Ingress` entrance is actually from a cluster kuberenets external access to the cluster to forward external requests to different Service within a cluster, in fact, equivalent to nginx, haproxy such as load balancing proxy server, Ingress controller can be understood as a listener, by constantly dealing with kube-apiserver, real-time perception back-end service, change pod, and when these changes get information, Ingress controller combined Ingress configuration, update the reverse proxy load balancer, to the role of service discovery.
In Kubernetes currently offers the following programs:
NodePort
LoadBalancer
Ingress
Use ingress-nginx, create pod service, the default file yaml
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/mandatory.yaml
vim mandatory.yaml
apiVersion: v1
kind: Namespace
metadata:
name: ingress-nginx
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: default-http-backend
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
namespace: ingress-nginx
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
template:
metadata:
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
spec:
terminationGracePeriodSeconds: 60
containers:
- name: default-http-backend
# Any image is permissible as long as:
# 1. It serves a 404 page at /
# 2. It serves 200 on a /healthz endpoint
image: k8s.gcr.io/defaultbackend-amd64:1.5
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
---
apiVersion: v1
kind: Service
metadata:
name: default-http-backend
namespace: ingress-nginx
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
spec:
ports:
- port: 80
targetPort: 8080
selector:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
name: nginx-configuration
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
name: tcp-services
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
---
kind: ConfigMap
apiVersion: v1
metadata:
name: udp-services
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
name: nginx-ingress-clusterrole
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- configmaps
- endpoints
- nodes
- pods
- secrets
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes
verbs:
- get
- apiGroups:
- ""
resources:
- services
verbs:
- get
- list
- watch
- apiGroups:
- "extensions"
resources:
- ingresses
verbs:
- get
- list
- watch
- apiGroups:
- ""
resources:
- events
verbs:
- create
- patch
- apiGroups:
- "extensions"
resources:
- ingresses/status
verbs:
- update
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
name: nginx-ingress-role
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- configmaps
- pods
- secrets
- namespaces
verbs:
- get
- apiGroups:
- ""
resources:
- configmaps
resourceNames:
# Defaults to "<election-id>-<ingress-class>"
# Here: "<ingress-controller-leader>-<nginx>"
# This has to be adapted if you change either parameter
# when launching the nginx-ingress-controller.
- "ingress-controller-leader-nginx"
verbs:
- get
- update
- apiGroups:
- ""
resources:
- configmaps
verbs:
- create
- apiGroups:
- ""
resources:
- endpoints
verbs:
- get
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
name: nginx-ingress-role-nisa-binding
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: nginx-ingress-role
subjects:
- kind: ServiceAccount
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: nginx-ingress-clusterrole-nisa-binding
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: nginx-ingress-clusterrole
subjects:
- kind: ServiceAccount
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-ingress-controller
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
template:
metadata:
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
annotations:
prometheus.io/port: "10254"
prometheus.io/scrape: "true"
spec:
serviceAccountName: nginx-ingress-serviceaccount
hostNetwork: true
nodeSelector:
app: ingress
containers:
- name: nginx-ingress-controller
image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.20.0
args:
- /nginx-ingress-controller
- --default-backend-service=$(POD_NAMESPACE)/default-http-backend
- --configmap=$(POD_NAMESPACE)/nginx-configuration
- --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
- --udp-services-configmap=$(POD_NAMESPACE)/udp-services
- --publish-service=$(POD_NAMESPACE)/ingress-nginx
- --annotations-prefix=nginx.ingress.kubernetes.io
securityContext:
capabilities:
drop:
- ALL
add:
- NET_BIND_SERVICE
# www-data -> 33
runAsUser: 33
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
ports:
- name: http
containerPort: 80
- name: https
containerPort: 443
livenessProbe:
failureThreshold: 3
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
readinessProbe:
failureThreshold: 3
httpGet:
path: /healthz
port: 10254
scheme: HTTP
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
---
The drift is fixed to the ingress node node02
[root@master ingress-nginx]# kubectl get no
NAME STATUS ROLES AGE VERSION
master Ready master 9d v1.10.0
node02 Ready <none> 8d v1.10.0
To node02 node marked lable label, set hostNetwork: true to improve the efficiency of network access
kubectl label node node02 app=ingress
yaml file configured, lable label also began to lay create ingress
kubectl apply -f mandatory.yaml
View pod status
[root@master ingress-nginx]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
default-http-backend-66c4fbf5b4-vkrzq 1/1 Running 4 21h
nginx-ingress-controller-658cd45944-tqgvm 1/1 Running 1 21h
# default
如果外界访问的域名不存在的话,则默认转发到default-http-backend这个Service,其会直接返回404:
I create a ingress-demo test, first create tomcat
---
# deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: tomcat-demo
spec:
selector:
matchLabels:
app: tomcat-demo
replicas: 1
template:
metadata:
labels:
app: tomcat-demo
spec:
containers:
- name: tomcat-demo
image: registry.cn-hangzhou.aliyuncs.com/liuyi01/tomcat:8.0.51-alpine
ports:
- containerPort: 8080
---
# service
apiVersion: v1
kind: Service
metadata:
name: tomcat-demo
spec:
ports:
- port: 80
protocol: TCP
targetPort: 8080
selector:
app: tomcat-demo
---
#ingress
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: tomcat-demo
spec:
rules:
- host: ingress1.com
http:
paths:
- path: /
backend:
serviceName: tomcat-demo
servicePort: 8080
In nginx create a service test
# deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: tomcat-demo
spec:
selector:
matchLabels:
app: tomcat-demo
replicas: 1
template:
metadata:
labels:
app: tomcat-demo
spec:
containers:
- name: tomcat-demo
image: registry.cn-hangzhou.aliyuncs.com/liuyi01/tomcat:8.0.51-alpine
ports:
- containerPort: 8080
---
# service
apiVersion: v1
kind: Service
metadata:
name: tomcat-demo
spec:
ports:
- port: 80
protocol: TCP
targetPort: 8080
selector:
app: tomcat-demo
---
#ingress
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: tomcat-demo
spec:
rules:
- host: ingress2.com
http:
paths:
- path: /
backend:
serviceName: tomcat-demo
servicePort: 8080
Creating nginx and tomcat pod Services
[root@master nginx-ingress]# kubectl apply -f .
# 查看pod情况,服务都起来了
[root@master nginx-ingress]# kubectl get pod
NAME READY STATUS RESTARTS AGE
load-generator-7bbbb4fdd4-l5vmz 1/1 Running 9 8d
myapp-deploy-6b9c9f847c-d6fsp 1/1 Running 0 2h
mynginx-85f8f5d89c-mhhzc 1/1 Running 0 2h
nginx-demo-6c5d64fd5f-xnscz 1/1 Running 0 1h
testservice-796fbc64bb-bczbs 1/1 Running 8 7d
tomcat-demo-686b48d96c-zxfpt 1/1 Running 0 2h
DNS configuration, the current test environment we use hosts file is parsed
192.168.14.32 ingress1.com
192.168.14.32 ingress2.com
Next to visit different domain name, get a different service