在Docker容器中部署Web應用
本文直接講解如何在Docker容器中實戰部署一個Web應用程式,關於Docker相關的概念和如何安裝Docker請參考相關資料完成。
第一步:工具準備
演示如何在Docker容器中部署一個Java Web應用程式,需要準備的軟體工具包括:jre,tomcat和webapp應用。另外,為了實現在容器啟動時自動啟動webapp,需要編寫一個指令碼工具完成該工作。
如何在tomcat中部署webapp,請參考:
jre1.8.0_31.tar.gz // 可以選擇其他版本
apache-tomcat-6.0.35.tar.gz // 可以選擇其他版本
MyWeb.war // 自己寫一個web應用即可,才發現csdn不允許上傳附件
start_tomcat.sh
第二步:製作映象
通過編寫Dockerfile的方式製作映象。
需要在Dockerfile中完成如下幾項工作:
(1)安裝jre
(2)安裝tomcat,並完成在tomcat中部署web應用的基本配置(為實現此功能:在製作映象之前直接先完成tomcat的基礎配置,然後直接拷貝到映象中即可)。
(3)對外開發8080埠(具體的埠值可以根據實際Tomcat配置引數為準)。
$mkdir docker
$cd docker
$mkdir webapps
$cp jre1.8.0_31.tar.gz .
$tar xzvf jre1.8.0_31.tar.gz
$cp apache-tomcat-6.0.35.tar.gz
$tar xzvf apache-tomcat-6.0.35.tar.gz
$cp MyWeb.war ./webapps/
$vim apache-tomcat-6.0.35/conf/server.xml
編輯tomcat配置檔案:server.xml,在<Host>節點中新增如下配置:<Context path="myweb"docBase="/webapps/MyWeb.war" reloadable="false"workDir="/tomcat_work"/>,配置片段如下所示:
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
<!-- SingleSignOn valve, shareauthentication between web applications
Documentation at:/docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn"/>
-->
<!-- Access log processes all example.
Documentation at:/docs/config/valve.html -->
<!--
<ValveclassName="org.apache.catalina.valves.AccessLogValve"directory="logs"
prefix="localhost_access_log." suffix=".txt"pattern="common" resolveHosts="false"/>
-->
<Contextpath="/myweb"docBase="/webapps/MyWeb.war"reloadable="false"workDir="/tomcat_work"/>
</Host>
$vim start_tomcat.sh
#!/bin/bash
#Date: 2015/02/02
#Desc:
# Start tomcat with docker containerstart.
echo "Start Tomcat ..."
# Export java path
export PATH=$PATH:/usr/local/java/bin
# Display container ipaddress
ifconfig
# Start tomcat
bash /usr/local/tomcat/bin/catalina.sh run
注意:啟動tomcat時必須通過$TOMCAT_HOME/bin/catalina.sh實現,不能使用$TOMCAT_HOME/bin/startup.sh啟動,否則指令碼執行後容器立刻就退出了。
編寫Dockerfile
#Build java web app container image
FROM docker.cn/docker/ubuntu:14.04
MAINTAINER chenchanghui<nuccch2010.163.com>
#Make java and tomcat install directory
RUN mkdir /usr/local/java
RUN mkdir /usr/local/tomcat
#Copy jre and tomcat into image
ADD jre1.8.0_31 /usr/local/java/
ADD apache-tomcat-6.0.35 /usr/local/tomcat/
ADD start_tomcat.sh start_tomcat.sh
#Expose http port
EXPOSE 8080
建立映象
$sudo docker build -t=”ubuntu/myweb:tomcat”.
Sendingbuild context to Docker daemon 270.6 MB
Sendingbuild context to Docker daemon
Step 0 :FROM docker.cn/docker/ubuntu:14.04
---> b39b81afc8ca
Step 1 :MAINTAINER chenchanghui <nuccch2010.163.com>
---> Running in cd9ba3324dae
---> ab45c422bdf5
Removingintermediate container cd9ba3324dae
Step 2 :RUN mkdir /usr/local/java
---> Running in f640de521691
---> bd94048cb633
Removingintermediate container f640de521691
Step 3 :RUN mkdir /usr/local/tomcat
---> Running in de4a392ec89d
---> 956ac99b8bec
Removingintermediate container de4a392ec89d
Step 4 :ADD jre1.8.0_31 /usr/local/java/
---> e3181a61f635
Removingintermediate container b69c147f28fe
Step 5 :ADD apache-tomcat-6.0.35 /usr/local/tomcat/
---> 9169a4ab9a80
Removingintermediate container c190162d7a5c
Step 6 :ADD start_tomcat.sh start_tomcat.sh
---> cf61f83dc0b0
Removingintermediate container 3f10c2a9e374
Step 7 :EXPOSE 8080
--->abea02c999a2
Removingintermediate container a3841acba123
Successfullybuilt abea02c999a2
第三部:啟動容器
webapp通過資料卷掛在到容器中進行部署,不需要拷貝到映象中。
$sudo docker run -t -i --name tomcat –v /home/$username/docker/webapps:/webapps/
ubuntu/myweb:tomcat /bin/bash/start_tomcat.sh
Start Tomcat ...
eth0 Link encap:Ethernet HWaddr02:42:ac:11:00:0c
inet addr:172.17.0.12 Bcast:0.0.0.0 Mask:255.255.0.0
……..
Feb 02, 2015 1:38:42 PMorg.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Nativelibrary which allows optimal performance in production environments was notfound on the java.library.path:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
Feb 02, 2015 1:38:42 PMorg.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 onhttp-8080
Feb 02, 2015 1:38:42 PMorg.apache.catalina.startup.Catalina load
INFO: Initialization processed in 788 ms
Feb 02, 2015 1:38:42 PMorg.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Feb 02, 2015 1:38:42 PM org.apache.catalina.core.StandardEnginestart
INFO: Starting Servlet Engine: ApacheTomcat/6.0.35
Feb 02, 2015 1:38:42 PMorg.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directorymanager
Feb 02, 2015 1:38:42 PM org.apache.catalina.startup.HostConfigdeployDirectory
INFO: Deploying web application directorydocs
Feb 02, 2015 1:38:42 PMorg.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directoryROOT
Feb 02, 2015 1:38:42 PM org.apache.catalina.startup.HostConfigdeployDirectory
INFO: Deploying web application directoryexamples
Feb 02, 2015 1:38:43 PMorg.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directoryhost-manager
Feb 02, 2015 1:38:43 PM org.apache.coyote.http11.Http11Protocolstart
INFO: Starting Coyote HTTP/1.1 on http-8080
Feb 02, 2015 1:38:43 PMorg.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Feb 02, 2015 1:38:43 PMorg.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/27 config=null
Feb 02, 2015 1:38:43 PMorg.apache.catalina.startup.Catalina start
INFO: Server startup in 842 ms
如日誌所示,Docker容器已經啟動,並且其中安裝的tomcat已經成功啟動。
小技巧:啟動容器時帶引數-t -i和不帶引數的區別:帶引數-t -i時可以通過Ctrl+C停止容器執行,不帶引數-t -i啟動時,停止容器只能通過命令:$sudo docker stop $containerid實現。