Ingress是基于域名实现的一个负载均衡,其主要用来解决使用NodePort暴露Service的端口时Node IP会漂移的问题。同时,若大量使用NodePort暴露主机端口,管理会非常混乱。
好的解决方案就是让外界通过域名去访问Service,而无需关心其Node IP及Port。那为什么不直接使用Nginx?这是因为在K8S集群中,如果每加入一个服务,我们都在Nginx中添加一个配置,其实是一个重复性的体力活,只要是重复性的体力活,我们都应该通过技术将它干掉。
Ingress就可以解决上面的问题,其包含两个组件Ingress Controller和Ingress:
Ingress
将Nginx的配置抽象成一个Ingress对象,每添加一个新的服务只需写一个新的Ingress的yaml文件即可
Ingress Controller
将新加入的Ingress转化成Nginx的配置文件并使之生效
作者:宅楠军
链接:https://www.jianshu.com/p/feeea0bbd73e
来源:简书
简书著作权归作者所有,任何形式的转载都请联系作者获得授权并注明出处。
创建一个ingress-nginx
[root@k8s-master ingress]# cat ingress-nginx.yaml
apiVersion: v1
kind: Namespace
metadata:
name: 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
---
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 "-"
# Here: "-"
# 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
containers:
- name: nginx-ingress-controller
image: lizhenliang/nginx-ingress-controller:0.20.0
args:
- /nginx-ingress-controller
- --configmap=$(POD_NAMESPACE)/nginx-configuration
- --publish-service=$(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
这里有的执行完毕之后,可以ingress出现off状态,这里需要在你的kube-proxy配置文件添加--masquerade-all=true \
这里我是自己搭建的二进制k8s集群是这么添加的,其他的环境这里不做太多阐述
node节点都需要重启并添加参数
[root@k8s-node1 ~]# vim /opt/kubernetes/cfg/kube-proxy
KUBE_PROXY_OPTS="--logtostderr=true \
-v=4 \
-hostname-override=192.168.30.22 \
-cluster-cidr=10.0.0.0/24 \
-masquerade-all=true \
-kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"
重启kube-proxy和kube-apiserver就可以了,查看ingress
[root@k8s-master ~]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
nginx-ingress-controller-bbb66b76b-2jszm 1/1 Running 0 48m