Docker容器的使用

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Docker 容器运维

容器前台运行

运行一个web应用的容器

例:运行docker容器

[root@controller ~]# docker search python

[root@controller ~]# docker pull python:3.5

[root@controller ~]# docker run -i -t python:3.5 /bin/bash

root@e7a3ceef30f2:/# python -V
Python 3.5.7
root@e7a3ceef30f2:/# exit
exit

后台运行

在下例中,给run命令加上了参数-d ,所以容器在后台运行。

参数说明:

   -d:让容器在后台运行。
   -P:将容器内部使用的网络端口映射到我们使用的主机上。

例:运行tomcat容器

[root@controller ~]# docker run --name tomcat4 -p 8080:8080 -v $PWD/test:/usr/local/tomcat/webapps/test -d tomcat


505a6b1f17649833fd78778f1e9ed684079183dda5189b11094a9be73c191182


命令说明:

-p 8080:8080:将容器的8080端口映射到主机的8080端口

-v $PWD/test:/usr/local/tomcat/webapps/test:将主机中当前目录下的test挂载到容器的/test

通过浏览器访问: http://10.0.0.20:8080/ (10.0.0.20为宿主机IP)

我们也可以通过 -p 参数来设置不一样的端口:

[root@controller ~]# docker run --name tomcat3 -p 8081:8081 -v $PWD/test:/usr/local/tomcat/webapps/test -d tomcat

使用 docker ps 来查看我们正在运行的容器:

[root@controller ~]# docker ps

CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS                              NAMES
505a6b1f1764        tomcat              "catalina.sh run"   About a minute ago   Up About a minute   8080/tcp, 0.0.0.0:8085->8085/tcp   tomcat3
db0c2ece18bc        tomcat              "catalina.sh run"   2 hours ago          Up 2 hours          0.0.0.0:8080->8080/tcp             tomcat


这里多了端口信息。

PORTS

0.0.0.0:8080->8080/tcp

查询容器

查看 WEB 应用容器

docker ps查看正在运行的容器

[root@localhost ~]# docker ps

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
5c36bf736a58        tomcat              "catalina.sh run"   17 minutes ago      Up About a minute   8080/tcp            sleepy_joliot

停止容器

[root@localhost ~]# docker stop 5c36bf736a58

5c36bf736a58

重启容器

已经停止的容器,我们可以使用命令 docker start 来启动。

[root@localhost ~]# docker start 5c36bf736a58

5c36bf736a58

docker ps -l 查询最后一次创建的容器:

docker ps -l

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                              NAMES
505a6b1f1764        tomcat              "catalina.sh run"   11 minutes ago      Up 11 minutes       8080/tcp, 0.0.0.0:8085->8085/tcp   tomcat3

正在运行的容器,我们可以使用 docker restart 命令来重启

网络端口的快捷方式

通过 docker ps 命令可以查看到容器的端口映射,docker 还提供了另一个快捷方式 docker port,使用 docker port 可以查看指定 (ID 或者名字)容器的某个确定端口映射到宿主机的端口号。

[root@localhost ~]# docker run -di --name zhuzq-httpd-test -p 9000:80 httpd

c999492803e040680230e81ed67662f185d97b3a5a8b4a2fa3a482ee090351d3

[root@localhost ~]# docker port zhuzq-httpd-test

80/tcp -> 0.0.0.0:9000

移除容器

我们可以使用 docker rm 命令来删除不需要的容器

runoob@runoob:~$ docker rm tomcat3(或id)

wizardly_chandrasekhar

删除容器时,容器必须是停止状态,否则会报如下错误

runoob@runoob:~$ docker rm tomcat3(或id)

Error response from daemon: You cannot remove a running container bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85. Stop the container before attempting removal or force remove

进入和退出容器

[root@controller ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND              CREATED                                           STATUS                     PORTS                    NAMES
ca13b27f9963        tomcat              "catalina.sh run"    3 hours ago                                       Up 3 hours                 0.0.0.0:8080->8080/tcp   tomcat4
a3662314d672        tomcat              "catalina.sh run"    5 hours ago                                       Created                                             tomcat3
e7a3ceef30f2        python:3.5          "/bin/bash"          5 hours ago                                       Exited (0) 5 hours ago                                                          hopeful_ellis

[root@controller ~]# docker start e7a3ceef30f2

e7a3ceef30f2

[root@controller ~]# docker exec -it e7a3ceef30f2 bash

在容器内部,查看它的ip地址:

root@e7a3ceef30f2:/# ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
29: eth0@if30: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever

退出容器:

root@e7a3ceef30f2:/# exit

exit


查看容器的网络信息

[root@controller ~]# docker inspect -f {{.NetworkSettings}} e7a3ceef30f2

{{ 1193683be1348677f3d05b2033eb5db3d75ba4faa703644cdb39e21c09ace206 false  0 map[] /var/run/docker/netns/1193683be134 [] []} {3fcda01386e48a956b40b09dad7450794deffc1a3dc9c91ce9b654351c8861b0 172.17.0.1  0 172.17.0.3 16  02:42:ac:11:00:03} map[bridge:0xc420152000]}

查看日志

查看 WEB 应用程序日志

docker logs [ID或者名字] 可以查看容器内部的标准输出。

[root@controller ~]# docker logs -f e7a3ceef30f2

root@e7a3ceef30f2:/# python -V
Python 3.5.7
root@e7a3ceef30f2:/# exit
exit

[root@controller ~]# docker logs -f tomcat

13-Mar-2019 08:53:15.072 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version:        Apache Tomcat/8.5.40
13-Mar-2019 08:53:15.091 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built:          Apr 10 2019 14:31:19 UTC
13-Mar-2019 08:53:15.092 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server number:         8.5.40.0
13-Mar-2019 08:53:15.092 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name:               Linux
13-Mar-2019 08:53:15.092 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version:            3.10.0-327.el7.x86_64
13-Mar-2019 08:53:15.092 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture:          amd64
13-Mar-2019 08:53:15.093 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home:             /usr/lib/jvm/java-8-openjdk-amd64/jre
13-Mar-2019 08:53:15.093 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version:           1.8.0_212-8u212-b01-1~deb9u1-b01
13-Mar-2019 08:53:15.093 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor:            Oracle Corporation

-f: 让 docker logs 像使用 tail -f 一样来输出容器内部的标准输出。

从上面,我们可以看到应用程序使用的是 5000 端口并且能够查看到应用程序的访问日志。

查看容器的进程

我们还可以使用 docker top 来查看容器内部运行的进程

[root@controller ~]# docker top tomcat(或id号)

UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
root                19518               19502               0                   16:53               ?                   00:00:29            /docker-java-home/jre/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -Dignore.endorsed.dirs= -classpath /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/tomcat -Dcatalina.home=/usr/local/tomcat -Djava.io.tmpdir=/usr/local/tomcat/temp org.apache.catalina.startup.Bootstrap start

检查 容器信息

使用 docker inspect 来查看 Docker 的底层信息。它会返回一个 JSON 文件记录着 Docker 容器的配置和状态信息。

runoob@runoob:~$ docker inspect tomcat(或id号)

[
    {
        "Id": "bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85",
        "Created": "2018-09-17T01:41:26.174228707Z",
        "Path": "python",
        "Args": [
            "app.py"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 23245,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2018-09-17T01:41:26.494185806Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
......


[root@controller ~]# docker inspect e7a3ceef30f2

[
    {
        "Id": "e7a3ceef30f2c3f9537e5d1cddc66e213306884cb07278562e321bb01c930e17",
        "Created": "2019-03-13T10:36:47.241568147Z",
        "Path": "/bin/bash",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 22245,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2019-03-13T16:01:50.83793745Z",
            "FinishedAt": "2019-03-13T10:38:05.578179041Z"
        },
        "Image": "sha256:def8e5a8701975b8b5adda9733edbb26d7f1095d424ad882909c541e4083e6ac",
        ...

容器的打包

[root@controller ~]# docker exec -it tomcat4 bash

root@ca13b27f9963:/usr/local/tomcat# java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (build 1.8.0_212-8u212-b01-1~deb9u1-b01)
OpenJDK 64-Bit Server VM (build 25.212-b01, mixed mode)
root@ca13b27f9963:/usr/local/tomcat# echo "hello world"
hello world
root@ca13b27f9963:/usr/local/tomcat# echo "i write a java program"
i write a java program
root@ca13b27f9963:/usr/local/tomcat# exit
exit

[root@controller ~]# docker export ca13b27f9963 >java_web:v1.0

容器的重命名

[root@controller ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND              CREATED             STATUS                     PORTS                    NAMES
ca13b27f9963        tomcat              "catalina.sh run"    4 hours ago         Up 4 hours                 0.0.0.0:8080->8080/tcp   tomcat4
a3662314d672        tomcat              "catalina.sh run"    6 hours ago         Created                                             tomcat3
e7a3ceef30f2        python:3.5          "/bin/bash"          6 hours ago         Up 27 minutes                                       loving_meninsky


[root@controller ~]# docker rename e7a3ceef30f2 mypython

查看容器的文件变更

[root@controller ~]# docker diff e7a3ceef30f2

C /root
A /root/.bash_history
A /1.py