Docker實踐 · Docker實踐

#### 一、Docker是什么 docker直譯為碼頭工人。當它成為一種技術時，做的也是碼頭工人的事。官網是這樣描述它的：“Docker是一個開發的平臺，用來為開發者和系統管理員構建、發布和運行分布式應用。”也就是說，如果把你的應用比喻為貨物，那么碼頭工人（Docker）就會迅速的用集裝箱將它們裝上船。快速、簡單而有效率。它是用Go語言寫的，是程序運行的“容器”（Linux containers），實現了應用級別的隔離（沙箱）。多個容器運行時互補影響，安全而穩定。我喜歡它的原因就是快速部署，安全運行，不污染我的系統。 #### 二、試用 Try it！官方提供一個互動的小教程，讓你很容易的了解Docker的基本用法，快去[試試](https://www.docker.com/tryit/)吧！ #### 三、安裝官方直接支持64位Linux系統安裝Docker，但如果想在32位系統中運行，有人也進行了一些嘗試，比如32Ubuntu下，參考[點擊打開鏈接](https://github.com/docker-32bit/ubuntu)。其他系統的安裝請參考[官網](https://docs.docker.com/installation/#installation)，下面說說我在Ubuntu14.04下的安裝。???????? 1.將鏡像加入到程序源中： ~~~ ~$?sudo?sh?-c?"echo?deb?http://mirror.yandex.ru/mirrors/docker/?docker?main?>?/etc/apt/sources.list.d/docker.list"?? ~~~ 2.接著update ~~~ $?sudo?apt-get?update?? ~~~ 3.如果報錯就fix掉它： ~~~ W:?GPG?error:?http://mirror.yandex.ru?docker?Release:?The?following?signatures?couldn't?be?verified?because?the?public?key?is?not?available:?NO_PUBKEY?D8576A8BA88D21E9?? ~~~ 解決此錯誤： ~~~ $?sudo?apt-key?adv?--keyserver?hkp://keyserver.ubuntu.com:80?--recv-keys?D8576A8BA88D21E9?? Executing:?gpg?--ignore-time-conflict?--no-options?--no-default-keyring?--secret-keyring?/tmp/tmp.RmJ1SUpsXX?--trustdb-name?/etc/apt/trustdb.gpg?--keyring?/etc/apt/trusted.gpg?--primary-keyring?/etc/apt/trusted.gpg?--keyserver?hkp://keyserver.ubuntu.com:80?--recv-keys?D8576A8BA88D21E9?? gpg:?requesting?key?A88D21E9?from?hkp?server?keyserver.ubuntu.com?? gpg:?key?A88D21E9:?public?key?"Docker?Release?Tool?(releasedocker)?"?imported?? gpg:?Total?number?processed:?1?? gpg:???????????????imported:?1??(RSA:?1)?? ~~~ 4.下載docker： ` $?sudo?apt-get?install?lxc-docker??` 靜靜的等待它下載完成吧。另外，這個命令也許會有幫助： ~~~ $ curl -sSL https://get.docker.com/ubuntu/ | sudo sh ~~~ #### 四、初步使用終端中輸入docker，打印出docker的命令列表： ~~~ Commands:?? ????attach????Attach?to?a?running?container?? ????build?????Build?an?image?from?a?Dockerfile?? ????commit????Create?a?new?image?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?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?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?image?or?a?repository?from?a?Docker?registry?server?? ????push??????Push?an?image?or?a?repository?to?a?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?on?the?Docker?Hub?? ????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?? ????unpause???Unpause?a?paused?container?? ????version???Show?the?Docker?version?information?? ????wait??????Block?until?a?container?stops,?then?print?its?exit?code?? ~~~ 接下來就可以嘗試使用這些命令了，不過在進行下一步之前，我們要先了解幾個概念。 #### 五、重要概念 1.image 鏡像鏡像就是一個只讀的模板。比如，一個鏡像可以包含一個完整的Ubuntu系統，并且安裝了apache。鏡像可以用來創建Docker容器。其他人制作好鏡像，我們可以拿過來輕松的使用。這就是吸引我的特性。 2.Docker container 容器 Docker用容器來運行應用。容器是從鏡像創建出來的實例（好有面向對象的感覺，類和對象），它可以被啟動、開始、停止和刪除。 3.倉庫這個好理解了，就是放鏡像的文件的場所。比如最大的公開倉庫是Docker Hub。 #### 六、幾個簡單的實踐 1.search 搜索倉庫中是否有wordpress這個博客鏡像，如下： ~~~ $?docker?search?wordpress?? NAME???????????????????????????????????DESCRIPTION?????????????????????????????????????STARS?????OFFICIAL???AUTOMATED?? wordpress??????????????????????????????The?WordPress?rich?content?management?syst...???185???????[OK]??? ~~~ 2.下載這個鏡像 ~~~ $?docker?pull?wordpress?? wordpress:latest:?The?image?you?are?pulling?has?been?verified?? ~~~ 3.查看自己的鏡像 ~~~ $?docker?images?? REPOSITORY???????????????TAG?????????????????IMAGE?ID????????????CREATED?????????????VIRTUAL?SIZE?? linc-wiki????????????????latest??????????????b5a1e34b01c2????????27?hours?ago????????689.7?MB?? ubuntu???????????????????latest??????????????5ba9dab47459????????5?days?ago??????????188.3?MB?? wordpress????????????????latest??????????????ecc04d6d638c????????6?days?ago??????????470?MB?? ~~~ 4.簡單的運行運行wordpress要進行mysql的配置，為了演示run，將ubuntu跑起來吧。 ~~~ $?docker?run?-it?ubuntu?/bin/bash?? root@46ff2a695ce1:/#?echo?"I?am?linc"?? I?am?linc?? ~~~ 至此，體驗結束。后續會有更加精彩的實踐等著我們，Docker，我們來了！參考： https://docs.docker.com/installation/ubuntulinux/ https://bitnami.com/stack/mediawiki https://docs.docker.com/userguide/ https://dockerpool.com/static/books/docker_practice http://zhumeng8337797.blog.163.com/blog/static/1007689142014524115743806/ http://www.cnblogs.com/imoing/p/dockervolumes.html https://github.com/docker/fig/issues/88