创建镜像
创建镜像的方法有三种：
- 基于已有的容器创建
- 基于本地模板导入
- 基于dockerfile
基于已有的容器创建
主要使用docker commit 命令，命令格式：
docker commit [OPTIONS] CONTAINER [REPOSITORY[:tag]]，主要包括： -a ,--author="" 作者信息 -m,--message=""提交消息 -p,--pause=true 提交时暂停容器
例如：
# docker run -it centos /bin/bash [root@d7e7ac1cbca2 /]# touch test [root@d7e7ac1cbca2 /]# ls anaconda-post.log bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys test tmp usr var # docker commit -m "add a file" -a "kafeikele" de6 centos_copy 5d318afa9e6f7fdb755db97e29e3860b752f24b0b50e6bfa0b7e457450802c0e # docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE centos_copy latest 5d318afa9e6f 13 seconds ago 196.7 MB
基于本地模板导入
推荐使用openVZ提供的模板来创建
https://openvz.org/Download/templates/precreated
#cat centos-7-x86_64-minimal.tar.gz.crdownload | docker import - centos:latest
存出和导入镜像
# docker images centos 7.1.1503 47a77536ad4c 8 weeks ago 212.1 MB # docker save -o centos_7.1.tar centos:7.1.1503 # docker load --input centos_7.1.tar # docker load < centos_7.1.tar
基于dockerfile
之后的内容详细介绍
运行第一个docker容器
# docker run centos echo "hello world" Unable to find image 'centos:latest' locally latest: Pulling from centos 47d44cb6f252: Pull complete 168a69b62202: Pull complete 812e9d9d677f: Pull complete 4234bfdd88f8: Pull complete ce20c473cd8a: Pull complete centos:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security. Digest: sha256:3aaab9f1297db9b013063c781cfe901e2aa6e7e334c1d1f4df12f25ce356f2e5 Status: Downloaded newer image for centos:latest hello world
命令说明：
docker run :标准容器启动命令
centos: 镜像名称，默认是latest
echo和后面的内容：容器启动后执行的命令
启动一个交互式容器
docker run -it centos /bin/bash
*注：-t标示在心容器内指定一个伪终端或终端，-i标示允许我们对容器内的STDIN进行交互
以服务方式启动一个docker容器
如果你实际测试，估计也发现了，第一个“hello world”容器启动后执行完echo命令就退出了，而第二个交互式的容器，只要用户退出当前容器的bash，容器也退出了。这明显不能满足一个服务长时间运行的要求，好找docker run提供了‘-d’参数，可以实现将容器以守护进程方式启动。
docker run -d centos /bin/bash -c "while true; do echo Docker,hello world; sleep 2;
179fc7f17c358834364d23112aa26d6a9e1875b2281563720425f62a8f1b5c33
这个长的字符串叫做容器ID。它是容器的唯一标识，所以我们可以使用它来操作容器，比如查看日志、停止或删除容器等。
dock logs 179fc7f17c358834364d
而为什么使用一个死循环来输出呢？
因为如果不是死循环，一次输出后，容器中的进程就结束了。容器的唯一进程都结束了，容器就停止了。因此如果要在容器中运行具体的服务，这项服务本身在容器中也必须是已守护进程方式运行的。
docker run [OPTIONS] IMAGE [COMMAND] [ARG...] 主要选项： -d : 以后台进行方式运行容器 -t : 提供一个伪终端 -i : 提供交互输入，一般与“-t”一起使用，如果只提供“-i”选项，则容器启动后是无法退出的 -v : 映射一个volume给容器，如： -p /data/www:/var/www/html -p : 将容器的端口映射给宿主机，如： -p 8080:80
更多命令操作
Docker help
查看docker的子命令，直接敲docker或完整的docker help就可以了:
[root@VM_27_98_centos ~]# docker help Commands: attach Attach to a running container build Build a container from a Dockerfile commit Create a new image from a container's changes cp Copy files/folders from the containers filesystem to the host path diff Inspect changes on a container's filesystem events Get real time events from the server export Stream the contents of a container as a tar archive history Show the history of an image images List images import Create a new filesystem image from the contents of a tarball info Display system-wide information inspect Return low-level information on a container kill Kill a running container load Load an image from a tar archive login Register or Login to the docker registry server logs Fetch the logs of a container port Lookup the public-facing port which is NAT-ed to PRIVATE_PORT ps List containers pull Pull an image or a repository from the docker registry server push Push an image or a repository to the docker registry server restart Restart a running container rm Remove one or more containers rmi Remove one or more images run Run a command in a new container save Save an image to a tar archive search Search for an image in the docker index start Start a stopped container stop Stop a running container tag Tag an image into a repository top Lookup the running processes of a container version Show the docker version information wait Block until a container stops, then print its exit code
常用命令
总结一下常用命令:
- docker version 查看docker的版本号，包括客户端、服务端、依赖的Go等
- docker info 查看系统(docker)层面信息，包括管理的images, containers数等
- docker search <image> 在docker index中搜索image
- docker pull <image> 从docker registry server 中下拉image
- docker push <image|repository> 推送一个image或repository到registry
- docker push <image|repository>:TAG 同上，指定tag
- docker inspect <image|container> 查看image或container的底层信息
- docker images TODO filter out the intermediate image layers (intermediate image layers 是什么)
- docker images -a 列出所有的images
- docker ps 默认显示正在运行中的container
- docker ps -l 显示最后一次创建的container，包括未运行的
- docker ps -a 显示所有的container，包括未运行的
- docker logs <container> 查看container的日志，也就是执行命令的一些输出
- docker rm <container...> 删除一个或多个container
- docker rm `docker ps -a -q` 删除所有的container
- docker ps -a -q | xargs docker rm 同上, 删除所有的container
- docker rmi <image...> 删除一个或多个image
- docker start/stop/restart <container> 开启/停止/重启container
- docker start -i <container> 启动一个container并进入交互模式
- docker attach <container> attach一个运行中的container
- docker run <image> <command> 使用image创建container并执行相应命令，然后停止
- docker run -i -t <image> /bin/bash 使用image创建container并进入交互模式, login shell是/bin/bash
- docker run -i -t -p <host_port:contain_port> 将container的端口映射到宿主机的端口
- docker commit <container> [repo:tag] 将一个container固化为一个新的image，后面的repo:tag可选
- docker build <path> 寻找path路径下名为的Dockerfile的配置文件，使用此配置生成新的image
- docker build -t repo[:tag] 同上，可以指定repo和可选的tag
- docker build - < <dockerfile> 使用指定的dockerfile配置文件，docker以stdin方式获取内容，使用此配置生成新的image
- docker port <container> <container port> 查看本地哪个端口映射到container的指定端口，其实用docker ps 也可以看到
具体实例
docker images 列出本地所有镜像，这些都是使用Dockerfile构建的镜像 [root@VM_159_91_centos ~]# docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE pt/test v1 2bfc44a4ad8f 4 days ago 196.5 MB pt/tomcat_smq v1 987073773bfd 5 days ago 754.9 MB pt/tomcat_msg v1 e82f90cf31c9 5 days ago 754.9 MB centos latest 97cad5e16cb6 2 weeks ago 196.5 MB registry latest 5c929a8b587a 4 weeks ago 33.27 MB google/cadvisor latest 089623f9fe9e 6 weeks ago 47.79 MB docker ps –a 列出创建的所有容器 可以看到他们的状态都是exited,说明这些容器都是关闭状态，没有启动 [root@VM_159_91_centos ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7f76edae027d pt/test:v1 "/bin/bash" 4 days ago Exited (137) 4 days ago jolly_torvalds 05cf1c1dbf71 pt/tomcat_smq:v1 "/usr/local/smq-tomc 5 days ago Exited (143) 20 hours ago smq 1c296658025a pt/tomcat_msg:v1 "/usr/local/msg-tomc 5 days ago Exited (143) 4 days ago msg docker start 05cf1c 启动容器，start后面跟的是容器ID，状态变成了up,且映射了一个端口，把容器里面的8080端口映射到宿主机的6180上面 [root@VM_159_91_centos ~]# docker start 05cf1c1dbf71 05cf1c1dbf71 [root@VM_159_91_centos ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7f76edae027d pt/test:v1 "/bin/bash" 4 days ago Exited (137) 4 days ago jolly_torvalds 05cf1c1dbf71 pt/tomcat_smq:v1 "/usr/local/smq-tomc 5 days ago Up 28 seconds 0.0.0.0:6180->8080/tcp smq docker stop 05cf1c 关闭容器 [root@VM_159_91_centos ~]# docker stop 05cf1c1dbf71 05cf1c1dbf71 [root@VM_159_91_centos ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7f76edae027d pt/test:v1 "/bin/bash" 4 days ago Exited (137) 4 days ago jolly_torvalds 05cf1c1dbf71 pt/tomcat_smq:v1 "/usr/local/smq-tomc 5 days ago Exited (143) 3 seconds ago smq tag做标记 docker tag pt/tomcat_search:v1 IP:5000/pt/tomcat_search:v1 [root@VM_159_91_centos ~]# docker tag pt/tomcat_search:v1 IP:5000/pt/tomcat_search:v1 (ip填写自己的地址) [root@VM_159_91_centos ~]# docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE pt/tomcat_search v1 b5681406505f 6 days ago 755.2 MB IP/pt/tomcat_search v1 b5681406505f 6 days ago 755.2 MB push推送到镜像仓库 docker push IP:5000/pt/tomcat_search:v1 IP替换成自己的真实IP [root@VM_159_91_centos ~]# docker push IP:5000/pt/tomcat_search:v1 The push refers to a repository [IP:5000/pt/tomcat_search] (len: 1) b5681406505f: Image already exists 4056159949ab: Image already exists e9970493708d: Image already exists a06c57a073b3: Image already exists 84551ae56dd4: Image already exists 49e5958f14aa: Image already exists b484689c1f77: Image already exists a336ec9f22dc: Image already exists 31f25b288c4a: Image already exists 65d689569b3f: Image already exists 411a7bdc8e8d: Image already exists c863857a498b: Image already exists 97cad5e16cb6: Image already exists 05fe84bf6d3f: Image already exists af0819ed1fac: Buffering to Disk af0819ed1fac: Image successfully pushed 3690474eb5b4: Image already exists Digest: sha256:e7d15d45fa95a9d0b8d2e7efbecfdce262f563e91a3af4a738970d55bbe69b55 Docker pull 在另外一台机器就可以pull下来刚才上传到镜像仓库里面的镜像 登录另外一台服务器 ＃docker pull IP:5000/pt/tomcat_search:v1 [root@VM_27_98_centos ~]# docker pull 10.104.159.91:5000/pt/tomcat_search:v1 v1: Pulling from IP:5000/pt/tomcat_search 411a7bdc8e8d: Pull complete 65d689569b3f: Pull complete 31f25b288c4a: Pull complete a336ec9f22dc: Pull complete b484689c1f77: Pull complete 49e5958f14aa: Pull complete 84551ae56dd4: Pull complete a06c57a073b3: Pull complete e9970493708d: Pull complete 4056159949ab: Pull complete b5681406505f: Already exists 3690474eb5b4: Already exists af0819ed1fac: Already exists 05fe84bf6d3f: Already exists 97cad5e16cb6: Already exists c863857a498b: Already exists Digest: sha256:e7d15d45fa95a9d0b8d2e7efbecfdce262f563e91a3af4a738970d55bbe69b55 Status: Downloaded newer image for IP:5000/pt/tomcat_search:v1 #docker pull centos 下载镜像到本地 #docker create -it ubuntu:latest 创建一个容器 Unable to find image 'ubuntu:latest' locally latest: Pulling from ubuntu 58488e45273c: Pull complete 25810b66099e: Pull complete 6571ba684f54: Pull complete 6ed49a73d8f0: Pull complete c53777cbfc31: Pull complete 56465e1e45d2: Pull complete Digest: sha256:312986132029d622ae65423ca25d3a3cf4510de25c47b05b6819d61e2e2b5420 Status: Downloaded newer image for ubuntu:latest 1330233e50aba7fca99e5914bd28dd89321bc86ec35fb36b4775d3424337c190 #docker start 1330233e
进入容器
方法一： # docker attach a54615a88787 后面跟的是容器名或者id，退出后docker容器也退出，不常用 方法二： # docker exec -it a54615a88787 /bin/bash 跟的是容器名或者id 方法三： yum -y install util-linux # docker inspect --format "{{.State.Pid}}" stupefied_cray 最后面跟的是容器的名称 4899 # nsenter --target 4899 --mount --uts --ipc --net --pid
脚本
#!/bin/bash CNAME=$1 CPID=$(docker inspect --format "{{.State.Pid}}" $CNAME) nsenter --target $CPID --mount --uts --ipc --net –pid
2016-10-28 01:00:26