1. 程式人生 > >ingress基礎知識和deployment部署

ingress基礎知識和deployment部署

能夠 rpo aps The endpoint count mas 3.5 yam

1. ingress簡單介紹

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:

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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。

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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。


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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


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3.2部署configmap


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3.3default-backend.yaml


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[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


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[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


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[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


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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


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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


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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