建置並執行 Java 應用程式的容器映像
在本單元中，您將建置並執行容器映像。 正如我們稍早所學的，映像的執行中執行個體是容器。
建置容器映像
既然您已成功建構 Dockerfile，您就可以指示 Docker 為您建置容器映像。
注意
確定您的 Docker 執行階段已設定為建置 Linux 容器。 這很重要，因為我們所使用的 Dockerfile 會參考 Linux 架構的容器映像 (JDK/JRE)。
docker build 是您將用來建置容器映像的命令。 您將使用 -t 引數來指定容器標籤，而 . 是 Docker 尋找 Dockerfile 的位置。 在 CLI 中執行下列命令：
docker build -t flightbookingsystemsample .
您會得到類似以下的輸出：
docker build -t flightbookingsystemsample .
Sending build context to Docker daemon 101.3MB
Step 1/11 : FROM maven:3.6.0-jdk-11-slim AS build
3.6.0-jdk-11-slim: Pulling from library/maven
27833a3ba0a5: Pull complete
16d944e3d00d: Pull complete
6aaf465b8930: Pull complete
0684138f4cb6: Pull complete
67c4e741e688: Pull complete
933857515267: Pull complete
4f31e2918c2c: Pull complete
70a0a987b087: Pull complete
8369c7ef3731: Pull complete
7a73ce905393: Pull complete
c702b567a1e8: Pull complete
Digest: sha256:4f0face24d2f79439a8fa394555b09be99c9ad537b9b19983fb8cc358818a42d
Status: Downloaded newer image for maven:3.6.0-jdk-11-slim
---> c7428be691f8
Step 2/11 : WORKDIR /build
---> Running in f1656ab15874
Removing intermediate container f1656ab15874
---> d9bfeb518c86
Step 3/11 : COPY pom.xml .
---> a60aab61d487
Step 4/11 : COPY src ./src
---> 049803b88a20
Step 5/11 : COPY web ./web
---> 8d98ddb1fbc3
Step 6/11 : RUN mvn clean package
---> Running in 71a462c5b3ad
[INFO] Scanning for projects...
...
[INFO] Packaging webapp
[INFO] Assembling webapp [FlightBookingSystemSample] in [/build/target/FlightBookingSystemSample-0.0.1-SNAPSHOT]
[INFO] Processing war project
[INFO] Copying webapp webResources [/build/web] to [/build/target/FlightBookingSystemSample-0.0.1-SNAPSHOT]
[INFO] Copying webapp resources [/build/src/main/webapp]
[INFO] Building war: /build/target/FlightBookingSystemSample-0.0.1-SNAPSHOT.war
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 26.811 s
[INFO] Finished at: 2021-10-09T01:58:31Z
[INFO] ------------------------------------------------------------------------
Removing intermediate container 71a462c5b3ad
---> 3d40f8a4f631
Step 7/11 : FROM tomcat:8.5.72-jre11-openjdk-slim
8.5.72-jre11-openjdk-slim: Pulling from library/tomcat
bd897bb914af: Pull complete
0cc7fec72146: Pull complete
14c358bab58a: Pull complete
c12f81e19ff2: Pull complete
89238a07057c: Pull complete
46896a83c0d8: Pull complete
15f6001bf0c8: Pull complete
34374d37175f: Pull complete
Digest: sha256:807efbd54faa7342c1f75f1466889148fda1f299b81dc40404312352a2086a5f
Status: Downloaded newer image for tomcat:8.5.72-jre11-openjdk-slim
---> 77903b2cfd74
Step 8/11 : COPY tomcat-users.xml /usr/local/tomcat/conf
---> c540464832e7
Step 9/11 : COPY --from=build /build/target/*.war /usr/local/tomcat/webapps/FlightBookingSystemSample.war
---> 6d1eb5d1568c
Step 10/11 : EXPOSE 8080
---> Running in 753385de3d77
Removing intermediate container 753385de3d77
---> f744382dd869
Step 11/11 : CMD ["catalina.sh", "run"]
---> Running in 58a822ee7a4a
Removing intermediate container 58a822ee7a4a
---> a0b73d3f3f91
Successfully built a0b73d3f3f91
Successfully tagged flightbookingsystemsample:latest
如您先前注意到的，Docker 已從您在上一個單元中撰寫的那些行執行指示。 每個指示都是循序的步驟。 再次重新執行 docker build 命令並注意步驟中的差異。 您會注意到 ---> Using cache 中尚未變更的層。 如果在重新執行 docker build 命令之前未進行應用程式變更，則您會注意到所有快取的層，因為二進位檔案未變更，而且可以從 Docker 快取中取得。 在最佳化容器映像，以及最佳化與建立映像時所花時間相關聯的計算成本時，這是一個重點資訊。
Docker 也可以顯示駐留的可用映像。 這有助於檢視可供執行的內容。 在 CLI 中執行下列命令：
docker image ls
您會得到類似以下的輸出：
docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
flightbookingsystemsample latest cda4f5b459f1 About an hour ago 268MB
執行容器映像
既然已成功建置容器映像，您就可以執行此容器映像。
docker run 是用來執行容器映像的命令。 -p ####:#### 引數將會在執行階段將 localhost HTTP (冒號前面的第一個連接埠) 流量轉送至容器 (冒號後面的第二個連接埠)。 請記住，從 Dockerfile 來看，Tomcat 應用程式伺服器正在連接埠 8080 上接聽 HTTP 流量，因此這是需要公開的容器連接埠。 最後，需要映像標籤 flightbookingsystemsample 才能指示 Docker 執行哪個映像。 在 CLI 中執行下列命令：
docker run -p 8080:8080 flightbookingsystemsample
您會得到類似以下的輸出：
docker run -p 8080:8080 flightbookingsystemsample
NOTE: Picked up JDK_JAVA_OPTIONS: --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.io=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.util.concurrent=ALL-UNNAMED --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
02-Aug-2021 20:50:22.682 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version name: Apache Tomcat/9.0.50
02-Aug-2021 20:50:22.687 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built: Jun 28 2021 08:46:44 UTC
02-Aug-2021 20:50:22.687 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version number: 9.0.50.0
02-Aug-2021 20:50:22.688 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name: Linux
02-Aug-2021 20:50:22.688 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version: 5.10.16.3-microsoft-standard-WSL2
02-Aug-2021 20:50:22.689 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture: amd64
02-Aug-2021 20:50:22.690 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home: /usr/local/openjdk-11
02-Aug-2021 20:50:22.694 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version: 11.0.12+7
02-Aug-2021 20:50:22.694 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor: Oracle Corporation
02-Aug-2021 20:50:22.695 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE: /usr/local/tomcat
02-Aug-2021 20:50:22.696 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME: /usr/local/tomcat
02-Aug-2021 20:50:22.729 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.lang=ALL-UNNAMED
02-Aug-2021 20:50:22.730 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.io=ALL-UNNAMED
02-Aug-2021 20:50:22.730 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.util=ALL-UNNAMED
02-Aug-2021 20:50:22.730 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED
02-Aug-2021 20:50:22.731 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
02-Aug-2021 20:50:22.731 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties
02-Aug-2021 20:50:22.733 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
02-Aug-2021 20:50:22.735 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
02-Aug-2021 20:50:22.735 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
02-Aug-2021 20:50:22.735 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dorg.apache.catalina.security.SecurityListener.UMASK=0027
02-Aug-2021 20:50:22.735 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dignore.endorsed.dirs=
02-Aug-2021 20:50:22.735 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=/usr/local/tomcat
02-Aug-2021 20:50:22.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=/usr/local/tomcat
02-Aug-2021 20:50:22.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=/usr/local/tomcat/temp
02-Aug-2021 20:50:22.762 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded Apache Tomcat Native library [1.2.30] using APR version [1.6.5].
02-Aug-2021 20:50:22.763 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true], UDS [true].
02-Aug-2021 20:50:22.763 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true]
02-Aug-2021 20:50:22.776 INFO [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL successfully initialized [OpenSSL 1.1.1d 10 Sep 2019]
02-Aug-2021 20:50:23.686 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
02-Aug-2021 20:50:23.777 INFO [main] org.apache.catalina.startup.Catalina.load Server initialization in [1697] milliseconds
02-Aug-2021 20:50:23.977 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
02-Aug-2021 20:50:23.978 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet engine: [Apache Tomcat/9.0.50]
02-Aug-2021 20:50:24.039 INFO [main] org.apache.catalina.startup.HostConfig.deployWAR Deploying web app archive [/usr/local/tomcat/webapps/FlightBookingSystemSample.war]
02-Aug-2021 20:50:27.164 INFO [main] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
02-Aug-2021 20:50:30.887 INFO [main] com.sun.xml.ws.server.MonitorBase.createRoot Metro monitoring rootname successfully set to: com.sun.metro:pp=/,type=WSEndpoint,name=/FlightBookingSystemSample-PriceAndSeats-PriceAndSeatsPort
02-Aug-2021 20:50:31.151 INFO [main] com.sun.xml.ws.transport.http.servlet.WSServletDelegate.<init> WSSERVLET14: JAX-WS servlet initializing
02-Aug-2021 20:50:32.662 INFO [main] com.sun.xml.ws.transport.http.servlet.WSServletContextListener.contextInitialized WSSERVLET12: JAX-WS context listener initializing
02-Aug-2021 20:50:32.663 INFO [main] com.sun.xml.ws.transport.http.servlet.WSServletContextListener.contextInitialized WSSERVLET12: JAX-WS context listener initializing
02-Aug-2021 20:50:32.735 INFO [main] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web app archive [/usr/local/tomcat/webapps/FlightBookingSystemSample.war] has finished in [8,695] ms
02-Aug-2021 20:50:32.746 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
02-Aug-2021 20:50:32.768 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in [8990] milliseconds
開啟瀏覽器視窗並造訪適用於航空公司預約的航班預訂系統登陸頁面，網址為 http://localhost:8080/FlightBookingSystemSample。
您應該看到下列內容：
您可以選擇性地使用來自 tomcat-users.xml 的任何使用者登入；例如 someuser@azure.com: password。
若要停止容器，請在 CLI 內按下 CTRL + c。