Pod初始化容器之Init Container

Init 容器的介绍

Pod能够具有多个容器，应用运行在容器里面，但是它也可能有一个或多个先于应用容器启动的 Init容器
Init 容器与普通的容器非常像，除了如下两点：
c Init 容器总是运行到成功完成为止
2）每个 Init 容器都必须在下一个 Init 容器启动之前成功完成
如果 Pod 的 Init 容器失败， Kubernetes 会不断地重启该 Pod ，直到 Init 容器成功为止。然而，如果 Pod 对应的 restartPolicy 为 Never。
Init 容器的作用

因为 Init 容器具有与应用程序容器分离的单独镜像，所以它们的启动相关代码具有如下优势：
1）它们可以包含并运行实用工具，但是出于安全考虑，是不建议在应用程序容器镜像中包含这些实用工具的
2) 它们可以包含使用工具和定制化代码来安装，但是不能出现在应用程序镜像中。例如，创建镜像没必要 FROM 另一个镜像，只需要在安装过程中使用类似 sed 、 awk 、 python 或 dig
这样的工具。
3) 应用程序镜像可以分离出创建和部署的角色，而没有必要联合它们构建一个单独的镜像。
4) Init 容器使用 Linux Namespace ，所以相对应用程序容器来说具有不同的文件系统视图。因此，它们能够具有访问 Secret 的权限，而应用程序容器则不能。
5) 它们必须在应用程序容器启动之前运行完成，而应用程序容器是并行运行的，所以 Init 容器能够提供了一种简单的阻塞或延迟应用容器的启动的方法，直到满足了一组先决条件。

测试

说明：主要是在启动Pod,有2个initc，一开始是没有准备的，所以现象会显示初始化0/2

init.yaml

kind: Pod

metadata:

  name: myapp-pod

  labels:

    app: myapp

spec:

  containers:

  - name: myapp-container

    image: busybox

    command: ['sh', '-c', 'echo The app is running! && sleep 3600']

  initContainers:

  - name: init-myservice

    image: busybox

    command: ['sh', '-c', 'until nslookup myservice; do echo waiting for myservice; sleep 2; done;']

  - name: init-mydb

    image: busybox

    command: ['sh', '-c', 'until nslookup mydb; do echo waiting for mydb; sleep 2; done;']

[root@k8s-master mnt]# kubectl create -f init.yaml

pod/myapp-pod created

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          8s

[root@k8s-master mnt]# kubectl describe myapp-pod

error: the server doesn't have a resource type "myapp-pod"

[root@k8s-master mnt]# kubectl describe pod myapp-pod

Name:         myapp-pod

Namespace:    default

Priority:     0

Node:         k8s-node02/192.168.180.134

Start Time:   Wed, 18 Dec 2019 22:02:57 +0800

Labels:       app=myapp

Annotations:  <none>

Status:       Pending

IP:           10.244.1.9

IPs:

  IP:  10.244.1.9

Init Containers:

  init-myservice:

    Container ID:  docker://3c0e850042efab506f95737adfd3dc6ef2da9218ce51eb5eb4e94573a657fd2b

    Image:         busybox

    Image ID:      docker-pullable://busybox@sha256:1828edd60c5efd34b2bf5dd3282ec0cc04d47b2ff9caa0b6d4f07a21d1c08084

    Port:          <none>

    Host Port:     <none>

    Command:

      sh

      -c

      until nslookup myservice; do echo waiting for myservice; sleep 2; done;

    State:          Running

      Started:      Wed, 18 Dec 2019 22:03:03 +0800

    Ready:          False

    Restart Count:  0

    Environment:    <none>

    Mounts:

      /var/run/secrets/kubernetes.io/serviceaccount from default-token-gx2h8 (ro)

  init-mydb:

    Container ID:

    Image:         busybox

    Image ID:

    Port:          <none>

    Host Port:     <none>

    Command:

      sh

      -c

      until nslookup mydb; do echo waiting for mydb; sleep 2; done;

    State:          Waiting

      Reason:       PodInitializing

    Ready:          False

    Restart Count:  0

    Environment:    <none>

    Mounts:

      /var/run/secrets/kubernetes.io/serviceaccount from default-token-gx2h8 (ro)

Containers:

  myapp-container:

    Container ID:

    Image:         busybox

    Image ID:

    Port:          <none>

    Host Port:     <none>

    Command:

      sh

      -c

      echo The app is running! && sleep 3600

    State:          Waiting

      Reason:       PodInitializing

    Ready:          False

    Restart Count:  0

    Environment:    <none>

    Mounts:

      /var/run/secrets/kubernetes.io/serviceaccount from default-token-gx2h8 (ro)

Conditions:

  Type              Status

  Initialized       False

  Ready             False

  ContainersReady   False

  PodScheduled      True

Volumes:

  default-token-gx2h8:

    Type:        Secret (a volume populated by a Secret)

    SecretName:  default-token-gx2h8

    Optional:    false

QoS Class:       BestEffort

Node-Selectors:  <none>

Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s

                 node.kubernetes.io/unreachable:NoExecute for 300s

Events:

  Type    Reason     Age        From                 Message

  ----    ------     ----       ----                 -------

  Normal  Scheduled  <unknown>  default-scheduler    Successfully assigned default/myapp-pod to k8s-node02

  Normal  Pulling    22s        kubelet, k8s-node02  Pulling image "busybox"

  Normal  Pulled     18s        kubelet, k8s-node02  Successfully pulled image "busybox"

  Normal  Created    18s        kubelet, k8s-node02  Created container init-myservice

  Normal  Started    17s        kubelet, k8s-node02  Started container init-myservice

查看myservice

[root@k8s-master mnt]# kubectl logs myapp-pod -c init-myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

Server:         10.96.0.10

Address:        10.96.0.10:53

** server can't find myservice.default.svc.cluster.local: NXDOMAIN

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

*** Can't find myservice.default.svc.cluster.local: No answer

*** Can't find myservice.svc.cluster.local: No answer

*** Can't find myservice.cluster.local: No answer

*** Can't find myservice.localdomain: No answer

waiting for myservice

myservice.yaml

[root@k8s-master mnt]# cat myservice.yaml

kind: Service

apiVersion: v1

metadata:

  name: myservice

spec:

  ports:

    - protocol: TCP

      port: 80

      targetPort: 9376

[root@k8s-master mnt]#

[root@k8s-master mnt]# vim myservice.yaml

[root@k8s-master mnt]# kubectl create -f myservice.yaml

service/myservice created

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m23s

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m25s

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m27s

[root@k8s-master mnt]# kubectl get svc

NAME         TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)   AGE

kubernetes   ClusterIP   10.96.0.1     <none>        443/TCP   10h

myservice    ClusterIP   10.102.35.5   <none>        80/TCP    49s

[root@k8s-master mnt]# kubectl get pod -n kube-system

NAME                                 READY   STATUS    RESTARTS   AGE

coredns-58cc8c89f4-pzbrd             1/1     Running   23         10h

coredns-58cc8c89f4-vmhl2             1/1     Running   23         10h

etcd-k8s-master                      1/1     Running   4          10h

kube-apiserver-k8s-master            1/1     Running   4          10h

kube-controller-manager-k8s-master   1/1     Running   21         10h

kube-flannel-ds-amd64-c4fs4          1/1     Running   2          9h

kube-flannel-ds-amd64-ct6mc          1/1     Running   2          9h

kube-flannel-ds-amd64-mtzz9          1/1     Running   5          9h

kube-proxy-9bdql                     1/1     Running   2          9h

kube-proxy-cv8lk                     1/1     Running   2          9h

kube-proxy-h8jk8                     1/1     Running   4          10h

kube-scheduler-k8s-master            1/1     Running   21         10h

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:1/2   0          5m58s

[root@k8s-master mnt]# vim myservice.yaml

[root@k8s-master mnt]# kubectl create -f myservice.yaml

service/myservice created

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m23s

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m25s

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:0/2   0          4m27s

[root@k8s-master mnt]# kubectl get svc

NAME         TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)   AGE

kubernetes   ClusterIP   10.96.0.1     <none>        443/TCP   10h

myservice    ClusterIP   10.102.35.5   <none>        80/TCP    49s

[root@k8s-master mnt]# kubectl get pod -n kube-system

NAME                                 READY   STATUS    RESTARTS   AGE

coredns-58cc8c89f4-pzbrd             1/1     Running   23         10h

coredns-58cc8c89f4-vmhl2             1/1     Running   23         10h

etcd-k8s-master                      1/1     Running   4          10h

kube-apiserver-k8s-master            1/1     Running   4          10h

kube-controller-manager-k8s-master   1/1     Running   21         10h

kube-flannel-ds-amd64-c4fs4          1/1     Running   2          9h

kube-flannel-ds-amd64-ct6mc          1/1     Running   2          9h

kube-flannel-ds-amd64-mtzz9          1/1     Running   5          9h

kube-proxy-9bdql                     1/1     Running   2          9h

kube-proxy-cv8lk                     1/1     Running   2          9h

kube-proxy-h8jk8                     1/1     Running   4          10h

kube-scheduler-k8s-master            1/1     Running   21         10h

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:1/2   0          5m58s

现象：发现变成1/2了

[root@k8s-master mnt]# cat mydb.yaml

kind: Service

apiVersion: v1

metadata:

  name: mydb

spec:

  ports:

    - protocol: TCP

      port: 80

      targetPort: 9377

[root@k8s-master mnt]#

[root@k8s-master mnt]# vim mydb.yaml

[root@k8s-master mnt]# kubectl create -f mydb.yaml

service/mydb created

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:1/2   0          11m

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS     RESTARTS   AGE

myapp-pod   0/1     Init:1/2   0          11m

[root@k8s-master mnt]# kubectl get pod

NAME        READY   STATUS    RESTARTS   AGE

myapp-pod   1/1     Running   0          12m

[root@k8s-master mnt]# kubectl get svc

NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE

kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   10h

mydb         ClusterIP   10.104.158.92   <none>        80/TCP    3m24s

myservice    ClusterIP   10.102.35.5     <none>        80/TCP    10m

[root@k8s-master mnt]#

现象：myapp-pod起来了

说明

在 Pod 启动过程中， Init 容器会按顺序在网络和数据卷初始化之后启动。每个容器必须在下一个容器启动之前成功退出
如果由于运行时或失败退出，将导致容器启动失败，它会根据 Pod 的 restartPolicy 指定的策略进行重试。然而，如果 Pod 的 restartPolicy 设置为 Always ， Init 容器失败时会使用RestartPolicy 策略
在所有的 Init 容器没有成功之前， Pod 将不会变成 Ready 状态。 Init 容器的端口将不会在Service 中进行聚集。正在初始化中的 Pod 处于 Pending 状态，但应该会将 Initializing 状态设置为 true
如果 Pod 重启，所有 Init 容器必须重新执行
对 Init 容器 spec 的修改被限制在容器 image 字段，修改其他字段都不会生效。更改 Init容器的 image 字段，等价于重启该 Pod
Init 容器具有应用容器的所有字段。除了 readinessProbe ，因为 Init 容器无法定义不同于完成（ completion ）的就绪（ readiness ）之外的其他状态。这会在验证过程中强制
在 Pod 中的每个 app 和 Init 容器的名称必须唯一；与任何其它容器共享同一个名称，会在验证时抛出错误

Pod初始化容器之Init Container的更多相关文章

k8s中初始化容器（init container）的作用及其使用方法
概述在容器的部署过程中,有的时候需要在容器运行之前进行一些预配置的工作,比如下载配置,判断某些服务是否启动,修改配置等一些准备的工作,想要实现这些功能,在k8s中可以使用初始化容器,在应用容器运行之 ...
Init Container（初始化容器）
在很多应用场景中,应用在启动之前都需要进行如下初始化操作. ◎ 等待其他关联组件正确运行(例如数据库或某个后台服务). ◎ 基于环境变量或配置模板生成配置文件. ◎ 从远程数据库获取本地所需配置,或者 ...
Kubernetes init container
目录简介配置 init container与应用容器的区别简介在很多应用场景中,应用在启动之前都需要进行如下初始化操作: 等待其他关联组件正确运行(例如数据库或某个后台服务) 基于环境变量或配 ...
kubernetes之初始容器(init container)
系列目录理解初始容器一个pod里可以运行多个容器,它也可以运行一个或者多个初始容器,初始容器先于应用容器运行,除了以下两点外,初始容器和普通容器没有什么两样: 它们总是run to complet ...
init container
init container与应用容器在本质上是一样的, 但它们是仅运行一次就结束的任务, 并且必须在成功执行完成后, 系统才能继续执行下一个容器, 可以用在例如应用容器启动前做一些初始化工作,当in ...
Java并发编程：并发容器之CopyOnWriteArrayList（转载）
Java并发编程:并发容器之CopyOnWriteArrayList(转载) 原文链接: http://ifeve.com/java-copy-on-write/ Copy-On-Write简称COW ...
Java并发编程：并发容器之ConcurrentHashMap（转载）
Java并发编程:并发容器之ConcurrentHashMap(转载) 下面这部分内容转载自: http://www.haogongju.net/art/2350374 JDK5中添加了新的concu ...
Java并发编程：并发容器之ConcurrentHashMap
转载: Java并发编程:并发容器之ConcurrentHashMap JDK5中添加了新的concurrent包,相对同步容器而言,并发容器通过一些机制改进了并发性能.因为同步容器将所有对容器状态的 ...
Java并发编程：并发容器之CopyOnWriteArrayList
转载: Java并发编程:并发容器之CopyOnWriteArrayList Copy-On-Write简称COW,是一种用于程序设计中的优化策略.其基本思路是,从一开始大家都在共享同一个内容,当某个 ...

随机推荐

Storm本地启动拓扑报错：Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/storm/topology/IRichSpout
问题描述: Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/storm/topology ...
Docker 镜像与容器管理
镜像与容器简介 Docker的大部分操作都围绕着它的三大核心概念:镜像.容器.仓库而展开.因此,准确把握这三大核心概念对于掌握Docker技术尤为重要,在docker中,我们重点关注的就是镜像和容器了 ...
使用openresty实现按照流量百分比控制的灰度分流控制
安装好以后直接就可以配置实践了,openresty将lua都集成好了,nginx配置文件无需特殊声明引入lua file. 1.nginx.conf 添加两个灰度发布的环境 #grey 灰度环境地址 ...
计算机网络--TCP三次握手和四次挥手
TCP(传输控制协议) TCP(Transmission Control Protocol 传输控制协议)是一种面向连接的.可靠的.基于字节流的传输层通信协议.通过三次握手建立连接,通讯完成时要拆除连 ...
关于redis的几件小事(九)redis的并发竞争问题
1.什么是并发竞争就是多客户端同时并发写一个key,可能本来应该先到的数据后到了,导致数据版本错了.或者是多客户端同时获取一个key,修改值之后再写回去,只要顺序错了,数据就错了. 2.怎么解决采 ...
docker toolbox的redis 配置主从及哨兵模式保证高可用
redis 的缓存中间件安装方法,简单举例如下: 环境: docker toolbox 一主从模式1 搜索redis镜像 docker search redis2 拉取镜像docker pul ...
05 Python网络爬虫的数据解析方式
一.爬虫数据解析的流程 1.指定url 2.基于requests模块发起请求 3.获取响应中的数据 4.数据解析 5.进行持久化存储二.解析方法 (1)正则解析 (2)bs4解析 (3)xpath解 ...
大神的JS代码风格指南
js代码风格指南:1.缩进使用空格,不要用制表符2.必须用分号3.暂时不用ES6(modules)例如export和import命令4.不鼓励(不禁止)水平对齐5.少用var 都应该使用const或者 ...
第十三篇 JS 操作table表格
JS 操作table表格这节课难度可能高一点,因为没有提前解释if判断.for循环.这节课是直接把这两样用上了,老师先简单介绍一下: if,判断语句,判断就很简单了嘛,假如说1=1(1等于1),当然 ...
模块之time与datetime
模块之time与datetime import time print (time.clock()) print(time.process_time()) #测量处理器运算时间 print(time.a ...

Pod初始化容器之Init Container

Pod初始化容器之Init Container的更多相关文章

随机推荐

热门专题