ingress基礎知識和deployment部署
ingress由兩部分組成:ingress controller和ingress服務。
ingress controller通過和kubernetes api交互,動態的去感知集群中ingress規則變化,然後讀取它,按照自定義的規則,規則就是寫明了哪個域名對應哪個service,生成一段nginx配置,再寫到nginx-ingress-control的pod裏,這個Ingress controller的pod裏運行著一個Nginx服務,控制器會把生成的nginx配置寫入/etc/nginx.conf文件中,然後reload一下使配置生效。以此達到域名分配置和動態更新的問題。
2. ingress基礎知識
2.1 官網下載下來的文件:
下載目錄:
https://github.com/kubernetes/ingress-nginx/tree/master/deploy
2.2 配置文件簡易說明:
namespace.yaml
這個文件用來創建ingress-nginx的namespace,ingress-nginx的相關組件都將在這個namespace下。
configmap.yaml
ConfigMap是存儲通用的配置變量的,類似於配置文件,使用戶可以將分布式系統中用於不同模塊的環境變量統一到一個對象中管理;而它與配置文件的區別在於它是存在集群的“環境”中的,並且支持K8S集群中所有通用的操作調用方式。
從數據角度來看,ConfigMap的類型只是鍵值組,用於存儲被Pod或者其他資源對象(如RC)訪問的信息。這與secret的設計理念有異曲同工之妙,主要區別在於ConfigMap通常不用於存儲敏感信息,而只存儲簡單的文本信息。
ConfigMap可以保存環境變量的屬性,也可以保存配置文件。
創建pod時,對configmap進行綁定,pod內的應用可以直接引用ConfigMap的配置。相當於configmap為應用/運行環境封裝配置。
pod使用ConfigMap,通常用於:設置環境變量的值、設置命令行參數、創建配置文件。
後面可以看到這裏配置的configmap的使用情況。
default-backend.yaml
default-http-backend從名稱上來看即默認的後端,當集群外部的請求通過ingress進入到集群內部時,如果無法負載到相關後端的Service上,這種未知的請求將會被負載到這個默認的後端上。
[root@kubernetes1 ingress]# cat default-backend.yaml
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: default-http-backend
labels:
app: default-http-backend
namespace: ingress-nginx
spec:
replicas: 1
selector:
matchLabels:
app: default-http-backend
template:
metadata:
labels:
app: default-http-backend
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: gcr.io/google_containers/defaultbackend:1.4
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: default-http-backend
spec:
ports:
- port: 80
targetPort: 8080
selector:
app: default-http-backend
rbac.yaml
創建ServiceAccount nginx-ingress-serviceaccount,並創建相關的ClusterRole, Role, ClusterRoleBinding, RoleBinding以對其進行授權
簡易說明:
Service Account它並不是給kubernetes集群的用戶使用的,而是給pod裏面的進程使用的,它為pod提供必要的身份認證。
[root@kubernetes1 ingress]# cat rbac.yaml
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
name: nginx-ingress-clusterrole
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
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
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
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: nginx-ingress-clusterrole
subjects:
- kind: ServiceAccount
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
with-rbac.yaml
這是nginx-ingress-controller
簡易說明:
serviceAccountName: nginx-ingress-serviceaccount
這是用前面配置的serviceAccount
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=$(POD_NAMESPACE)/ingress-nginx
- --annotations-prefix=nginx.ingress.kubernetes.io
這裏引用到了configmap
[root@kubernetes1 ingress]# cat with-rbac.yaml
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-ingress-controller
namespace: ingress-nginx
spec:
replicas: 1
selector:
matchLabels:
app: ingress-nginx
template:
metadata:
labels:
app: ingress-nginx
annotations:
prometheus.io/port: '10254'
prometheus.io/scrape: 'true'
spec:
serviceAccountName: nginx-ingress-serviceaccount
containers:
- name: nginx-ingress-controller
image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.17.1
args:
- /nginx-ingress-controller
- --default-backend-service=$(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
3.部署ingress
3.1部署namespace.yaml
3.2部署configmap
3.3default-backend.yaml
[root@kubernetes1 ingress]# kubectl get pod,svc -n ingress-nginx
NAME READY STATUS RESTARTS AGE
pod/default-http-backend-5c6d95c48-lp6n4 1/1 Running 0 1m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/default-http-backend ClusterIP 10.97.96.55 <none> 80/TCP 1m
[root@kubernetes1 ingress]# kubectl get pod,svc -n ingress-nginx
NAME READY STATUS RESTARTS AGE
pod/default-http-backend-5c6d95c48-lp6n4 1/1 Running 0 1m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/default-http-backend ClusterIP 10.97.96.55 <none> 80/TCP 1m
[root@kubernetes1 ingress]#
3.4部署serviceaccount
[root@kubernetes1 ingress]# kubectl get sa -n ingress-nginx
NAME SECRETS AGE
default 1 9m
nginx-ingress-serviceaccount 1 2m
[root@kubernetes1 ingress]#
詳細信息見下:
[root@kubernetes1 ingress]# kubectl get sa -n ingress-nginx -o yaml
apiVersion: v1
items:
- apiVersion: v1
kind: ServiceAccount
metadata:
creationTimestamp: 2018-07-19T06:17:28Z
name: default
namespace: ingress-nginx
resourceVersion: "825666"
selfLink: /api/v1/namespaces/ingress-nginx/serviceaccounts/default
uid: 69a2d6ae-8b1b-11e8-9311-000c292f3b91
secrets:
- name: default-token-wfz4v
- apiVersion: v1
kind: ServiceAccount
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","kind":"ServiceAccount","metadata":{"annotations":{},"name":"nginx-ingress-serviceaccount","namespace":"ingress-nginx"}}
creationTimestamp: 2018-07-19T06:24:21Z
name: nginx-ingress-serviceaccount
namespace: ingress-nginx
resourceVersion: "826276"
selfLink: /api/v1/namespaces/ingress-nginx/serviceaccounts/nginx-ingress-serviceaccount
uid: 5f733ebe-8b1c-11e8-9311-000c292f3b91
secrets:
- name: nginx-ingress-serviceaccount-token-4vzm8
kind: List
metadata:
resourceVersion: ""
selfLink: ""
[root@kubernetes1 ingress]#
3.5部署ingress-controller這裏是with-rbac.yaml
[root@kubernetes1 ingress]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
default-http-backend-5c6d95c48-lp6n4 1/1 Running 0 13m
nginx-ingress-controller-d774fd595-8w7lp 1/1 Running 0 1m
[root@kubernetes1 ingress]#
3.6創建為nginx-ingress-controller創建一個Service並暴露到集群外邊
externalIPs
external-ip指的是對外暴露的ip地址,一般用公網IP地址,執行那個命令過後,我們就可以在公網上訪問了,
但是這裏有個問題就是這個IP地址必須是安裝了k8s的機器的IP,如果你隨便用一個IP是不能訪問的.
[root@kubernetes1 wp]# cat ../ingress/ingress-nginx.svc.yaml
apiVersion: v1
kind: Service
metadata:
name: ingress-nginx
namespace: ingress-nginx
spec:
externalIPs:
- 192.168.211.151
- 192.168.211.152
ports:
- name: http
port: 80
targetPort: 80
protocol: TCP
- name: https
port: 443
targetPort: 443
protocol: TCP
selector:
app: ingress-nginx
[root@kubernetes1 wp]#
[root@kubernetes1 wp]# kubectl get svc -n ingress-nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default-http-backend ClusterIP 10.97.96.55 <none> 80/TCP 7h
ingress-nginx ClusterIP 10.110.12.208 192.168.211.151,192.168.211.152 80/TCP,443/TCP 5m
[root@kubernetes1 wp]#
[root@kubernetes1 wp]# curl 192.168.211.151:80
default backend - 404[root@kubernetes1 wp]#
[root@kubernetes1 wp]# curl 192.168.211.152:80
default backend - 404[root@kubernetes1 wp]#
[root@kubernetes1 wp]#
如果以上都顯示正常,ingress部署完成了。
4.實踐:通過ingress訪問部署好的服務
綜述:
部署好了wordpress,也部署好了ingress,配置通過ingress訪問wordpress。
4.1.wordpress詳情
4.2.ingress跳轉wordpress的規則
簡易說明:
spec:
rules:
- host: wordpress.ingress
http:
paths:
- path: /
backend:
serviceName: wordpress
servicePort: 8080
host: wordpress.ingress ##這是前端隨便配置的一個用來訪問的域名
serviceName: wordpress
servicePort: 8080 ##這是指定後端的service和service的監聽端口
4.3.執行規則
[root@kubernetes1 wp]# kubectl apply -f wordpress.ingress.yaml
ingress.extensions "wordpress" created
[root@kubernetes1 wp]#
[root@kubernetes1 wp]# kubectl get ing -o wide
NAME HOSTS ADDRESS PORTS AGE
wordpress wordpress.ingress 80 44s
[root@kubernetes1 wp]# kubectl describe ing
Name: wordpress
Namespace: default
Address:
Default backend: default-http-backend:80 (<none>)
Rules:
Host Path Backends
---- ---- --------
wordpress.ingress
/ wordpress:8080 (<none>)
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{},"name":"wordpress","namespace":"default"},"spec":{"rules":[{"host":"wordpress.ingress","http":{"paths":[{"backend":{"serviceName":"wordpress","servicePort":8080},"path":"/"}]}}]}}
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal CREATE 57s nginx-ingress-controller Ingress default/wordpress
[root@kubernetes1 wp]#
4.4.訪問
我用來測試訪問的是win7系統,首先需要修改host,保證能夠解析wordpress.ingress到正確的ip地址
我解析到192.168.211.152
解析成功後,瀏覽器直接訪問這個地址即可
4.5.參考文檔
https://blog.frognew.com/2018/06/kubernetes-ingress-1.html
ingress基礎知識和deployment部署