一、k8s的暴露服务的方式存在很多种,为啥要选择ingress呢?
二、k8s之Service
apiVersion: v1
kind: Service
metadata:
name: xbd-nacos
spec:
ports:
- port: 8848
targetPort: 8848
selector:
app: xbd-nacos
type: ClusterIP
类型:
1)ClusterIP:默认的,仅在集群内可用。
2)NodePort:暴露端口到节点,提供了集群外部访问的入口,端口范围固定 30000 ~ 32767。
3)LoadBalancer:使用支持外部负载均衡器的云提供商的服务,设置 type 的值为 "LoadBalancer",将为 Service 提供负载均衡器。 负载均衡器是异步创建的,关于被提供的负载均衡器的信息将会通过 Service 的 status.loadBalancer 字段被发布出去。
4)Headless:适合数据库。clusterIp 设置为 None 就变成 Headless 了,不会再分配 IP。
ExternalName:把集群外部的服务引入到集群内部来,在集群内部直接使用。没有任何类型代理被创建,这只有 Kubernetes 1.7或更高版本的kube-dns才支持。
三、不使用service来做暴露的原因
Service能够提供负载均衡的能力,但是在使用上有以下限制:只提供 4 层负载均衡能力,而没有 7 层功能,但有时我们可能需要更多的匹配规则来转发请求,这点上 4 层负载均衡是不支持的。
Service理解:Kubernetes Service定义了这样一种抽象: Service是一种可以访问 Pod逻辑分组的策略, Service通常是通过 Label Selector访问 Pod组。
四、Ingress
Ingress 为外部访问集群提供了一个 统一 入口,避免了对外暴露集群端口;功能类似 Nginx,可以根据域名、路径把请求转发到不同的 Service。
ingress理解:基本上就看成nginx就行了。
五、Ingress安装
1)安装ingress控制器,由于ingress默认是不存在控制器的,所以需要自己安装ingress控制器。
控制器类型:Kubernetes、NGINX、Kong、Traefik、HAProxy、Voyager、Contour、Istio、Ambassador、Gloo、Skipper等
2)这里我们选择最熟悉的nginx来作为我们的控制器,官网地址和版本选择
地址:https://kubernetes.github.io/ingress-nginx/
github地址:https://github.com/kubernetes/ingress-nginx
版本:(因为我k8s的版本使用的是1.20.x,所有我选择的版本是v1.1.3)
3)安装ingress-nginx-controller
下载应用文件:
https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.1.3/deploy/static/provider/cloud/deploy.yaml
下载后不能直接使用,主要是镜像和一些配置需要修改。
修改后:
apiVersion: v1
kind: Namespace
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
name: ingress-nginx
---
apiVersion: v1
automountServiceAccountToken: true
kind: ServiceAccount
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx
namespace: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- namespaces
verbs:
- get
- apiGroups:
- ""
resources:
- configmaps
- pods
- secrets
- endpoints
verbs:
- get
- list
- watch
- apiGroups:
- ""
resources:
- services
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses/status
verbs:
- update
- apiGroups:
- networking.k8s.io
resources:
- ingressclasses
verbs:
- get
- list
- watch
- apiGroups:
- ""
resourceNames:
- ingress-controller-leader
resources:
- configmaps
verbs:
- get
- update
- apiGroups:
- ""
resources:
- configmaps
verbs:
- create
- apiGroups:
- ""
resources:
- events
verbs:
- create
- patch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
namespace: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- secrets
verbs:
- get
- create
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- configmaps
- endpoints
- nodes
- pods
- secrets
- namespaces
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes
verbs:
- get
- apiGroups:
- ""
resources:
- services
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses
verbs:
- get
- list
- watch
- apiGroups:
- ""
resources:
- events
verbs:
- create
- patch
- apiGroups:
- networking.k8s.io
resources:
- ingresses/status
verbs:
- update
- apiGroups:
- networking.k8s.io
resources:
- ingressclasses
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
rules:
- apiGroups:
- admissionregistration.k8s.io
resources:
- validatingwebhookconfigurations
verbs:
- get
- update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx
namespace: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: ingress-nginx
subjects:
- kind: ServiceAccount
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
namespace: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: ingress-nginx-admission
subjects:
- kind: ServiceAccount
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: ingress-nginx
subjects:
- kind: ServiceAccount
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: ingress-nginx-admission
subjects:
- kind: ServiceAccount
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: v1
data:
allow-snippet-annotations: "true"
kind: ConfigMap
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-controller
namespace: ingress-nginx
---
apiVersion: v1
kind: Service
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
externalTrafficPolicy: Local
ports:
- appProtocol: http
name: http
port: 80
protocol: TCP
targetPort: http
- appProtocol: https
name: https
port: 443
protocol: TCP
targetPort: https
selector:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-controller-admission
namespace: ingress-nginx
spec:
ports:
- appProtocol: https
name: https-webhook
port: 443
targetPort: webhook
selector:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
type: ClusterIP
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
minReadySeconds: 0
revisionHistoryLimit: 10
selector:
matchLabels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
template:
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
spec:
hostNetwork: true
containers:
- args:
- /nginx-ingress-controller
- --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
- --election-id=ingress-controller-leader
- --controller-class=k8s.io/ingress-nginx
- --ingress-class=nginx
- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
- --validating-webhook=:8443
- --validating-webhook-certificate=/usr/local/certificates/cert
- --validating-webhook-key=/usr/local/certificates/key
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: LD_PRELOAD
value: /usr/local/lib/libmimalloc.so
image: registry.aliyuncs.com/google_containers/nginx-ingress-controller:v1.1.3
imagePullPolicy: IfNotPresent
lifecycle:
preStop:
exec:
command:
- /wait-shutdown
livenessProbe:
failureThreshold: 5
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
name: controller
ports:
- containerPort: 80
name: http
protocol: TCP
- containerPort: 443
name: https
protocol: TCP
- containerPort: 8443
name: webhook
protocol: TCP
readinessProbe:
failureThreshold: 3
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
resources:
requests:
cpu: 100m
memory: 90Mi
securityContext:
allowPrivilegeEscalation: true
capabilities:
add:
- NET_BIND_SERVICE
drop:
- ALL
runAsUser: 101
volumeMounts:
- mountPath: /usr/local/certificates/
name: webhook-cert
readOnly: true
dnsPolicy: ClusterFirst
nodeSelector:
kubernetes.io/os: linux
serviceAccountName: ingress-nginx
terminationGracePeriodSeconds: 300
volumes:
- name: webhook-cert
secret:
secretName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission-create
namespace: ingress-nginx
spec:
template:
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission-create
spec:
containers:
- args:
- create
- --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc
- --namespace=$(POD_NAMESPACE)
- --secret-name=ingress-nginx-admission
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
image: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1
imagePullPolicy: IfNotPresent
name: create
securityContext:
allowPrivilegeEscalation: false
nodeSelector:
kubernetes.io/os: linux
restartPolicy: OnFailure
securityContext:
fsGroup: 2000
runAsNonRoot: true
runAsUser: 2000
serviceAccountName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission-patch
namespace: ingress-nginx
spec:
template:
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission-patch
spec:
containers:
- args:
- patch
- --webhook-name=ingress-nginx-admission
- --namespace=$(POD_NAMESPACE)
- --patch-mutating=false
- --secret-name=ingress-nginx-admission
- --patch-failure-policy=Fail
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
image: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1
imagePullPolicy: IfNotPresent
name: patch
securityContext:
allowPrivilegeEscalation: false
nodeSelector:
kubernetes.io/os: linux
restartPolicy: OnFailure
securityContext:
fsGroup: 2000
runAsNonRoot: true
runAsUser: 2000
serviceAccountName: ingress-nginx-admission
---
apiVersion: networking.k8s.io/v1
kind: IngressClass
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: nginx
spec:
controller: k8s.io/ingress-nginx
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.1.3
name: ingress-nginx-admission
webhooks:
- admissionReviewVersions:
- v1
clientConfig:
service:
name: ingress-nginx-controller-admission
namespace: ingress-nginx
path: /networking/v1/ingresses
failurePolicy: Fail
matchPolicy: Equivalent
name: validate.nginx.ingress.kubernetes.io
rules:
- apiGroups:
- networking.k8s.io
apiVersions:
- v1
operations:
- CREATE
- UPDATE
resources:
- ingresses
sideEffects: None
View Code
主要修改点:
镜像
image: k8s.gcr.io/ingress-nginx/controller:v1.1.3@sha256:31f47c1e202b39fadecf822a9b76370bd4baed199a005b3e7d4d1455f4fd3fe2
改成
image: registry.aliyuncs.com/google_containers/nginx-ingress-controller:v1.1.3
image: k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1@sha256:64d8c73dca984af206adf9d6d7e46aa550362b1d7a01f3a0a91b20cc67868660
改成(这个镜像存在两处)
image: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1
配置
ingress-nginx-controller中的
kind: Deployment
改成
kind: DaemonSet # 保证每个节点都存在
---
spec:
containers:
...
加入
spec:
hostNetwork: true # 宿主网络开启
containers:
...
4)执行安装
kubectl apply -f deploy.yaml
五、编写Ingress
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: xbd-nacos-ing
spec:
ingressClassName: "nginx"
rules:
- host: xbd.nacos.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: xbd-nacos
port:
number: 8848
应用
kubectl apply -f xbd-nacos-ing.yaml
六、hosts加入
192.168.5.201 xbd.nacos.com
七、测试:
八、代理前缀处理
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: xbd-nacos-ing
spec:
ingressClassName: "nginx"
nginx.ingress.kubernetes.io/configuration-snippet: |
rewrite ^/nacos/(.*)$ /$1 break;
rules:
- host: xbd.nacos.com
http:
paths:
- path: /nacos
pathType: Prefix
backend:
service:
name: xbd-nacos
port:
number: 8848