目录
- 一、认识docer
- 二、在阿里云服务器上配置Docker
- 三、底层原理
- 4、常用命令
- （1）Docker中常见镜像命令
- （2）Docker中常见容器命令
- （3）日志查看命令
- （4）进入容器的命令与拷贝命令
一、认识docer
传统虚拟机方式
拥有完整内核和相应的库才能安装需要的app，模拟了一台完整的电脑
缺点：
- 资源占用多
- 冗余步骤多
- 启动慢
- 资源公用，某个设置出问题可能导致多个应用出问题
docer容器化技术
优点：
- 容器内的应用直接运行在宿主机的内核，容器没有自己的内核
- 每个容器内有一个属于自己的文件系统互不影响，容器之间相互隔离互不影响
- 打包镜像发布测试，一键运行
- 更便捷的升级和扩容
- 容器化之后，开发和测试环境高度一致
- 更高效的计算资源利用，Docer是内核级别的虚拟化，可以在一个物理机上运行多个容器实例，服务器性能可以压榨到极致
镜像（image）容器（container）仓库（repository）
流程：客户端启动docer里的一个容器，容器要从服务器上下载
二、在阿里云服务器上配置Docker
需要购买一个阿里云服务器，活动99一年的就够了，需要分配外网ipv4地址
步骤（参考docker官网文档）
1、卸载旧的docker
sudo yum remove docker \docker-client \docker-client-latest \docker-common \docker-latest \docker-latest-logrotate\docker-logrotate \docker-engine
2、添加仓库
sudo yum install -y yum-utils
3、设置镜像仓库为阿里云国内源
sudo yum-config-manager --add-repo \
http://mirrors.aliyun.com/dockerce/linux/centos/docker-ce.repo
4、更新索引
yum makecache fast
5、安装docker
sudo yum install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
6、启动docker
sudo systemctl start docker
7、判断是否启动成功
docker version
sudo docker run hello-world
hello-word程序的执行流程
8、配置阿里云镜像加速
sudo mkdir -p /etc/dockersudo tee /etc/docker/daemon.json <<-'EOF'
{"registry-mirrors": ["https://rpu0hzw5.mirror.aliyuncs.com"]
}
EOFEOsudo systemctl daemon-reload sudo systemctl restart docker
三、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接受到Docker-Client的指令，就会执行这个命令
Docker为什么比VM快
- Docker有着比虚拟机更少的抽象层
- Docker利用的是宿主机的内核,vm需要的是Guest OS（Guest Operating System 指在虚拟化环境中运行的操作系统）
所以，新建一个容器的时候，docker不需要和虚拟机一样重新加载一个操作系统的内核，直接利用宿主机的操作系统内核
4、常用命令
（1）Docker中常见镜像命令
查看帮助文档 docker [命令] --help
[root@aliyun_docker ~]# docker top --helpUsage: docker top CONTAINER [ps OPTIONS]Display the running processes of a containerAliases:docker container top, docker top
搜索镜像
docker search
[root@iZ2vc3j8qdus28heb8myw2Z ~]# docker search mysql
NAME DESCRIPTION STARS OFFICIAL
mysql MySQL is a widely used, open-source relation… 15008 [OK]
mariadb MariaDB Server is a high performing open sou… 5722 [OK]下载镜像
docker pull
[root@iZ2vc3j8qdus28heb8myw2Z ~]# docker pull mysql
Using default tag: latest#如果不写tag默认下载最新版本
latest: Pulling from library/mysql
72a69066d2fe: Pull complete
93619dbc5b36: Pull complete
99da31dd6142: Pull complete
626033c43d70: Pull complete
37d5d7efb64e: Pull complete
ac563158d721: Pull complete
d2ba16033dad: Pull complete
688ba7d5c01a: Pull complete
00e060b6d11d: Pull complete
1c04857f594f: Pull complete
4d7cfa90e6ea: Pull complete
e0431212d27d: Pull complete
Digest: sha256:e9027fe4d91c0153429607251656806cc784e914937271037f7738bd5b8e7709
Status: Downloaded newer image for mysql:latest
docker.io/library/mysql:latest当下载同应用不同版本只会下载没有的部分，原有的可以公用的部分不会重复下载，节省空间
[root@iZ2vc3j8qdus28heb8myw2Z ~]# docker pull mysql:5.7
5.7: Pulling from library/mysql
72a69066d2fe: Already exists
93619dbc5b36: Already exists
99da31dd6142: Already exists
626033c43d70: Already exists
37d5d7efb64e: Already exists
ac563158d721: Already exists
d2ba16033dad: Already exists
0ceb82207cd7: Pull complete
37f2405cae96: Pull complete
e2482e017e53: Pull complete
70deed891d42: Pull complete
Digest: sha256:f2ad209efe9c67104167fc609cca6973c8422939491c9345270175a300419f94
Status: Downloaded newer image for mysql:5.7
docker.io/library/mysql:5.7
查看所有镜像
docker images
[root@iZ2vc3j8qdus28heb8myw2Z ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest d2c94e258dcb 11 months ago 13.3kB
mysql 5.7 c20987f18b13 2 years ago 448MB
mysql latest 3218b38490ce 2 years ago 516MB
通过IMAGE ID 删除 image，加空格可以删除多个，
dock rmi -f $(docker images -aq)组合命令删除全部容器
[root@iZ2vc3j8qdus28heb8myw2Z ~]# docker rmi -f 3218b38490ce
Untagged: mysql:latest
Untagged: mysql@sha256:e9027fe4d91c0153429607251656806cc784e914937271037f7738bd5b8e7709
Deleted: sha256:3218b38490cec8d31976a40b92e09d61377359eab878db49f025e5d464367f3b
Deleted: sha256:aa81ca46575069829fe1b3c654d9e8feb43b4373932159fe2cad1ac13524a2f5
Deleted: sha256:0558823b9fbe967ea6d7174999be3cc9250b3423036370dc1a6888168cbd224d
Deleted: sha256:a46013db1d31231a0e1bac7eeda5ad4786dea0b1773927b45f92ea352a6d7ff9
Deleted: sha256:af161a47bb22852e9e3caf39f1dcd590b64bb8fae54315f9c2e7dc35b025e4e3
Deleted: sha256:feff1495e6982a7e91edc59b96ea74fd80e03674d92c7ec8a502b417268822ff
[root@iZ2vc3j8qdus28heb8myw2Z ~]#
（2）Docker中常见容器命令
有了镜像才可以创建容器，
新建容器并启动
docker run [可选参数] image
#可选参数说明
–name = “Name” 容器名字,用来区分容器 tomcat01 tomcat02，用来区分容器
-d 后台方式运行（如果要后台运行必须要有一个前台进程，容器启动后发现自己没有提供服务就会立刻停止）
-it 使用交互方式运行，进入容器查看内容
-p 指定容器的端口 -P 8080:8080
-p ip:主机端口:容器端口
-p 主机端口:容落端口 (常用)
-p 容器端口
容器端口
-p 随机指定端口
[root@aliyun_docker ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest d2c94e258dcb 11 months ago 13.3kB
mysql 5.7 c20987f18b13 2 years ago 448MB
centos latest 5d0da3dc9764 2 years ago 231MB
[root@aliyun_docker ~]# docker run -it centos /bin/bash
[root@a790c5209310 /]# 可以发现进入容器后主机名称变了
退出（按三个键CTRL+p+q，退出不关闭）
[root@aliyun_docker ~]# docker run -it centos /bin/bash
[root@b8630535a0c9 /]# [root@aliyun_docker ~]#
[root@aliyun_docker ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b8630535a0c9 centos "/bin/bash" 43 seconds ago Up 43 seconds keen_kepler
[root@b8630535a0c9 /]# exit
查看当前正在运行/运行过的容器（加 -a）
[root@aliyun_docker ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@aliyun_docker ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a790c5209310 centos "/bin/bash" 3 minutes ago Exited (0) About a minute ago funny_brahmagupta
2321a478186b hello-world "/hello" 4 hours ago Exited (0) 4 hours ago eager_pascal
[root@aliyun_docker ~]#
只显示编号 -q
[root@aliyun_docker ~]# docker ps -aq
a790c5209310
2321a478186b删除容器
docker rm 容器id #删除指定容器正在运行的不能删除（加-f）
docker rm -f $(docker ps -aq) #删除所有
docker ps -a -q|xargs docker rm #通过管道删除
[root@aliyun_docker ~]# docker rm b8630535a0c9
Error response from daemon: cannot remove container "/keen_kepler": container is running: stop the container before removing or force remove
启动和停止
docker start 容器id #启动容器
docker restart 容器id #重启容器
docker stop 容器id #停止当前正在运行的容器
docker kill 容器id #强制停止当前容器（实例仍然存在）
（3）日志查看命令
写一段shell脚本
[root@aliyun_docker ~]# docker run -d centos /bin/bash -c "while true;do echo xiakucao;sleep 1;done"
22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf
[root@aliyun_docker ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
22249409fb3c centos "/bin/bash -c 'while…" 5 seconds ago Up 3 seconds jolly_hodgkin
b8630535a0c9 centos "/bin/bash" 29 minutes ago Up 29 minutes keen_kepler
[root@aliyun_docker ~]#
显示指定行数的日志
[root@aliyun_docker ~]# docker logs -f -t --tail 10 22249409fb3c
2024-04-18T14:15:44.419231635Z xiakucao
2024-04-18T14:15:45.421276341Z xiakucao
2024-04-18T14:15:46.423269443Z xiakucao
2024-04-18T14:15:47.425443716Z xiakucao
2024-04-18T14:15:48.427495542Z xiakucao
2024-04-18T14:15:49.429472406Z xiakucao
2024-04-18T14:15:50.431600097Z xiakucao
2024-04-18T14:15:51.434124367Z xiakucao
2024-04-18T14:15:52.436540492Z xiakucao
2024-04-18T14:15:53.438632432Z xiakucao
2024-04-18T14:15:54.441042791Z xiakucao
2024-04-18T14:15:55.443170520Z xiakucao
2024-04-18T14:15:56.445296720Z xiakucao
2024-04-18T14:15:57.447415752Z xiakucao
2024-04-18T14:15:58.449874664Z xiakucao
2024-04-18T14:15:59.451981852Z xiakucao
^Z
[3]+ Stopped docker logs -f -t --tail 10 22249409fb3c
[root@aliyun_docker ~]#
查看容器中进程信息
[root@aliyun_docker ~]# docker top 22249409fb3c
UID PID PPID C STIME TTY TIME CMD
root 1769 1748 0 22:14 ? 00:00:00 /bin/bash -c while true;do echo xiakucao;sleep 1;done
root 2122 1769 0 22:19 ? 00:00:00 /usr/bin/coreutils --coreutils-prog-shebang=sleep /usr/bin/sleep 1
查看镜像的元数据
docker inspect
可以看到IMAGE ID截取的是部分ID
[root@aliyun_docker ~]# docker inspect 22249409fb3c
[{"Id": "22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf","Created": "2024-04-18T14:14:13.991971662Z","Path": "/bin/bash","Args": ["-c","while true;do echo xiakucao;sleep 1;done"],"State": {"Status": "running","Running": true,"Paused": false,"Restarting": false,"OOMKilled": false,"Dead": false,"Pid": 1769,"ExitCode": 0,"Error": "","StartedAt": "2024-04-18T14:14:14.22346875Z","FinishedAt": "0001-01-01T00:00:00Z"},"Image": "sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6","ResolvConfPath": "/var/lib/docker/containers/22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf/resolv.conf","HostnamePath": "/var/lib/docker/containers/22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf/hostname","HostsPath": "/var/lib/docker/containers/22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf/hosts","LogPath": "/var/lib/docker/containers/22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf/22249409fb3c95efe4ad51637a6340abb5b5c212183531a4ee261444aef130cf-json.log","Name": "/jolly_hodgkin","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,"ConsoleSize": [31,102],"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","Isolation": "","CpuShares": 0,"Memory": 0,"NanoCpus": 0,"CgroupParent": "","BlkioWeight": 0,"BlkioWeightDevice": [],"BlkioDeviceReadBps": [],"BlkioDeviceWriteBps": [],"BlkioDeviceReadIOps": [],"BlkioDeviceWriteIOps": [],"CpuPeriod": 0,"CpuQuota": 0,"CpuRealtimePeriod": 0,"CpuRealtimeRuntime": 0,"CpusetCpus": "","CpusetMems": "","Devices": [],"DeviceCgroupRules": null,"DeviceRequests": null,"MemoryReservation": 0,"MemorySwap": 0,"MemorySwappiness": null,"OomKillDisable": false,"PidsLimit": null,"Ulimits": [],"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","/sys/devices/virtual/powercap"],"ReadonlyPaths": ["/proc/bus","/proc/fs","/proc/irq","/proc/sys","/proc/sysrq-trigger"]},"GraphDriver": {"Data": {"LowerDir": "/var/lib/docker/overlay2/46c4ebdbc616cb8d052b73a0b47a03dbef18a7f1d0ad17346a982c658d5660a0-init/diff:/var/lib/docker/overlay2/cfef35f2fd2430f54798e47b3ce3056bbd96fa29637ba2fa8144daa1c925a355/diff","MergedDir": "/var/lib/docker/overlay2/46c4ebdbc616cb8d052b73a0b47a03dbef18a7f1d0ad17346a982c658d5660a0/merged","UpperDir": "/var/lib/docker/overlay2/46c4ebdbc616cb8d052b73a0b47a03dbef18a7f1d0ad17346a982c658d5660a0/diff","WorkDir": "/var/lib/docker/overlay2/46c4ebdbc616cb8d052b73a0b47a03dbef18a7f1d0ad17346a982c658d5660a0/work"},"Name": "overlay2"},"Mounts": [],"Config": {"Hostname": "22249409fb3c","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"Tty": false,"OpenStdin": false,"StdinOnce": false,"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"],"Cmd": ["/bin/bash","-c","while true;do echo xiakucao;sleep 1;done"],"Image": "centos","Volumes": null,"WorkingDir": "","Entrypoint": null,"OnBuild": null,"Labels": {"org.label-schema.build-date": "20210915","org.label-schema.license": "GPLv2","org.label-schema.name": "CentOS Base Image","org.label-schema.schema-version": "1.0","org.label-schema.vendor": "CentOS"}},"NetworkSettings": {"Bridge": "","SandboxID": "b02c97f64a8992dc0f322a5acc0d2871115ff1654e680a06bdb86591659fef10","SandboxKey": "/var/run/docker/netns/b02c97f64a89","Ports": {},"HairpinMode": false,"LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"EndpointID": "daa0dad6de8bfdaab015d01972c6e0e7ff1518b23d839a9407c81b15c14d3564","Gateway": "172.17.0.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.3","IPPrefixLen": 16,"IPv6Gateway": "","MacAddress": "02:42:ac:11:00:03","Networks": {"bridge": {"IPAMConfig": null,"Links": null,"Aliases": null,"MacAddress": "02:42:ac:11:00:03","NetworkID": "f9a1764ef63ab36cfd232cf326edc32a337b8722c30a9964659b044b0fecf5c4","EndpointID": "daa0dad6de8bfdaab015d01972c6e0e7ff1518b23d839a9407c81b15c14d3564","Gateway": "172.17.0.1","IPAddress": "172.17.0.3","IPPrefixLen": 16,"IPv6Gateway": "","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"DriverOpts": null,"DNSNames": null}}}}
]（4）进入容器的命令与拷贝命令
exec进入容器用bash命令，（run是创建并进入，exec仅进入容器）
exec进入容器后会开启一个新的终端，可以在里面进行操作
[root@aliyun_docker ~]# docker exec -it 22249409fb3c /bin/bash
[root@22249409fb3c /]#
attach命令 进入正在执行的终端，不会启动新的进程
[root@aliyun_docker ~]# docker attach 22249409fb3c
xiakucao
xiakucao
xiakucao
xiakucao从容器内拷贝文件到主机上
只要容器还在，容器内的文件就不会消失
[root@aliyun_docker ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0eb80da8ce30 centos "/bin/bash" About a minute ago Up About a minute agitated_bhaskara
[root@aliyun_docker ~]# docker attach 0eb80da8ce30
[root@0eb80da8ce30 home]# cd /home
[root@0eb80da8ce30 home]# ls
[root@0eb80da8ce30 home]# touch test.java
[root@0eb80da8ce30 home]# exit
exit
[root@aliyun_docker ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0eb80da8ce30 centos "/bin/bash" 2 minutes ago Exited (0) 6 seconds ago agitated_bhaskara
[root@aliyun_docker ~]# docer cp 0eb80da8ce30:/home/test.java /home
-bash: docer: command not found
[root@aliyun_docker ~]# docker cp 0eb80da8ce30:/home/test.java /home
Successfully copied 1.54kB to /home
[root@aliyun_docker ~]#
参考链接
阿里云镜像加速
docker官网文档
视频教程b站狂神说java
