:
        - containerPort: 80
          hostPort: 80
        - containerPort: 443
          hostPort: 443
        env:
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: KUBERNETES_MASTER
            value: http://192.168.23.128:8080      #访问master 获取service信息
        args:
        - /nginx-ingress-controller
        - --default-backend-service=default/default-http-backend

启动ingress-controller之后
可以根据需要暴露的服务配置ingress规则
以下是我测试的服务
rails-rc.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: rails
  labels:
    name: rails
spec:
  replicas: 1
  selector:
    name: rails
  template:
    metadata:
      labels:
        name: rails
    spec:
      containers:
        - name: rails
          image: index.tenxcloud.com/docker_library/rails
          imagePullPolicy: IfNotPresent
          command: [ "rails","server","-b","0.0.0.0"]

rails-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: rails
  labels:
    name: rails
spec:
  selector:
    name: rails
  ports:
  - port: 3000
    targetPort: 3000

ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: rails-ingress
spec:
  rules:
     - http:
        paths:
        - path: /rails
          backend:
            serviceName: rails
            servicePort: 3000

访问方法 http://nodeip/rails
代理到后端的rails 服务
可以通过kubectl describe ing rails查看具体规则
也可以通过直接进入ingress-controller容器中查看其中的/etc/nginx/nginx_conf 里面有没有自动生成配置规则。
ps daemonset 如果删不掉可能有结点挂了。启动daemonset之后没有个node结点都会启动ingress-controller容器。所以也可以设置ingress-controller为deployment
参考文档：http://blog.csdn.net/u013812710/article/details/52801656
https://github.com/kubernetes/ingress/blob/master/controllers/nginx/README.md#https

tls -ingress

mkdir /etc/kubernetes/ssl
cd /etc/kubernetes/ssl
openssl genrsa -out ca-key.pem 2048
openssl req -x509 -new -nodes -key ca-key.pem -days 10000 -out ca.pem -subj "/CN=kube-ca"
cat >>  openssl.cnf << EOF
[req]
req_extensions = v3_req
distinguished_name = req_distinguished_name
[req_distinguished_name]
[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
subjectAltName = @alt_names
[alt_names]
DNS = dashboard.yiwu.com
IP.1 = 10.254.0.1   #k8s 集群service ip
IP.2 = 192.168.23.128  
EOF
openssl genrsa -out ingress-key.pem 2048
openssl req -new -key ingress-key.pem -out ingress.csr -subj "/CN=dashboard.yiwu.com" -config openssl.cnf
openssl x509 -req -in ingress.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out ingress.pem -days 365 -extensions v3_req -extfile openssl.cnf
kubectl create secret tls ingress-secret --key ingress-key.pem --cert ingress.pem  -n kube-system
kubectl create -f /opt/docker/conf/dashboard/dashboard-ingress-tls.yaml

dashboard-ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: k8s-dashboard
  namespace: kube-system
spec:
  tls:
  - hosts:
    - dashboard.yiwu.com
    secretName: ingress-secret
  rules:
  - host: dashboard.yiwu.com
    http:
      paths:
      - backend:
          serviceName: kubernetes-dashboard
          servicePort: 80
        path: /

openssl x509 -noout -test -in /etc/kubernetes/ssl/ingress.pem
curl https://dashboard.yiwu.com -v --cert /etc/kubernetes/ssl/ingress.pem --key /etc/kubernetes/ssl/ingress-key.pem --cacert /etc/kubernetes/ssl/ca.pem
curl https://dashboard.yiwu.com -v -k

参考：https://my.oschina.net/lemonzone2010/blog/467213?p=1

ingress 重写规则
参考：https://github.com/kubernetes/ingress/tree/master/examples/rewrite/nginx
例子：

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    ingress.kubernetes.io/rewrite-target: /
  name: rewrite
  namespace: default
spec:
  rules:
  - host: rewrite.bar.com
    http:
      paths:
      - backend:
          serviceName: echoheaders
          servicePort: 80
        path: /something