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What is a docker container? In general, people's understanding of docker containers may stay at the conceptual level, but relatively little is known about the application scenarios and usage of docker containers. Today I will talk to you about the specific use of docker containers.

Docker is a lightweight "virtual machine" open source tool for running applications in a Linux container. The difference between Docker and a virtual machine is that a virtual machine uses virtualization technology to virtualize multiple operating systems, each of which is isolated. Docker is an open source application container engine, you still need to install the operating system on your computer, and then install the manager of the Docker container. Virtual machines are virtualized at the hardware level, while Docker is virtualized at the operating system level Virtual machines are built by simulating the use of hardware operating system Docker packaging applications to simplify deployment without the underlying hardware migration example: server migration from Tencent Cloud to Aliyun Docker Core concept Image Container Warehouse CentOS installation Docker two ways to use curl to obtain docker installation script to install use yum repository to install dockerdocker installation settings mirror source Install docker [root @ localhost ~] # yum install-y\ > yum-utils\ / / set source tool > device-mapper-persistent-data\ / / Mapping tool > lvm2 [root@localhost ~] # yum-config-manager-- add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo / / load Ali cloud image source [root@localhost ~] # yum install docker -ce-y / install docker container [root@localhost ~] # systemctl stop firewalld.service [root@localhost ~] # setenforce 0 [root@localhost ~] # systemctl start docker / / Open docker container [root@localhost ~] # systemctl enable docker / / set boot self-startup [root@localhost ~] # ps aux | grep docker / / check whether the docker process is enabled [root@localhost ~] # docker version / / Check the version [root@localhost ~] # docker search nginx / / search for public images [root@localhost ~] # docker pull nginx / / download images for image acceleration

Log in to Aliyun website-console-Product Service-Container Image Service-Image Accelerator-Select centos

[root@localhost ~] # tee / etc/docker/daemon.json "registry-mirrors": ["https://3a8s9zx5.mirror.aliyuncs.com"]>} > EOF {" registry-mirrors ": [" https://3a8s9zx5.mirror.aliyuncs.com"]}[root@localhost ~] # systemctl daemon-reload / / reload daemon [root@localhost ~] # systemctl restart docker/ / restart the docker service [root@localhost ~] # Docker pull nginx / / download the nginx image [root@localhost ~] # docker images / / View the downloaded image information REPOSITORY TAG IMAGE ID CREATE SIZEnginx latest f7bb5701a33c 4 days ago 126MBdocker Image basic Operation Container 1: 192.168.80.12 Container 2: 192.168.80.13 [root@localhost ~] # docker inspect F7bb5701a33c / / View image information [root@localhost ~] # docker tag nginx:latest nginx:web / / add a new tag [root@localhost ~] # docker images / / View Image REPOSITORY TAG IMAGE ID CREATED SIZEnginx latest f7bb5701a33c 4 days ago 126MBnginx web F7bb5701a33c 4 days ago 126MB// regenerates a mirror The original one will not disappear [root@localhost ~] # docker images | grep web / / View the image labeled web nginx web f7bb5701a33c 4 days ago 126MB [root@localhost ~] # docker rmi nginx:web / / Delete the image Or directly follow the ID number Untagged: nginx:web [root@localhost ~] # docker imagesREPOSITORY TAG IMAGE ID CREATED SIZEnginx latest f7bb5701a33c 4 days ago 126MB [root@localhost ~] # cd / opt/ [root@localhost opt] # docker save-o nginx nginx:latest / / check out the image [root@localhost opt] # lscontainerd Nginx rh [root@localhost opt] # scp / opt/nginx root@192.168.80.13:/opt/ remote copy to 13 server to start another virtual machine with docker (192.168.80.13) [root@localhost opt] # docker load

< nginx //载入镜像//或者使用docker load --input 存出文件名[root@localhost opt]# docker images //查看镜像信息REPOSITORY TAG IMAGE ID CREATED SIZEnginx latest f7bb5701a33c 4 days ago 126MB回到原虚拟机（192.168.80.12）[root@localhost opt]# docker tag nginx:latest nginx:web //修改标签[root@localhost opt]# docker login //登录docker（你需要注册）Username: //用户名Password: //密码[root@localhost opt]# docker push nginx:web //上传公有仓库docker容器基本操作[root@localhost opt]# docker create -it nginx:latest /bin/bash //基于镜像创建一个容器 -i让容器的标准输入保持打开，-t让docker分配一个伪终端36fdfb0925ba040c094d585d70a3481bd450c7d39e6636ceeb10b5c1b9743593[root@localhost opt]# docker ps -a //-a列出最近一次启动的容器CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES36fdfb0925ba nginx:latest "/bin/bash" 3 seconds ago Created mystifying_dijkstra[root@localhost opt]# docker start 36fdfb0925ba //开启容器36fdfb0925ba[root@localhost opt]# docker ps -a //查看此时容器状态为开启CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES36fdfb0925ba nginx:latest "/bin/bash" 16 minutes ago Up 6 seconds 80/tcp mystifying_dijkstra操作步骤[root@localhost opt]# docker search centos7 //查看找centos7镜像[root@localhost opt]# docker pull paigeeworld/centos7 //下载镜像[root@localhost opt]# docker images //查看镜像REPOSITORY TAG IMAGE ID CREATED SIZEnginx latest f7bb5701a33c 4 days ago 126MBnginx web f7bb5701a33c 4 days ago 126MBpaigeeworld/centos7 latest 4cbe7aa905e7 5 years ago 382MB[root@localhost opt]# docker create -it paigeeworld/centos7 /bin/bash //创建容器c48649c8cee9124cb456be4f93882e6dff16f88ba45051731138142d99293dfe[root@localhost opt]# docker ps -a //查看容器CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc48649c8cee9 paigeeworld/centos7 "/bin/bash" 4 seconds ago Created relaxed_curran36fdfb0925ba nginx:latest "/bin/bash" 24 minutes ago Exited (0) 3 minutes ago mystifying_dijkstra[root@localhost opt]# docker start c48649c8cee9 //开启容器c48649c8cee9[root@localhost opt]# docker ps -a //查看容器CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc48649c8cee9 paigeeworld/centos7 "/bin/bash" 34 seconds ago Up 7 seconds relaxed_curran36fdfb0925ba nginx:latest "/bin/bash" 24 minutes ago Exited (0) 3 minutes ago容器的基本操作[root@localhost opt]# docker run paigeeworld/centos7 /usr/bin/bash -c ls / //docker run直接下载镜像，创建容器，并开启，进入容器执行命令，退出binbootdevetchome[root@localhost opt]# docker ps -a //查看容器CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc48649c8cee9 paigeeworld/centos7 "/bin/bash" 9 minutes ago Up 9 minutes relaxed_curran[root@localhost opt]# docker exec -it c48649c8cee9 /bin/bash //进入容器（必须为开启状态）bash-4.2# ls /bin dev home lib64 media opt root sbin sys usrboot etc lib lost+found mnt proc run srv tmp varbash-4.2# exit //退出容器exit[root@localhost opt]# docker ps -a //此时容器状态还是开启的状态CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc48649c8cee9 paigeeworld/centos7 "/bin/bash" 10 minutes ago Up 10 minutes relaxed_curran[root@localhost opt]# docker stop c48649c8cee9 //关闭容器c48649c8cee9[root@localhost opt]# docker ps -a //此时容器为退出状态CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc48649c8cee9 paigeeworld/centos7 "/bin/bash" 11 minutes ago Exited [root@localhost opt]# docker run -d paigeeworld/centos7 /bin/bash -c "while true;do echo hello;done" //持续在后台执行，-d在后台进行运行398f3d27f36b7f59a2167a71e71f61064e4e9a0808dfa13404caec0280a0b9c2[root@localhost opt]# docker ps -a //查看容器一直是开启状态CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES398f3d27f36b paigeeworld/centos7 "/bin/bash -c 'while…" 9 seconds ago Up 7 seconds [root@localhost opt]# docker export 36fdfb0925ba >

Nginx_c / / Container Export [root@localhost opt] # lscontainerd nginx nginx_c rh [root@localhost opt] # scp / opt/nginx_c root@192.168.13.129:/opt/ remote copy to another virtual machine to another virtual machine [root@localhost opt] # lscontainerd nginx nginx_c rh [root@localhost opt] # cat nginx_c | docker import-nginx:web / / Container import generates Mirror without creating a container sha256:1488d058197863aedd46d289eeb11dc39f19a2b855c3ecf383331a4d0bac568c [root@localhost opt] # docker imagesREPOSITORY TAG IMAGE ID CREATED SIZEnginx web 1488d0581978 5 seconds ago 125MB [root@localhost opt] # docker ps-aCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES [root@localhost opt] # docker ps-a | awk'{print "docker rm" $1}'| bash / / batch delete container docker resource control limit cpu usage rate limit cpu usage by modifying the configuration file cpu.cfs_quota_us to achieve proportional sharing of cpudocker run-cpu-shares 1024 container Adocker run-cpu-shares 1024 container Bdocker run -- cpu-shares 2048 Container C use-- cpuset-cpus option to restrict the right to use the cpu kernel [root@localhost opt] # docker run-- cpu-quota 20000 nginx:latest / / set 20% limit [root@localhost opt] # cd / sys/fs/cgroup/cpu/docker/ [root@localhost opt] # cat cpu.cfs_quota_us-1 [root@localhost opt] # docker run-itd-name C1-cpu-shares 512 paigeeworld/centos7 / / create container C1 set weight Make the proportion of c1 and c2 cpu resources 33.3% and 66.7% ec4ab03a7969eebe4746cfe67184bc2c6f9c97e81b22bc2ffab452820a78a0a7 [root @ localhost opt] # docker run-itd-- name c2-- cpu-shares 1024 paigeeworld/centos7c688b014329c6a33b0d66947f4489a1a1cb6febc321090ecb4a82b68ae6df250 [root@localhost opt] # docker ps-a / View Container CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESc688b014329c Paigeeworld/centos7 "/ bin/bash" About a minute ago Up About a minute c2ec4ab03a7969 paigeeworld/centos7 "/ bin/bash" About a minute ago Up About a minute C1 [root@localhost opt] # docker run-- name c3-- cpuset-cpus 0Power1 paigeeworld/centos7 / / limit the use of containers specified Cpu [root@localhost opt] # docker ps-a / / View container information CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES751409a81682 paigeeworld/centos7 "/ bin/bash" 8 seconds ago Exited (0) 7 seconds ago c3 [root@localhost opt] # docker run-- name c5-m 512m paigeeworld/centos7 / / memory usage limit [root@localhost opt] # docker ps-aCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES8c3101668345 paigeeworld/centos7 "/ bin/bash" 5 seconds ago Exited (0 ) 4 seconds ago c5 limits on blkio-- device-read-bps: limit the amount of data that can be written to a device-- device-write-bps: limit the amount of data written to a device-- device-read-iops: limit the number of times to read a device-- device-write-iops: limit the number of times to write to a device [root@localhost opt] # docker run-d-- device-write-bps / dev/sda: 30mb paigeeworld/centos7docker data management data management operation is convenient to view the data generated in the container to achieve data sharing among multiple containers. Two management methods: data volume data volume container data volume data volume is a special directory for container use data volume container data volume container is a common container data volume sharing (host and container sharing) [root@localhost ~] # docker pull centos / / download image [root@localhost] # docker run-v / var/www:/data1-- name web1-it centos / bin/bash / / share of associated hosts and containers [root@2483bee94f1a /] # cd data1/ [root@2483bee94f1a data1] # echo "123" > test01.txt [root@2483bee94f1a data1] # exit exit [root@localhost ~] # cat / var/www/test01.txt 123 data volume container sharing (containers and containers) [root@localhost ~] # docker run-- name web100-v / data1-v / data2-it centos / bin/bash / / create a web100 container with two volumes as data1 2 [root@ba6a328c068e /] # cd data1/ [root@ba6a328c068e data1] # echo "111" > 111.txt / / write contents in the directory [root@ba6a328c068e data1] # cd.. / data2/ [root@ba6a328c068e data2] # echo" 222" > 222.txt [root@ba6a328c068e data2] # exitexit [root@localhost ~] # docker run-it-volumes-from web100-it centos / bin/bash / / Mount the new container to the data volume container web100 [root@3f64be49dadd /] # cat data1/111.txt 111 [root@3f64be49dadd /] # cat data2/222.txt 222

These are the details of the introduction and use of the docker container. Have you learned anything after reading it? If you want to know more about it, you are welcome to follow the industry information!

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