1、简介python
Docker 是一个开源的应用容器引擎,让开发者能够打包他们的应用以及依赖包到一个可移植的容器中,而后发布到任何流行的 Linux 机器上,也能够实现虚拟化。容器是彻底使用沙箱机制,相互之间不会有任何接口(相似 iPhone 的 app)。几乎没有性能开销,能够很容易地在机器和数据中心中运行。mysql
Docker的理念:一个容器只运行一个服务linux
Docker官网口号包含了Build,Shipand Run Any App,Anywhere,即任何应用,均可以构建、发布、运行于任何环境,将环境的影响因素降至最低,统一地掌控整个应用的生命周期。sql
Docker的官方文档:http://docs.docker.com/docker
2、安装json
一、安装epel源 注释:默认CentOS6.x提供的yum源里没有docker的安装包,在这里咱们借助EPEL源。 # rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm # sed -i 's@^#@@' /etc/yum.repos.d/epel.repo # sed -i 's@mirrorlist@#mirrorlist@' /etc/yum.repos.d/epel.repo 二、安装docker # yum -y remove docker # yum install docker-io 三、启动docker守护进程 # service docker start # chkconfig docker on 四、检查docker是否已经正确安装并运行 # docker info 五、查看docker的版本 # docker -v
3、命令参数ubuntu
一、docker命令帮助参数bash
[root@localhost ~]# docker Usage: docker [OPTIONS] COMMAND [arg...] Commands: attach Attach to a running container build Build an p_w_picpath from a Dockerfile commit Create a new p_w_picpath from a container's changes cp Copy files/folders from a container's filesystem to the host path create Create a new container diff Inspect changes on a container's filesystem events Get real time events from the server exec Run a command in a running container export Stream the contents of a container as a tar archive history Show the history of an p_w_picpath p_w_picpaths List p_w_picpaths import Create a new filesystem p_w_picpath 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 p_w_picpath from a tar archive login Register or log in to a Docker registry server logout Log out from a Docker registry server logs Fetch the logs of a container port Lookup the public-facing port that is NAT-ed to PRIVATE_PORT pause Pause all processes within a container ps List containers pull Pull an p_w_picpath or a repository from a Docker registry server push Push an p_w_picpath or a repository to a Docker registry server restart Restart a running container rm Remove one or more containers rmi Remove one or more p_w_picpaths run Run a command in a new container save Save an p_w_picpath to a tar archive search Search for an p_w_picpath on the Docker Hub start Start a stopped container stop Stop a running container tag Tag an p_w_picpath into a repository top Lookup the running processes of a container unpause Unpause a paused container version Show the Docker version information wait Block until a container stops, then print its exit code
二、比较经常使用命令参数服务器
查看Docker的版本信息 # docker version 在Docker Hub上搜索一个指定镜像 # docker search 在Docker Hub上搜索一个指定镜像并至少有10颗星 # docker search -s 10 ubuntu 从一个Docker的注册服务器上拉取一个镜像或一个私有仓库 # docker pull ubuntu 查看镜像列表 # docker p_w_picpaths 在一个新的容器中运行一个命令 # docker run 移除一个或多个镜像 # docker rmi 移除一个或多个容器 # docker rm 附着一个运行的容器 # docker attach 运行一个命令在一个运行的容器中 # docker exec 从一个Dockerfile文件中构建一个镜像 # docker build 查看镜像构建历史 # docker history 查看容器更为详细的配置信息 # docker inspect 保存一个镜像对归档tar中 # docker save 从一个归档tar中加载一个镜像 # docker load 启动、中止、重启一个运行的容器 # docker start| stop| restart 杀掉一个正在运行的容器 # docker kill 额外补充 进入容器命令: docker attach:登录到运行的容器中 docker exec:在宿主机上运行命令到容器内部,相似在打开一个容器的终端 docker nsenter:链接到容器,须要容器PID
4、建立ssh镜像和镜像打包网络
一、从Docker Hub上下载ubuntu镜像
[root@localhost ~]# docker pull ubuntu:14.04 [root@localhost ~]# docker p_w_picpaths REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE ubuntu 14.04 b7cf8f0d9e82 3 days ago 188.3 MB
二、基于镜像建立一个容器
[root@localhost ~]# docker run -it ubuntu:14.04 /bin/bash [root@localhost ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 88b6a8dfae4e ubuntu:14.04 "/bin/bash" 3 minutes ago Up 3 minutes modest_yalow
三、进入容器安装ssh服务
root@88b6a8dfae4e:/# apt-get update && apt-get install -y openssh-server root@0af7ccfd906e:/# echo 'root:redhat' | chpasswd root@10dbbd22172d:/# mkdir /var/run/sshd root@10dbbd22172d:/# sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/' /etc/ssh/sshd_config root@10dbbd22172d:/# sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd root@10dbbd22172d:/# exit [root@localhost ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 88b6a8dfae4e ubuntu:14.04 "/bin/bash" 10 minutes ago Exited (130) 18 seconds ago modest_yalow
四、构建一个ssh的镜像
[root@localhost ~]# docker commit 88b6a8dfae4e zhengyas/ubuntu:sshd 3f2225df36ff67cbda098318e83128f3965758eba3e4609a094c172b0c3b03c4 [root@localhost ~]# docker p_w_picpaths REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE zhengyas/ubuntu sshd 3f2225df36ff 21 seconds ago 251.1 MB ubuntu 14.04 b7cf8f0d9e82 3 days ago 188.3 MB
五、基于新镜像运行一个ssh容器
[root@localhost ~]# docker run -d -p 2222:22 zhengyas/ubuntu:sshd /usr/sbin/sshd -D 7ef47903cdb77ad9d98fd0dd3b102473d10ad3abea5311c030177db9ea9984c1 [root@localhost ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7ef47903cdb7 zhengyas/ubuntu:sshd "/usr/sbin/sshd -D" 4 seconds ago Up 4 seconds 0.0.0.0:2222->22/tcp hungry_ritchie
六、测试ssh容器是否可以正常链接
[root@localhost ~]# ssh root192.168.0.104 -p 2222 ssh: Could not resolve hostname root192.168.0.104: Name or service not known [root@localhost ~]# ssh root@192.168.0.104 -p 2222 The authenticity of host '[192.168.0.104]:2222 ([192.168.0.104]:2222)' can't be established. RSA key fingerprint is 0e:1e:4e:67:f3:4b:5a:c4:c2:f5:7b:e7:f0:2e:14:72. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '[192.168.0.104]:2222' (RSA) to the list of known hosts. root@192.168.0.104's password: Welcome to Ubuntu 14.04 LTS (GNU/Linux 3.2.0-61-generic x86_64) * Documentation: https://help.ubuntu.com/ The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. root@7ef47903cdb7:~# ifconfig eth0 Link encap:Ethernet HWaddr 02:42:ac:11:00:03 inet addr:172.17.0.3 Bcast:0.0.0.0 Mask:255.255.0.0 inet6 addr: fe80::42:acff:fe11:3/64 Scope:Link UP BROADCAST RUNNING MTU:1500 Metric:1 RX packets:47 errors:0 dropped:0 overruns:0 frame:0 TX packets:40 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:5638 (5.6 KB) TX bytes:6521 (6.5 KB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
七、镜像持久化,俗称镜像打包
镜像打包(Save)
[root@localhost ~]# docker save zhengyas/ubuntu > /root/sshd.tar
镜像导入(Load)
实验模拟 一、删除此sshd容器 [root@localhost ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7ef47903cdb7 zhengyas/ubuntu:sshd "/usr/sbin/sshd -D" 14 minutes ago Up 14 minutes 0.0.0.0:2222->22/tcp hungry_ritchie [root@localhost ~]# docker stop 7ef47903cdb7 7ef47903cdb7 [root@localhost ~]# docker rm 7ef47903cdb7 7ef47903cdb7 二、删除sshd镜像 [root@localhost ~]# docker rmi zhengyas/ubuntu:sshd Untagged: zhengyas/ubuntu:sshd Deleted: 3f2225df36ff67cbda098318e83128f3965758eba3e4609a094c172b0c3b03c4 [root@localhost ~]# docker p_w_picpaths REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE ubuntu 14.04 b7cf8f0d9e82 3 days ago 188.3 MB 三、导入打包的镜像 [root@localhost ~]# docker load < /root/sshd.tar [root@localhost ~]# docker p_w_picpaths REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE zhengyas/ubuntu sshd 3f2225df36ff 18 minutes ago 251.1 MB ubuntu 14.04 b7cf8f0d9e82 3 days ago 188.3 MB
5、基于Dockerfile来建立mysql镜像
一、建立Dockerfile文件
[root@localhost ~]# mkdir mysql_ubuntu [root@localhost ~]# cd mysql_ubuntu/ [root@localhost mysql_ubuntu]# cat Dockerfile FROM ubuntu:14.04 RUN apt-get update RUN apt-get -y install mysql-client mysql-server RUN sed -i -e"s/^bind-address\s*=\s*127.0.0.1/bind-address = 0.0.0.0/" /etc/mysql/my.cnf ADD ./startup.sh /opt/startup.sh EXPOSE 3306 CMD ["/bin/bash", "/opt/startup.sh"]
二、建立mysql服务启动脚本文件
[root@localhost mysql_ubuntu]# cat startup.sh #!/bin/bash if [ ! -f /var/lib/mysql/ibdata1 ]; then mysql_install_db /usr/bin/mysqld_safe & sleep 10s echo "GRANT ALL ON *.* TO admin@'%' IDENTIFIED BY 'changeme' WITH GRANT OPTION; FLUSH PRIVILEGES" | mysql killall mysqld sleep 10s fi /usr/bin/mysqld_safe
三、构建mysql镜像
# docker build -t zhengys/mysql .
四、查看镜像
[root@localhost ~]# docker p_w_picpaths REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE zhengys/mysql latest f58add96ecb7 About a minute ago 338.9 MB
六、基于新镜像建立mysql容器
[root@localhost ~]# mkdir /data/mysql -p [root@localhost ~]# docker run -d -p 3306:3306 -v /data/mysql:/var/lib/mysql zhengys/mysql 0112ba90e4a30a13e4f3af26f4a5bcd73e91ae3afa881a36fadd34cd953d0ada [root@localhost ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 0112ba90e4a3 zhengys/mysql:latest "/bin/bash /opt/star 4 seconds ago Up 3 seconds 0.0.0.0:3306->3306/tcp reverent_hawking [root@localhost ~]# ll /data/mysql/ total 28680 -rw-rw----. 1 103 106 18874368 Apr 25 17:46 ibdata1 -rw-rw----. 1 103 106 5242880 Apr 25 19:09 ib_logfile0 -rw-rw----. 1 103 106 5242880 Apr 25 17:45 ib_logfile1 drwx------. 2 103 root 4096 Apr 25 17:45 mysql drwx------. 2 103 106 4096 Apr 25 17:45 performance_schema
七、测试mysql容器
[root@localhost ~]# mysql -uadmin -p123456 -h192.168.0.104 -P 3306 -e 'show databases' +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | +--------------------+
或者提供一个登录mysql客户端脚本
#!/bin/sh TAG="mysql" CONTAINER_ID=$(docker ps | grep $TAG | awk '{print $1}') IP=$(docker inspect $CONTAINER_ID | python -c 'import json,sys;obj=json.load(sys.stdin);print obj[0]["NetworkSettings"]["IPAddress"]') mysql -u admin -p -h $IP
6、简化Docker和lxc
一、Lxc和Docker结构图
Linux = linux内核 + 用户空间(Lxc)
Lxc(Linux Container):linux容器 = Cgroup + Namespaces
Docker集装箱 = Lxc + p_w_picpaths
lxc功能包括资源管理和隔离机制。
资源管理:经过cgroup限制cpu和内存的使用
隔离机制:用户空间namespace都是独立的
LXC包集成了这些linux内核机制提供了一个用户空间容器对象,便是针对某一应用提供资源隔离和控制轻量级虚拟系统。
Docker对container的使用基本是创建在lxc基础之上的,然而lxc存在的问题是难以移动-难以经过标准化模板制做、重建、复制和移动container。
LXC依赖namespace来实现隔离性的。
让每一个容器都有自已的命名空间,确保不一样容器之间不会相互影响,让每一个容器成为拥有自已进程和网络空间的虚拟环境,都成为一个独立运行的单位。
此外,lxc由内核cgroup来对各个容器(进程)使用的系统资源作严格的限制。
算算时间,学习Docker也有半个月时间了,到如今为止给个人第一感受仍然是不习惯,或许是用传统虚拟化用习惯了,或许是自已对Docker研究过于肤浅,或许自已根本没有入门等等一些缘由,在没有接触到Docker以前自已玩过lxc,使用起来特别顺手,网上都说Docker自动化了lxc的管理过程,可以自动在线下载相应的发行版本rootfs
Docker的火热程度,使咱们作IT的不得不去深刻研究、学习
好吧!今天就先到这里,后续会继续更你们聊聊Docker技术.