Kubernetes K8S 1.20部署Ingress nginx 0.30
主机配置规划
| 服务器名称(hostname) | 系统版本 | 配置 | 内网IP | 外网IP(模拟) |
|---|---|---|---|---|
| k8s-master | CentOS7.7 | 2C/4G/20G | 172.16.1.110 | 10.0.0.110 |
| k8s-node01 | CentOS7.7 | 2C/4G/20G | 172.16.1.111 | 10.0.0.111 |
| k8s-node02 | CentOS7.7 | 2C/4G/20G | 172.16.1.112 | 10.0.0.112 |
Ingress概述
Ingress 是对集群中服务的外部访问进行管理的 API 对象，典型的访问方式是 HTTP和HTTPS。
Ingress 可以提供负载均衡、SSL 和基于名称的虚拟托管。
必须具有 ingress 控制器【例如 ingress-nginx】才能满足 Ingress 的要求。仅创建 Ingress 资源无效。
Ingress 是什么
Ingress 公开了从集群外部到集群内 services 的 HTTP 和 HTTPS 路由。 流量路由由 Ingress 资源上定义的规则控制。
1 internet 2 | 3 [ Ingress ] 4 --|-----|-- 5 [ Services ]
可以将 Ingress 配置为提供服务外部可访问的 URL、负载均衡流量、 SSL / TLS，以及提供基于名称的虚拟主机。Ingress 控制器 通常负责通过负载均衡器来实现 Ingress，尽管它也可以配置边缘路由器或其他前端来帮助处理流量。
Ingress 不会公开任意端口或协议。若将 HTTP 和 HTTPS 以外的服务公开到 Internet 时，通常使用 Service.Type=NodePort 或者 Service.Type=LoadBalancer 类型的服务。
以Nginx Ingress为例，图如下
Ingress示例
架构图
部署Ingress-Nginx
该Nginx是经过改造的，而不是传统的Nginx。
Ingress-Nginx官网地址
https://kubernetes.github.io/ingress-nginx/
Ingress-Nginx GitHub地址
https://github.com/kubernetes/ingress-nginx
本次下载版本：nginx-0.30.0
镜像下载与重命名
1 docker pull registry.cn-beijing.aliyuncs.com/google_registry/nginx-ingress-controller:0.30.0 2 docker tag 89ccad40ce8e quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.30.0 3 docker rmi registry.cn-beijing.aliyuncs.com/google_registry/nginx-ingress-controller:0.30.0
ingress-nginx的yaml文件修改后并启动
1 # 当前目录 2 [root@k8s-master ingress]# pwd 3 /root/k8s_practice/ingress 4 # 获取NGINX: 0.30.0 5 [root@k8s-master ingress]# wget https://github.com/kubernetes/ingress-nginx/archive/nginx-0.30.0.tar.gz 6 [root@k8s-master ingress]# tar xf nginx-0.30.0.tar.gz 7 # yaml文件在下载包中的位置：ingress-nginx-nginx-0.30.0/deploy/static/mandatory.yaml 8 [root@k8s-master ingress]# cp -a ingress-nginx-nginx-0.30.0/deploy/static/mandatory.yaml ./ 9 [root@k8s-master ingress]# 10 # yaml文件配置修改 11 [root@k8s-master ingress]# vim mandatory.yaml 12 ……………… 13 apiVersion: apps/v1 14 kind: DaemonSet # 从Deployment改为DaemonSet 15 metadata: 16 name: nginx-ingress-controller 17 namespace: ingress-nginx 18 labels: 19 app.kubernetes.io/name: ingress-nginx 20 app.kubernetes.io/part-of: ingress-nginx 21 spec: 22 #replicas: 1 # 注释掉 23 ……………… 24 nodeSelector: 25 kubernetes.io/hostname: k8s-master # 修改处 26 # 如下几行为新加行 作用【允许在master节点运行】 27 tolerations: 28 - key: node-role.kubernetes.io/master 29 effect: NoSchedule 30 ……………… 31 ports: 32 - name: http 33 containerPort: 80 34 hostPort: 80 # 添加处【可在宿主机通过该端口访问Pod】 35 protocol: TCP 36 - name: https 37 containerPort: 443 38 hostPort: 443 # 添加处【可在宿主机通过该端口访问Pod】 39 protocol: TCP 40 ……………… 41 [root@k8s-master ingress]# 42 [root@k8s-master ingress]# kubectl apply -f mandatory.yaml 43 namespace/ingress-nginx created 44 configmap/nginx-configuration created 45 configmap/tcp-services created 46 configmap/udp-services created 47 serviceaccount/nginx-ingress-serviceaccount created 48 clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created 49 role.rbac.authorization.k8s.io/nginx-ingress-role created 50 rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created 51 clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created 52 daemonset.apps/nginx-ingress-controller created 53 limitrange/ingress-nginx created 54 [root@k8s-master ingress]# 55 [root@k8s-master ingress]# kubectl get ds -n ingress-nginx -o wide 56 NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE CONTAINERS IMAGES SELECTOR 57 nginx-ingress-controller 1 1 1 1 1 kubernetes.io/hostname=k8s-master 9m47s nginx-ingress-controller quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.30.0 app.kubernetes.io/name=ingress-nginx,app.kubernetes.io/part-of=ingress-nginx 58 [root@k8s-master ingress]# 59 [root@k8s-master ingress]# kubectl get pod -n ingress-nginx -o wide 60 NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES 61 nginx-ingress-controller-rrbh9 1/1 Running 0 9m55s 10.244.0.46 k8s-master
deply_service1的yaml信息
yaml文件
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat deply_service1.yaml 4 apiVersion: apps/v1 5 kind: Deployment 6 metadata: 7 name: myapp-deploy1 8 namespace: default 9 spec: 10 replicas: 3 11 selector: 12 matchLabels: 13 app: myapp 14 release: v1 15 template: 16 metadata: 17 labels: 18 app: myapp 19 release: v1 20 env: test 21 spec: 22 containers: 23 - name: myapp 24 image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 25 imagePullPolicy: IfNotPresent 26 ports: 27 - name: http 28 containerPort: 80 29 --- 30 apiVersion: v1 31 kind: Service 32 metadata: 33 name: myapp-clusterip1 34 namespace: default 35 spec: 36 type: ClusterIP # 默认类型 37 selector: 38 app: myapp 39 release: v1 40 ports: 41 - name: http 42 port: 80 43 targetPort: 80
启动Deployment和Service
1 [root@k8s-master ingress]# kubectl apply -f deply_service1.yaml 2 deployment.apps/myapp-deploy1 created 3 service/myapp-clusterip1 created
查看Deploy状态和信息
1 [root@k8s-master ingress]# kubectl get deploy -o wide 2 NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR 3 myapp-deploy1 3/3 3 3 28s myapp registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 app=myapp,release=v1 4 [root@k8s-master ingress]# 5 [root@k8s-master ingress]# kubectl get rs -o wide 6 NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR 7 myapp-deploy1-5695bb5658 3 3 3 30s myapp registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 app=myapp,pod-template-hash=5695bb5658,release=v1 8 [root@k8s-master ingress]# 9 [root@k8s-master ingress]# kubectl get pod -o wide --show-labels 10 NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES LABELS 11 myapp-deploy1-5695bb5658-n6548 1/1 Running 0 36s 10.244.2.144 k8s-node02app=myapp,env=test,pod-template-hash=5695bb5658,release=v1 12 myapp-deploy1-5695bb5658-rqcpb 1/1 Running 0 36s 10.244.2.143 k8s-node02 app=myapp,env=test,pod-template-hash=5695bb5658,release=v1 13 myapp-deploy1-5695bb5658-vv6gm 1/1 Running 0 36s 10.244.3.200 k8s-node01 app=myapp,env=test,pod-template-hash=5695bb5658,release=v1
curl访问pod
1 [root@k8s-master ingress]# curl 10.244.2.144 2 Hello MyApp | Version: v1 | Pod Name 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# curl 10.244.2.144/hostname.html 5 myapp-deploy1-5695bb5658-n6548 6 [root@k8s-master ingress]# 7 [root@k8s-master ingress]# curl 10.244.2.143/hostname.html 8 myapp-deploy1-5695bb5658-rqcpb 9 [root@k8s-master ingress]# 10 [root@k8s-master ingress]# curl 10.244.3.200/hostname.html 11 myapp-deploy1-5695bb5658-vv6gm
查看Service状态和信息
1 [root@k8s-master ingress]# kubectl get svc -o wide 2 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR 3 kubernetes ClusterIP 10.96.0.1443/TCP 19d 4 myapp-clusterip1 ClusterIP 10.104.146.14 80/TCP 5m38s app=myapp,release=v1
curl访问svc
1 [root@k8s-master ingress]# curl 10.104.146.14 2 Hello MyApp | Version: v1 | Pod Name 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# curl 10.104.146.14/hostname.html 5 myapp-deploy1-5695bb5658-n6548 6 [root@k8s-master ingress]# 7 [root@k8s-master ingress]# curl 10.104.146.14/hostname.html 8 myapp-deploy1-5695bb5658-vv6gm 9 [root@k8s-master ingress]# 10 [root@k8s-master ingress]# curl 10.104.146.14/hostname.html 11 myapp-deploy1-5695bb5658-rqcpb
deply_service2的yaml信息
yaml文件
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat deply_service2.yaml 4 apiVersion: apps/v1 5 kind: Deployment 6 metadata: 7 name: myapp-deploy2 8 namespace: default 9 spec: 10 replicas: 3 11 selector: 12 matchLabels: 13 app: myapp 14 release: v2 15 template: 16 metadata: 17 labels: 18 app: myapp 19 release: v2 20 env: test 21 spec: 22 containers: 23 - name: myapp 24 image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v2 25 imagePullPolicy: IfNotPresent 26 ports: 27 - name: http 28 containerPort: 80 29 --- 30 apiVersion: v1 31 kind: Service 32 metadata: 33 name: myapp-clusterip2 34 namespace: default 35 spec: 36 type: ClusterIP # 默认类型 37 selector: 38 app: myapp 39 release: v2 40 ports: 41 - name: http 42 port: 80 43 targetPort: 80
启动Deployment和Service
1 [root@k8s-master ingress]# kubectl apply -f deply_service2.yaml 2 deployment.apps/myapp-deploy2 created 3 service/myapp-clusterip2 created
查看Deploy状态和信息
1 [root@k8s-master ingress]# kubectl get deploy myapp-deploy2 -o wide 2 NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR 3 myapp-deploy2 3/3 3 3 9s myapp registry.cn-beijing.aliyuncs.com/google_registry/myapp:v2 app=myapp,release=v2 4 [root@k8s-master ingress]# 5 [root@k8s-master ingress]# kubectl get rs -o wide 6 NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR 7 myapp-deploy1-5695bb5658 3 3 3 7m23s myapp registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 app=myapp,pod-template-hash=5695bb5658,release=v1 # 之前创建的 8 myapp-deploy2-54f48f879b 3 3 3 15s myapp registry.cn-beijing.aliyuncs.com/google_registry/myapp:v2 app=myapp,pod-template-hash=54f48f879b,release=v2 # 当前deploy创建的 9 [root@k8s-master ingress]# 10 [root@k8s-master ingress]# kubectl get pod -o wide --show-labels -l "release=v2" 11 NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES LABELS 12 myapp-deploy2-54f48f879b-7pxwp 1/1 Running 0 25s 10.244.3.201 k8s-node01app=myapp,env=test,pod-template-hash=54f48f879b,release=v2 13 myapp-deploy2-54f48f879b-lqlh2 1/1 Running 0 25s 10.244.2.146 k8s-node02 app=myapp,env=test,pod-template-hash=54f48f879b,release=v2 14 myapp-deploy2-54f48f879b-pfvnn 1/1 Running 0 25s 10.244.2.145 k8s-node02 app=myapp,env=test,pod-template-hash=54f48f879b,release=v2
查看Service状态和信息
1 [root@k8s-master ingress]# kubectl get svc -o wide 2 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR 3 kubernetes ClusterIP 10.96.0.1443/TCP 19d 4 myapp-clusterip1 ClusterIP 10.104.146.14 80/TCP 8m9s app=myapp,release=v1 5 myapp-clusterip2 ClusterIP 10.110.181.62 80/TCP 61s app=myapp,release=v2
curl访问svc
1 [root@k8s-master ingress]# curl 10.110.181.62 2 Hello MyApp | Version: v2 | Pod Name 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# curl 10.110.181.62/hostname.html 5 myapp-deploy2-54f48f879b-lqlh2 6 [root@k8s-master ingress]# 7 [root@k8s-master ingress]# curl 10.110.181.62/hostname.html 8 myapp-deploy2-54f48f879b-7pxwp 9 [root@k8s-master ingress]# 10 [root@k8s-master ingress]# curl 10.110.181.62/hostname.html 11 myapp-deploy2-54f48f879b-pfvnn
Ingress HTTP代理访问
yaml文件【由于自建的service在默认default名称空间，因此这里也是default名称空间】
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat ingress-http.yaml 4 apiVersion: networking.k8s.io/v1beta1 5 kind: Ingress 6 metadata: 7 name: nginx-http 8 namespace: default 9 spec: 10 rules: 11 - host: www.zhangtest.com 12 http: 13 paths: 14 - path: / 15 backend: 16 serviceName: myapp-clusterip1 17 servicePort: 80 18 - host: blog.zhangtest.com 19 http: 20 paths: 21 - path: / 22 backend: 23 serviceName: myapp-clusterip2 24 servicePort: 80
启动ingress http并查看状态
1 [root@k8s-master ingress]# kubectl apply -f ingress-http.yaml 2 ingress.networking.k8s.io/nginx-http created 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# kubectl get ingress -o wide 5 NAME HOSTS ADDRESS PORTS AGE 6 nginx-http www.zhangtest.com,blog.zhangtest.com 80 9s
查看nginx配置文件
1 [root@k8s-master ~]# kubectl get pod -A | grep 'ingre' 2 ingress-nginx nginx-ingress-controller-rrbh9 1/1 Running 0 27m 3 [root@k8s-master ~]# 4 [root@k8s-master ~]# kubectl exec -it -n ingress-nginx nginx-ingress-controller-rrbh9 bash 5 bash-5.0$ cat /etc/nginx/nginx.conf 6 ………… 7 ##### 可见server www.zhangtest.com 和 server blog.zhangtest.com的配置
浏览器访问
hosts文件修改，添加如下信息
1 文件位置：C:\WINDOWS\System32\drivers\etc\hosts 2 添加信息如下： 3 # K8S ingress学习 4 10.0.0.110 www.zhangtest.com blog.zhangtest.com
浏览器访问www.zhangtest.com
1 http://www.zhangtest.com/ 2 http://www.zhangtest.com/hostname.html
浏览器访问blog.zhangtest.com
1 http://blog.zhangtest.com/ 2 http://blog.zhangtest.com/hostname.html
当然：除了用浏览器访问外，也可以在Linux使用curl访问。前提是修改/etc/hosts文件，对上面的两个域名进行解析。
Ingress HTTPS代理访问
SSL证书创建
1 [root@k8s-master cert]# pwd 2 /root/k8s_practice/ingress/cert 3 [root@k8s-master cert]# openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/C=CN/ST=BJ/L=BeiJing/O=BTC/OU=MOST/CN=zhang/[email protected]" 4 Generating a 2048 bit RSA private key 5 ......................................................+++ 6 ........................+++ 7 writing new private key to 'tls.key' 8 ----- 9 [root@k8s-master cert]# kubectl create secret tls tls-secret --key tls.key --cert tls.crt 10 secret/tls-secret created
创建ingress https
yaml文件【由于自建的service在默认default名称空间，因此这里也是default名称空间】
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat ingress-https.yaml 4 apiVersion: networking.k8s.io/v1beta1 5 kind: Ingress 6 metadata: 7 name: nginx-https 8 namespace: default 9 spec: 10 tls: 11 - hosts: 12 - www.zhangtest.com 13 - blog.zhangtest.com 14 secretName: tls-secret 15 rules: 16 - host: www.zhangtest.com 17 http: 18 paths: 19 - path: / 20 backend: 21 serviceName: myapp-clusterip1 22 servicePort: 80 23 - host: blog.zhangtest.com 24 http: 25 paths: 26 - path: / 27 backend: 28 serviceName: myapp-clusterip2 29 servicePort: 80
启动ingress https并查看状态
1 [root@k8s-master ingress]# kubectl apply -f ingress-https.yaml 2 ingress.networking.k8s.io/nginx-https created 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# kubectl get ingress -o wide 5 NAME HOSTS ADDRESS PORTS AGE 6 nginx-https www.zhangtest.com,blog.zhangtest.com 80, 443 8s
浏览器访问
hosts文件修改，添加如下信息
1 文件位置：C:\WINDOWS\System32\drivers\etc\hosts 2 添加信息如下： 3 # K8S ingress学习 4 10.0.0.110 www.zhangtest.com blog.zhangtest.com
浏览器访问www.zhangtest.com
1 https://www.zhangtest.com/ 2 https://www.zhangtest.com/hostname.html
浏览器访问blog.zhangtest.com
1 https://blog.zhangtest.com/ 2 https://blog.zhangtest.com/hostname.html
Ingress-Nginx实现BasicAuth认证
官网地址：
https://kubernetes.github.io/ingress-nginx/examples/auth/basic/
准备工作
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# yum install -y httpd 4 [root@k8s-master ingress]# htpasswd -c auth foo 5 New password: #输入密码 6 Re-type new password: #重复输入的密码 7 Adding password for user foo ##### 此时会生成一个 auth文件 8 [root@k8s-master ingress]# kubectl create secret generic basic-auth --from-file=auth 9 secret/basic-auth created 10 [root@k8s-master ingress]# 11 [root@k8s-master ingress]# kubectl get secret basic-auth -o yaml 12 apiVersion: v1 13 data: 14 auth: Zm9vOiRhcHIxJFpaSUJUMDZOJDVNZ3hxdkpFNWVRTi9NdnZCcVpHaC4K 15 kind: Secret 16 metadata: 17 creationTimestamp: "2020-08-17T09:42:04Z" 18 name: basic-auth 19 namespace: default 20 resourceVersion: "775573" 21 selfLink: /api/v1/namespaces/default/secrets/basic-auth 22 uid: eef0853b-a52b-4684-922a-817e4cd9e9ca 23 type: Opaque
ingress yaml文件
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat nginx_basicauth.yaml 4 apiVersion: networking.k8s.io/v1beta1 5 kind: Ingress 6 metadata: 7 name: ingress-with-auth 8 annotations: 9 # type of authentication 10 nginx.ingress.kubernetes.io/auth-type: basic 11 # name of the secret that contains the user/password definitions 12 nginx.ingress.kubernetes.io/auth-secret: basic-auth 13 # message to display with an appropriate context why the authentication is required 14 nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - foo' 15 spec: 16 rules: 17 - host: auth.zhangtest.com 18 http: 19 paths: 20 - path: / 21 backend: 22 serviceName: myapp-clusterip1 23 servicePort: 80
启动ingress并查看状态
1 [root@k8s-master ingress]# kubectl apply -f nginx_basicauth.yaml 2 ingress.networking.k8s.io/ingress-with-auth created 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# kubectl get ingress -o wide 5 NAME HOSTS ADDRESS PORTS AGE 6 ingress-with-auth auth.zhangtest.com 80 6s
浏览器访问
hosts文件修改，添加如下信息
1 文件位置：C:\WINDOWS\System32\drivers\etc\hosts 2 添加信息如下： 3 # K8S ingress学习 4 10.0.0.110 www.zhangtest.com blog.zhangtest.com auth.zhangtest.com
浏览器访问auth.zhangtest.com
http://auth.zhangtest.com/
Ingress-Nginx实现Rewrite重写
官网地址：
https://kubernetes.github.io/ingress-nginx/examples/rewrite/
重写可以使用以下注解控制：
| 名称 | 描述 | 值 |
|---|---|---|
| nginx.ingress.kubernetes.io/rewrite-target | 必须重定向的目标URL | String |
| nginx.ingress.kubernetes.io/ssl-redirect | 指示位置部分是否只能由SSL访问(当Ingress包含证书时，默认为True) | Bool |
| nginx.ingress.kubernetes.io/force-ssl-redirect | 即使Ingress没有启用TLS，也强制重定向到HTTPS | Bool |
| nginx.ingress.kubernetes.io/app-root | 定义应用程序根目录，Controller在“/”上下文中必须重定向该根目录 | String |
| nginx.ingress.kubernetes.io/use-regex | 指示Ingress上定义的路径是否使用正则表达式 | Bool |
ingress yaml文件
1 [root@k8s-master ingress]# pwd 2 /root/k8s_practice/ingress 3 [root@k8s-master ingress]# cat nginx_rewrite.yaml 4 apiVersion: networking.k8s.io/v1beta1 5 kind: Ingress 6 metadata: 7 annotations: 8 nginx.ingress.kubernetes.io/rewrite-target: https://www.baidu.com 9 name: rewrite 10 namespace: default 11 spec: 12 rules: 13 - host: rewrite.zhangtest.com 14 http: 15 paths: 16 - backend: 17 serviceName: myapp-clusterip1 18 servicePort: 80
启动ingress并查看状态
1 [root@k8s-master ingress]# kubectl apply -f nginx_rewrite.yaml 2 ingress.networking.k8s.io/rewrite created 3 [root@k8s-master ingress]# 4 [root@k8s-master ingress]# kubectl get ingress -o wide 5 NAME HOSTS ADDRESS PORTS AGE 6 rewrite rewrite.zhangtest.com 80 13s
浏览器访问
hosts文件修改，添加如下信息
1 文件位置：C:\WINDOWS\System32\drivers\etc\hosts 2 添加信息如下： 3 # K8S ingress学习 4 10.0.0.110 www.zhangtest.com blog.zhangtest.com auth.zhangtest.com rewrite.zhangtest.com
浏览器访问rewrite.zhangtest.com
http://rewrite.zhangtest.com/
之后，可见重定向到了https://www.baidu.com 百度页面