Learning Docker, you first need to understand the basic concepts of Docker, and then began to "hands-on" a (that is, knock Docker command). Docker command more, here we summarize Docker commonly used commands for easy access to small partners.
Docker is based on the go language development, the underlying technology (Linux under) mainly is based on a process level lightweight cgroups, namespace and file a joint virtualization technology solutions. Since Docker process isolation independently of other processes on the host, it is also known container, the container on the basis Docker conducted further packaging, from the file system, process isolation to the network, which greatly simplifies the creation of management container maintenance work, reducing the threshold for developers to use, so it became popular in recent years (after all, the underlying technology before Docker Docker appears to have existed).
Docker command has two categories, namely the server and client command command, the former is operating docker server (dockerd), which is commonly used by developers docker command, more Docker command can be used docker helpto view.
- Client command: command format is substantially docker [OPTIONS] COMMAND [arg ...];
- Server commands: the basic command format is dockerd [OPTIONS].
Client command
mounting the docker centos command may be used yum install docker, the need to install mac docker-for-mac, use the command wget http://mirrors.aliyun.com/docker-toolbox/mac/docker-for-mac/stable/Docker.dmg. After installation can use the following command Docker:
service docker start 启动docker服务
docker version/info 查看docker版本/信息
docker inspect 查看容器详细信息
docker inspect -f {{.State.Pid}} xxxx 查看容器对应的pid
docker logs 查看对应容器日志
Docker There are two basic concepts: the mirror and the container, the former is a container packed executable file, which is running Docker instance, the relationship between both similar 可执行文件and 进程concepts.
Mirroring Command
Mirror-related commands are searching, viewing, deleting, archiving and loading, etc., as follows:
docker images 查看所有本地镜像，或者使用命令 docker image ls
docker search xxx 搜索官方仓库中的镜像
docker pull xxx:tag 下载镜像，也可以使用docker push 推送自己的镜像，docker run xxx命令会启动容器，当本地没有容器镜像是会从仓库中拉取
docker rmi imageName 删除本地一个或多个镜像，注意不要和docker rm删除容器命令混淆
docker rm xxx 删除一个或多个容器
docker history ubuntu:18.04 查看Ubuntu镜像的创建过程（各个层内容）
docker save -o ubuntu_18.04.tar ubuntu:18.04 导出镜像到本地文件ubuntu_18.04.tar
docker load -i ubuntu_18.04.tar 加载镜像，或者使用命令 docker < ubuntu_18.04.tar
Container command
Around the container, Docker provides a very rich operational command, allows the entire lifecycle of customers in the efficient management of the container. You can use docker container helpthe command to view the Docker support vessel operation sub-command:
docker ps 列出所有运行中的容器
docker ps -a 列出所有容器，包括停止状态的
docker ps -a -q 列出所有镜像的id
docker rm containerId 删除某一个镜像
docker rm $(docker ps -a -q) 删除所有处于终止状态的容器，注意不能删除正在运行中的容器
docker run -it --rm ubuntu:14:04 bash -it 这是两个参数，-t是开一个终端（伪终端绑定到容器的标准输入上），-i是交互式命令让容器的标准输入保持打开。--rm是容器退出后删除，默认情况下容器退出不会自动删除，方便排查问题。ubuntu:14:04使用的启动镜像。bash放在镜像后面的命令。执行exit命令从容器中退出时，容器会自动退出。有时候需要让容器已后台守护态运行，此时需要增加-d参数，比如docker urn -d ubuntu。
docker run ubuntu echo "hello world" 在docker容器中运行命令输出hello world
docker start containerId 启动处于created状态的容器
docker resetart containerId 重启处于运行状态的容器
docker stop containerId 停止容器运行
docker logs xxx 查看容器xxx输出信息
docker pause [container] 暂停容器，恢复使用命令docker unpause xxx
docker inspect [container] 查看容器的详细信息，创建时间、路径、状态配置等详细信息。
docker top [container] 查看容器内进程信息。
docker stats [container] 查看容器的CPU、内存、网络等统计信息，支持选项有：-a:输出所有统计信息，默认只输出运行中信息；-no-stream:不持续输出，默认会自动更新统计结果。
docker cp zzz.txt 26755872da4d:/tmp：将本地zzz.txt文件复制到容器26755872da4d的/tmp目录下，也可以使用命令将容器内文件复制到本地机器，docker cp 26755872da4d:/tmp/zzz.txt /tmp。
docker container diff 26755872da4d：container diff命令查看容器内文件系统的变更。
docker container port 26755872da4d：查看容器端口映射。
docker update --cpus 4 26755872da4d：限定容器使用CPU个数为4
container update command to update some configuration runtime container, mainly because some resource constraints share. The command format is docker [container] update [OPTIONS] CONTAINER [CONTAINER ...], of the support as follows:
❑ -blkio-weight uint16：更新块IO限制，10～1000，默认值为0，代表着无限制；
❑ -cpu-period int：限制CPU调度器CFS（Completely Fair Scheduler）使用时间，单位为微秒，最小1000；
❑ -cpu-quota int：限制CPU调度器CFS配额，单位为微秒，最小1000；
❑ -cpu-rt-period int：限制CPU调度器的实时周期，单位为微秒；
❑ -cpu-rt-runtime int：限制CPU调度器的实时运行时，单位为微秒；
❑ -c, -cpu-shares int：限制CPU使用份额；
❑ -cpus decimal：限制CPU个数；
❑ -cpuset-cpus string：允许使用的CPU核，如0-3,0,1；
❑ -cpuset-mems string：允许使用的内存块，如0-3,0,1；
❑ -kernel-memory bytes：限制使用的内核内存；
❑ -m, -memory bytes：限制使用的内存；
❑ -memory-reservation bytes：内存软限制；
❑ -memory-swap bytes：内存加上缓存区的限制，-1表示为对缓冲区无限制；
❑ -restart string：容器退出后的重启策略。
docker run parameters
docker run to start the container, the container can specify parameters launch policy, as follows:
-d 容器会在后台运行并不会把输出（STDOUT）打印到宿主机上
-t 让docker分配一个伪终端并绑定到容器的标准输入上
-i 让容器的标准输入保持打开
-p 映射本地端口和容器端口，格式为-p ip:hostPort:containerPort或者-p hostPort:containerPort。
-P 大写的P，使用 -P 标记时，Docker 会随机映射一个 49000~49900 的端口到内部容器开放的网络端口。
--rm 在容器执行完毕后将其删除，默认只能删除已停止的容器，如果想要删除正在运行中容器，可增加-f参数。
--name xxx 执行容器的name
Note that if the container will run for a long time, and it is docker run the specified command about, nothing to do with the -d parameter .
Operation container
Into the container
During operation of the container, the container is often necessary to perform an operation to enter a scene, use the command into the container:
attach：使用命令docker attach containerId/names进入容器，但是使用 attach 命令有时候并不方便。当多个窗口同时 attach 到同一个容器的时候，所有窗口都会同步显示。当某个窗口因命令阻塞时,其他窗口也无法执行操作了。注意，进入容器后，如果使用exit退出容器，那么容器也会停止运行，可以使用命令Ctrl+P+Q来退出但不关闭容器。
nsenter：nsenter 启动一个新的shell进程(默认是/bin/bash)，同时会把这个新进程切换到和目标(target)进程相同的命名空间，这样就相当于进入了容器内部。nsenter 要正常工作需要有 root 权限
exec：使用exec命令更加便捷，docker exec -it 775c7c9ee1e1 /bin/bash ，很方便的进入容器
Import / Export containers
docker export -o test.tar [container] 将某个容器导出到本地
docker import test.tar 导入某个容器导出文件（容器导出为镜像文件，这里相当于加载镜像文件）。实际上，既可以使用docker load命令来导入镜像存储文件到本地镜像库，也可以使用docker[container] import命令来导入一个容器快照到本地镜像库。这两者的区别在于：容器快照文件将丢弃所有的历史记录和元数据信息（即仅保存容器当时的快照状态），而镜像存储文件将保存完整记录，体积更大。此外，从容器快照文件导入时可以重新指定标签等元数据信息。
Port Mapping
When the container starts, if you do not specify the corresponding parameter in the outer container it is unable to access network applications and services within the container through the network. When some network applications running in the container, to let the external access them, you may be designated by port mapping or -P -p parameters. When the marker used -P (uppercase), Docker randomly mapped to a port of 49,000 - 49,900 vessel open interior network ports.
docker run -d -p 500:5000 xxxwebapp python app.py：启动容器并运行python app.py程序，映射本地500端口到容器5000端口。或者使用docker run -d -p 127.0.0.1:500:5000 xxxwebapp python app.py指定特定地址。
docker run -it --name zzz ubuntu bash
docker run -it --name zzz2 --link zzz:zzz ubuntu bash zzz2容器和zzz容器建立互联关系。
--link参数的格式为--link name:alias，其中name是要链接的容器的名称，alias是别名。
Docker相当于在两个互联的容器之间创建了一个虚机通道，而且不用映射它们的端口到宿主主机上。
在启动db容器的时候并没有使用-p和-P标记，从而避免了暴露数据库服务端口到外部网络上。
Data Management
Docker data management is divided into two kinds:
- Data volume: container directly mapped to the local data;
- Data volume container: the container to maintain a certain data volume.
Data volume (Data Volumes) is a container for use in a special directory, it will host operating system directory directly mapped into the container, similar to mount behavior in Linux. If mounted directly to a file container, file editing tool, including vi or sed --in-place time, may cause changes in the file inode. From Docker 1.1.0 onwards, this report will lead to error messages. Therefore, the recommended way is to directly mount the directory where the file into the container.
Server command
dockerd command is responsible for starting the server master process, supported by the command options shown in the following table:
Docker command map
Finally come the end of it as a Docker map:
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