Docker容器

Docker熟悉到安装到使用

本文主要是介绍Docker熟悉到安装到使用,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

Docker的安装

我安装的环境是CentOS 7 的Linux ,以下是Linux下的命令,来自官方文档。

# 1.安装所需的包

yum install -y yum-utils

# 2.设置镜像仓库
yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo #国外地址
yum-config-manager \
       --add-repo \
    http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo #阿里云

#3. 更新yum软件包索引
yum makecache fast

#4.安装docker docker-ce社区版   ee是企业版
yum install docker-ce docker-ce-cli containerd.io

#5.启动Docker
systemctl start docker

#6.验证Docker是否成功
docker version

# 7.hello-world
docker run hello-world

# 8.查看下载的hello-world镜像
docker images

卸载docker
# 1.卸载依赖
yum remove docker-ce docker-ce-cli containerd.io
# 2.删除资源
rm -rf /var/lib/docker  #docker默认工作路径
rm -rf /var/lib/containerd

阿里云镜像加速器

为了镜像速度,可以在阿里云后台配置一下镜像加速器。

1、登陆阿里云

2、阿里云后台--》弹性计算--》容器加速器--》阿里云镜像加速器

 以上红框内的指令 ,直接复制到Linux执行就得啦。

Docker原理

        Docker流程图

下图提及到DockerHub的概念,就是官方的仓库里会放着许多不同版本的镜像。只有在本机找不到的时候会从dockerHub查找,都没有就会返回错误信息了。

         底层原理

Docker是一个Client-Server结构的系统,Docker的守护进程运行在主机上,通过Socket从客户端访问。DockerServer接收到Docke-Cilent的指令,就会执行该指令。

      Docker为什么会比VM快?

1、Docker有着比虚拟机更少的抽象层,由于Docker不需要Hypervisor实现硬件资源虚拟化,运行在Docker容器上的程序直接使用的都是实际物理机的硬件资源,因此在Cpu、内存利用率上Docker将会在效率上有明显优势。

2、Docker利用的是宿主机的内核,而不需要Guest OS,因此,当新建一个容器时,Docker不需要和虚拟机一样重新加载一个操作系统,避免了引导、加载操作系统内核这个比较费时费资源的过程,当新建一个虚拟机时,虚拟机软件需要加载Guest OS,这个新建过程是分钟级别的,而Docker由于直接利用宿主机的操作系统则省略了这个过程,因此新建一个Docker容器只需要几秒                                       

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

Docker常用命令

帮助命令

帮助文档地址:https://docs.docker.com/reference/docker

docker version        #显示docker的版本信息
docker info           #显示docker的系统信息 包括镜像和容器的数量
docker 命令 --help    #万能命令   命令==例如ps run等

镜像命令

docker images 查看所有本地的主机上的镜像

[root@localhost alenwong]# docker images
REPOSITORY    TAG       IMAGE ID       CREATED        SIZE
hello-world   latest    d1165f221234   4 months ago   13.3kB

#REPOSITORY 镜像仓库源
#TAG        标识,我理解是版本的标签
#IMAGE ID   镜像ID
#CREATE     该镜像创建的时间
#SIZE       该镜像的大小

#拓展
-a, --all   #列出所有镜像
-q, --quiet #只显示出镜像的id

docker search 搜索镜像

#docker search 镜像名

#搜索mysql镜像
docker search mysql
#返回以下
NAME                              DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
mysql                             MySQL is a widely used, open-source relation…   11142     [OK]       
mariadb                           MariaDB Server is a high performing open sou…   4224      [OK]       
mysql/mysql-server                Optimized MySQL Server Docker images. Create…   829                  [OK]

#搜索收藏数大于3000的mysql
docker search mysql --filter=stars=3000
#返回以下
NAME      DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
mysql     MySQL is a widely used, open-source relation…   11142     [OK]       
mariadb   MariaDB Server is a high performing open sou…   4224      [OK]  

docker pull 下载镜像

docker pull 镜像名  不写版本下载:

[root@localhost alenwong]# docker pull mysql   #不指定版本
Using default tag: latest                      #tag latest=默认最新的版本
latest: Pulling from library/mysql
b4d181a07f80: Pull complete                    #分层下载,docker iamge的核心 联合文件系统
a462b60610f5: Pull complete 
578fafb77ab8: Pull complete 
524046006037: Pull complete 
d0cbe54c8855: Pull complete 
aa18e05cc46d: Pull complete 
32ca814c833f: Pull complete 
9ecc8abdb7f5: Pull complete 
ad042b682e0f: Pull complete 
71d327c6bb78: Pull complete 
165d1d10a3fa: Pull complete 
2f40c47d0626: Pull complete 
Digest: sha256:52b8406e4c32b8cf0557f1b74517e14c5393aff5cf0384eff62d9e81f4985d4b
Status: Downloaded newer image for mysql:latest
docker.io/library/mysql:latest                #该镜像的真实地址

#等价于:
docker pull mysql  =等=价=于=   docker pull docker.io/library/mysql:latest

docker pull 指定版本,注意: 版本号必须来自官方的DockerHub,不能乱写。 点入DockerHub搜想要d拉取的镜像。 滚下面可以看到指定几个的版本号。

 docker pull 镜像名:版本号

[root@localhost alenwong]# docker pull mysql:5.7
5.7: Pulling from library/mysql
b4d181a07f80: Already exists 
a462b60610f5: Already exists 
578fafb77ab8: Already exists 
524046006037: Already exists 
d0cbe54c8855: Already exists 
aa18e05cc46d: Already exists 
32ca814c833f: Already exists 
52645b4af634: Pull complete 
bca6a5b14385: Pull complete 
309f36297c75: Pull complete 
7d75cacde0f8: Pull complete 
Digest: sha256:1a2f9cd257e75cc80e9118b303d1648366bc2049101449bf2c8d82b022ea86b7
Status: Downloaded newer image for mysql:5.7
docker.io/library/mysql:5.7

docker rmi 删除镜像命令

#删除指定ID镜像
docker rmi -f 镜像ID

#删除多个指定ID镜像
docker rmi -f 镜像ID 镜像ID 镜像ID 镜像ID 

#递归删除镜像ID
docker fim -f $(docker images -aq)  #等于传入全部镜像ID

容器命令

我这里先下载一个CentOS套娃容器进行学习..

docker pull centos

run启动容器

docker run [可选参数] 镜像名或镜像ID?

#参数说明
--name="NAME"  容器名称如 tomcat01
-d             后台方式运行, 注意:如果碰到没有前台交互的镜像,会自动退出
-it            启用前台方式交互运行,进入容器查看内容
-p             指定容器的端口  -p 8080:8080
    -p  主机端口:容器端口  即主机端口映射到容器端口 如-p 8080:8080
    -p  容器端口 如 -p 8080
    -p  不写就随机指定端口

----------demo
#/bin/bash的意思是以这种方式的操作控制台形式进行交互(一般Linux都是这种)
[root@localhost alenwong]# docker run -it centos /bin/bash
[root@63b99200973f /]# ls
bin  dev  etc  home  lib  lib64  lost+found  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
[root@63b99200973f /]# exit
exit
[root@localhost alenwong]# ls
公共  模板  视频  图片  文档  下载  音乐  桌面
[root@localhost alenwong]# 

退出容器

exit  , 直接退出容器
Ctrl + P + Q  退出容器但不结束

列出所有运行的容器

#docer ps

空 #列出当前正在运行的容器

-a  #列出当前正在运行的容器,并带出历史内容

-n=?  #显示最近创建的内容 ?是显示的个数

-q    #只显示容器的id

#demo  下面是没有容器在运行
[root@localhost alenwong]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

#demo 下面是有容器在运行
[root@localhost alenwong]# docker run -it centos /bin/bash   
[root@2c3e7ecb2926 /]# [root@localhost alenwong]#          #这里我是Ctril + P+Q 操作
[root@localhost alenwong]# docker ps
CONTAINER ID   IMAGE     COMMAND       CREATED          STATUS          PORTS     NAMES
2c3e7ecb2926   centos    "/bin/bash"   27 seconds ago   Up 19 seconds             brave_lederberg
[root@localhost alenwong]# 


#demo 下面是查看曾经的容器记录
[root@localhost alenwong]# docker ps -a
CONTAINER ID   IMAGE         COMMAND       CREATED          STATUS                      PORTS     NAMES
2c3e7ecb2926   centos        "/bin/bash"   2 minutes ago    Exited (0) 9 seconds ago              brave_lederberg
63b99200973f   centos        "/bin/bash"   18 minutes ago   Exited (0) 17 minutes ago             elastic_curran
f1e72d6e3a34   hello-world   "/hello"      4 hours ago      Exited (0) 4 hours ago                quizzical_gagarin
7aa43808fbf8   hello-world   "/hello"      4 hours ago      Exited (0) 4 hours ago                hungry_neumann


删除容器

删除指定容器
docker rm #容器id       

#删除所有容器
docker rm -f $(docker ps -aq) 

#删除所有容器
docker ps -a -q|xargs docker rm 

启动和停止容器操作

#启动容器
docker start 容器id   
 
#重启动容器
docker restart 容器id  

#停止当前正在运行动容器
docker stop 容器id     

#强制停止当前容器
docker kill 容器id     

常用其他命令

查看日志 :docker logs 容器id

#容器要在跑,才可以看日志哦..
docker logs -f -t --tail 10  #容器id  
没有日志 # 自己编写一段shell脚本
[root@bogon /]# docker run -d centos /bin/sh -c "while true;do echo Sxr;sleep 1;done"[root@bogon /]# docker psPORTS      NAMESd5d5d925582f   centos
 
#显示日志-tf           
#显示日志 f带上时间--tail number 
#要显示的日志条数
[root@bogon /]# docker logs -f -t --tail 10 d5d5d925582f 
[root@bogon /]# docker logs -tf --tail 10 d5d5d925582f

查看容器中进程的信息:docker top 容器id

[root@bogon /]# docker top 容器idUID                 

PID                 PPID                C                   STIME               TTY                 TIME     root                3064                3044                0                   09:37               ?                   00:00:00 root                3117                3064                0                   09:38               ?                   00:00:00

查看容器进程的信息: docker inspect 容器ID

[root@localhost alenwong]# docker inspect 436b9a7bc8cd
[
    {
        "Id": "436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009",
        "Created": "2021-07-20T13:57:06.359593394Z",
        "Path": "/hello",
        "Args": [],
        "State": {
            "Status": "exited",
            "Running": false,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 0,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2021-07-20T13:57:10.951556968Z",
            "FinishedAt": "2021-07-20T13:57:10.912682656Z"
        },
        "Image": "sha256:d1165f2212346b2bab48cb01c1e39ee8ad1be46b87873d9ca7a4e434980a7726",
        "ResolvConfPath": "/var/lib/docker/containers/436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009/hostname",
        "HostsPath": "/var/lib/docker/containers/436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009/hosts",
        "LogPath": "/var/lib/docker/containers/436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009/436b9a7bc8cd291d3f138cab1803dab00bc668eb77fba8476f08c90aae54d009-json.log",
        "Name": "/exciting_williamson",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {},
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "CgroupnsMode": "host",
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "private",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DeviceRequests": null,
            "KernelMemory": 0,
            "KernelMemoryTCP": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": null,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/asound",
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/02df75b141067ac7ea2f22c494597397058416f08f3ff7e87192cbb7661acea6-init/diff:/var/lib/docker/overlay2/14a05bbb4b6427579b96a7f525fad5517a16042681814b0b96fa3652e09566e3/diff",
                "MergedDir": "/var/lib/docker/overlay2/02df75b141067ac7ea2f22c494597397058416f08f3ff7e87192cbb7661acea6/merged",
                "UpperDir": "/var/lib/docker/overlay2/02df75b141067ac7ea2f22c494597397058416f08f3ff7e87192cbb7661acea6/diff",
                "WorkDir": "/var/lib/docker/overlay2/02df75b141067ac7ea2f22c494597397058416f08f3ff7e87192cbb7661acea6/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [],
        "Config": {
            "Hostname": "436b9a7bc8cd",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": true,
            "AttachStderr": true,
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
            ],
            "Cmd": [
                "/hello"
            ],
            "Image": "hello-world",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": null,
            "OnBuild": null,
            "Labels": {}
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "8d42c55dd527d0fa98c0dd7d43ef7c22b27f1e33766475d526c504a2ee6efd05",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {},
            "SandboxKey": "/var/run/docker/netns/8d42c55dd527",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "",
            "Gateway": "",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "",
            "IPPrefixLen": 0,
            "IPv6Gateway": "",
            "MacAddress": "",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "24edc026dabc9d6bccf4d8e11220ac8bf1303be9916b1e913e38e6e802121623",
                    "EndpointID": "",
                    "Gateway": "",
                    "IPAddress": "",
                    "IPPrefixLen": 0,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "",
                    "DriverOpts": null
                }
            }
        }
    }
]

进入容器命令 docker exec和docker attach

注意: exec是进入容器并且新开一个终端; attach是进入一个正在运行的容器,不会新开一个终端窗口。

#docker exec 容器ID
[root@localhost alenwong]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                 NAMES
dcdf651611cd   mysql:5.7   "docker-entrypoint.s…"   18 minutes ago   Up 18 minutes   3306/tcp, 33060/tcp   mysql_01
8d9ae72043d9   centos      "/bin/bash"              45 minutes ago   Up 45 minutes                         condescending_murdock
[root@localhost alenwong]# docker exec -it mysql:5.7 /bin/bash
Error: No such container: mysql:5.7
[root@localhost alenwong]# clear
[root@localhost alenwong]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                 NAMES
dcdf651611cd   mysql:5.7   "docker-entrypoint.s…"   19 minutes ago   Up 19 minutes   3306/tcp, 33060/tcp   mysql_01
8d9ae72043d9   centos      "/bin/bash"              46 minutes ago   Up 46 minutes                         condescending_murdock
[root@localhost alenwong]# docker exec -it dcdf651611cd /bin/bash
root@dcdf651611cd:/# mysql -uroot -p


#docker attach ---------->直接进入容器,不新开窗口.
[root@localhost alenwong]# docker attach dcdf651611cd

Docker从容器内拷贝文件到目标主机上

docker cp 容器id:容器路径 目标主机路径

docker cp 容器id:容器内路径 目的的主机路径
[root@bogon /home]# docker cp 容器id:/容器路径 /主机路径

#测试
[root@localhost alenwong]# pwd   先看看目前路径
/home/alenwong
[root@localhost alenwong]# pwd
/home/alenwong
[root@localhost alenwong]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                 NAMES
dcdf651611cd   mysql:5.7   "docker-entrypoint.s…"   29 minutes ago   Up 29 minutes   3306/tcp, 33060/tcp   mysql_01
[root@localhost alenwong]# docker run -it centos /bin/bash  #进入Centos容器创建文件
[root@c1e7eef34a80 /]# ls
bin  etc   lib    lost+found  mnt  proc  run   srv  tmp  var
dev  home  lib64  media       opt  root  sbin  sys  usr
[root@c1e7eef34a80 /]# cd home
[root@c1e7eef34a80 home]# ll
bash: ll: command not found
[root@c1e7eef34a80 home]# ls       #该路径下没有东西
[root@c1e7eef34a80 home]# pwd
/home
[root@c1e7eef34a80 home]# mkdir text.txt     #创建一个文件
[root@c1e7eef34a80 home]# ls
text.txt
[root@c1e7eef34a80 home]# exit
exit
[root@localhost alenwong]# docker ps -a  #看看历史容器ID
CONTAINER ID   IMAGE          COMMAND                  CREATED             STATUS                            PORTS                 NAMES
c1e7eef34a80   centos         "/bin/bash"              57 seconds ago      Exited (0) 17 seconds ago                               modest_brattain
b50a426ffcf0   mysql:5.7      "docker-entrypoint.s…"   30 minutes ago      Exited (1) 29 minutes ago                               reverent_cannon
#关键是一以下的命令..........docker cp 容器id:路径  目标路径
[root@localhost alenwong]# docker cp c1e7eef34a80:/home/text.txt /home/alenwong
[root@localhost alenwong]# ls
text.txt  公共  模板  视频  图片  文档  下载  音乐  桌面  #多了个text.txt了吧

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