1、簡介python
Docker 是一個開源的應用容器引擎,讓開發者能夠打包他們的應用以及依賴包到一個可移植的容器中,而後發佈到任何流行的 Linux 機器上,也能夠實現虛擬化。容器是徹底使用沙箱機制,相互之間不會有任何接口(相似 iPhone 的 app)。幾乎沒有性能開銷,能夠很容易地在機器和數據中心中運行。mysql
Docker的理念:一個容器只運行一個服務linux
Docker官網口號包含了Build,Shipand Run Any App,Anywhere,即任何應用,均可以構建、發佈、運行於任何環境,將環境的影響因素降至最低,統一地掌控整個應用的生命週期。sql
Docker的官方文檔:http://docs.docker.com/docker
2、安裝json
一、安裝epel源 註釋:默認CentOS6.x提供的yum源裏沒有docker的安裝包,在這裏咱們藉助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、安裝docker # yum -y remove docker # yum install docker-io 三、啓動docker守護進程 # service docker start # chkconfig docker on 四、檢查docker是否已經正確安裝並運行 # docker info 五、查看docker的版本 # docker -v
3、命令參數ubuntu
一、docker命令幫助參數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、比較經常使用命令參數服務器
查看Docker的版本信息 # docker version 在Docker Hub上搜索一個指定鏡像 # docker search 在Docker Hub上搜索一個指定鏡像並至少有10顆星 # docker search -s 10 ubuntu 從一個Docker的註冊服務器上拉取一個鏡像或一個私有倉庫 # docker pull ubuntu 查看鏡像列表 # docker p_w_picpaths 在一個新的容器中運行一個命令 # docker run 移除一個或多個鏡像 # docker rmi 移除一個或多個容器 # docker rm 附着一個運行的容器 # docker attach 運行一個命令在一個運行的容器中 # docker exec 從一個Dockerfile文件中構建一個鏡像 # docker build 查看鏡像構建歷史 # docker history 查看容器更爲詳細的配置信息 # docker inspect 保存一個鏡像對歸檔tar中 # docker save 從一個歸檔tar中加載一個鏡像 # docker load 啓動、中止、重啓一個運行的容器 # docker start| stop| restart 殺掉一個正在運行的容器 # docker kill 額外補充 進入容器命令: docker attach:登錄到運行的容器中 docker exec:在宿主機上運行命令到容器內部,相似在打開一個容器的終端 docker nsenter:鏈接到容器,須要容器PID
4、建立ssh鏡像和鏡像打包網絡
一、從Docker Hub上下載ubuntu鏡像
[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、基於鏡像建立一個容器
[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、進入容器安裝ssh服務
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、構建一個ssh的鏡像
[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、基於新鏡像運行一個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、測試ssh容器是否可以正常鏈接
[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、鏡像持久化,俗稱鏡像打包
鏡像打包(Save)
[root@localhost ~]# docker save zhengyas/ubuntu > /root/sshd.tar
鏡像導入(Load)
實驗模擬 一、刪除此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、刪除sshd鏡像 [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、導入打包的鏡像 [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、基於Dockerfile來建立mysql鏡像
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服務啓動腳本文件
[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、構建mysql鏡像
# docker build -t zhengys/mysql .
四、查看鏡像
[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、基於新鏡像建立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、測試mysql容器
[root@localhost ~]# mysql -uadmin -p123456 -h192.168.0.104 -P 3306 -e 'show databases' +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | +--------------------+
或者提供一個登錄mysql客戶端腳本
#!/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、簡化Docker和lxc
一、Lxc和Docker結構圖
Linux = linux內核 + 用戶空間(Lxc)
Lxc(Linux Container):linux容器 = Cgroup + Namespaces
Docker集裝箱 = Lxc + p_w_picpaths
lxc功能包括資源管理和隔離機制。
資源管理:經過cgroup限制cpu和內存的使用
隔離機制:用戶空間namespace都是獨立的
LXC包集成了這些linux內核機制提供了一個用戶空間容器對象,便是針對某一應用提供資源隔離和控制輕量級虛擬系統。
Docker對container的使用基本是創建在lxc基礎之上的,然而lxc存在的問題是難以移動-難以經過標準化模板製做、重建、複製和移動container。
LXC依賴namespace來實現隔離性的。
讓每一個容器都有自已的命名空間,確保不一樣容器之間不會相互影響,讓每一個容器成爲擁有自已進程和網絡空間的虛擬環境,都成爲一個獨立運行的單位。
此外,lxc由內核cgroup來對各個容器(進程)使用的系統資源作嚴格的限制。
算算時間,學習Docker也有半個月時間了,到如今爲止給個人第一感受仍然是不習慣,或許是用傳統虛擬化用習慣了,或許是自已對Docker研究過於膚淺,或許自已根本沒有入門等等一些緣由,在沒有接觸到Docker以前自已玩過lxc,使用起來特別順手,網上都說Docker自動化了lxc的管理過程,可以自動在線下載相應的發行版本rootfs
Docker的火熱程度,使咱們作IT的不得不去深刻研究、學習
好吧!今天就先到這裏,後續會繼續更你們聊聊Docker技術.