无法使用 docker-compose 从 Tomcat Docker 容器访问主机

Question

我有一个 docker-compose 版本 1.25.0 和 Docker 版本 20.10.12。 我在 Ubuntu 21.04 上运行。 我有一个 Spring 引导程序作为 .war 文件，我在 tomcat 内部运行。 该程序在 docker 容器外运行良好，但是当我在 docker 容器内运行时，我无法在浏览器中访问它。

我的 Dockerfile 是这样的：

FROM tomcat:9-jdk8
ADD ./build/libs/studentLetter-1.0.2.war /usr/local/tomcat/webapps/
EXPOSE 8080
RUN mkdir -p /home/gmarsh/workdir
CMD ["catalina.sh", "run"]

我的 docker-compose.yml 文件包含以下内容：

version: '3.8'

services:
    app:
      build: ./
      image: wbsgrader-online-img
      ports:
        - 8080:8080
      extra_hosts:
        - dockerhost:$DOCKER_HOST
      network_mode: "host"

其中 DOCKER_HOST 在 my.profile 中被导出为 this

export DOCKER_HOST=`/sbin/ifconfig docker0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'`

我在终端输入

docker-compose up --build -d

output 是：

Building app
Step 1/4 : FROM tomcat:latest
 ---> fb5657adc892
Step 2/4 : ADD ./build/libs/studentLetter-1.0.2.war /usr/local/tomcat/webapps/
 ---> Using cache
 ---> 891060c813d6
Step 3/4 : EXPOSE 8080
 ---> Using cache
 ---> fbd16298db6c
Step 4/4 : CMD ["catalina.sh", "run"]
 ---> Using cache
 ---> 432a1484e8ae
Successfully built 432a1484e8ae
Successfully tagged wbsgrader-img:latest
Creating onlinewbsgrader_app_1 ... done

docker-compose 日志中的 output 是：

Attaching to onlinewbsgrader_app_1
app_1  | 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
app_1  | 31-Dec-2021 22:57:51.711 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version name:   Apache Tomcat/10.0.14
app_1  | 31-Dec-2021 22:57:51.716 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built:          Dec 2 2021 22:01:36 UTC
app_1  | 31-Dec-2021 22:57:51.717 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version number: 10.0.14.0
app_1  | 31-Dec-2021 22:57:51.717 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name:               Linux
app_1  | 31-Dec-2021 22:57:51.717 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version:            5.11.0-41-generic
app_1  | 31-Dec-2021 22:57:51.717 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture:          amd64
app_1  | 31-Dec-2021 22:57:51.718 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home:             /usr/local/openjdk-11
app_1  | 31-Dec-2021 22:57:51.718 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version:           11.0.13+8
app_1  | 31-Dec-2021 22:57:51.718 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor:            Oracle Corporation
app_1  | 31-Dec-2021 22:57:51.719 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE:         /usr/local/tomcat
app_1  | 31-Dec-2021 22:57:51.719 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME:         /usr/local/tomcat
app_1  | 31-Dec-2021 22:57:51.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.lang=ALL-UNNAMED
app_1  | 31-Dec-2021 22:57:51.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.io=ALL-UNNAMED
app_1  | 31-Dec-2021 22:57:51.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.util=ALL-UNNAMED
app_1  | 31-Dec-2021 22:57:51.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED
app_1  | 31-Dec-2021 22:57:51.736 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
app_1  | 31-Dec-2021 22:57:51.737 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties
app_1  | 31-Dec-2021 22:57:51.737 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
app_1  | 31-Dec-2021 22:57:51.737 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
app_1  | 31-Dec-2021 22:57:51.737 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
app_1  | 31-Dec-2021 22:57:51.738 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dorg.apache.catalina.security.SecurityListener.UMASK=0027
app_1  | 31-Dec-2021 22:57:51.738 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dignore.endorsed.dirs=
app_1  | 31-Dec-2021 22:57:51.738 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=/usr/local/tomcat
app_1  | 31-Dec-2021 22:57:51.739 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=/usr/local/tomcat
app_1  | 31-Dec-2021 22:57:51.739 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=/usr/local/tomcat/temp
app_1  | 31-Dec-2021 22:57:51.744 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded Apache Tomcat Native library [1.2.31] using APR version [1.7.0].
app_1  | 31-Dec-2021 22:57:51.744 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true], UDS [true].
app_1  | 31-Dec-2021 22:57:51.748 INFO [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL successfully initialized [OpenSSL 1.1.1k  25 Mar 2021]
app_1  | 31-Dec-2021 22:57:52.344 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
app_1  | 31-Dec-2021 22:57:52.382 INFO [main] org.apache.catalina.startup.Catalina.load Server initialization in [967] milliseconds
app_1  | 31-Dec-2021 22:57:52.463 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
app_1  | 31-Dec-2021 22:57:52.463 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet engine: [Apache Tomcat/10.0.14]
app_1  | 31-Dec-2021 22:57:52.484 INFO [main] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [/usr/local/tomcat/webapps/studentLetter-1.0.2.war]
app_1  | 31-Dec-2021 22:57:58.056 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.
app_1  | 31-Dec-2021 22:57:58.134 INFO [main] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [/usr/local/tomcat/webapps/studentLetter-1.0.2.war] has finished in [5,650] ms
app_1  | 31-Dec-2021 22:57:58.141 INFO [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
app_1  | 31-Dec-2021 22:57:58.153 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in [5770] milliseconds

正如它在日志中显示的那样，catalina 服务已启动，并且我的 program.war 文件已部署到 docker 容器内的 /usr/local/tomcat/webapps。

当我在浏览器地址栏中键入 http://localhost:8080/ 时，我收到 HTTP 状态 404 – 未找到错误。

当我输入

docker ps

我明白了：

CONTAINER ID   IMAGE           COMMAND             CREATED          STATUS          PORTS     NAMES
097a4da40100   wbsgrader-img   "catalina.sh run"   10 minutes ago   Up 10 minutes             onlinewbsgrader_app_1

请注意，显示器中缺少端口。 看起来端口绑定由于某种原因没有发生。

如何使用 docker-compose 使端口绑定工作并通过 localhost 获得浏览器访问权限？

Answer 1

如果您遇到404错误，则意味着您的端口实际上已暴露，但 Tomcat 无法在根上下文路径中找到应用程序。

在 Docker 和 Spring 引导的情况下，您应该按照某些步骤成功部署您的战争。

基本上，您需要：

• 在您的应用程序中提供SpringBootServletInitializer子类：

@SpringBootApplication
public class MyApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(MyApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

}

• Package 你的应用程序作为一个war文件。 例如，使用 Maven 提供以下配置：

<packaging>war</packaging>

• 如有必要，将 Tomcat 依赖项标记为provided ：

<dependencies>
    <!-- ... -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>
    <!-- ... -->
</dependencies>

Spring 引导文档中很好地描述了该过程。