Question

我正在尝试为基于maven的Java项目设置多阶段dockerfile。到目前为止，这是我正在使用的：

### STAGE 1: Build ###
FROM maven:3.6.1-jdk-8 as build

WORKDIR /usr/src/app

# Install app dependencies
COPY pom.xml .
RUN mvn dependency:go-offline

# Bundle app source
COPY src src
RUN mvn package

### STAGE 2: Production Environment ###
FROM jboss/wildfly:17.0.0.Final

COPY --from=build /usr/src/app/target/Appname.war /opt/jboss/wildfly/standalone/deployments/Appname.war

RUN /opt/jboss/wildfly/bin/add-user.sh admin admin123 --silent
CMD ["/opt/jboss/wildfly/bin/standalone.sh", "-b", "0.0.0.0", "-bmanagement", "0.0.0.0"]

问题与mvn命令有关。我看到mvn dependency:go-offline下载了一些依赖项，这很棒。但是随后mvn package下载了更多软件包。为什么？我如何执行两个步骤：

用于解决和下载所有依赖项的一个
一个用于编译源代码并创建.war文件的

编辑

使用mvn package -o，找不到以下软件包：

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:2.6:resources (default-resources) on project monolith: Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:2.6:resources failed: Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved: The following artifacts could not be resolved: org.apache.maven:maven-profile:jar:2.0.6, org.apache.maven:maven-repository-metadata:jar:2.0.6, org.apache.maven:maven-plugin-registry:jar:2.0.6, classworlds:classworlds:jar:1.1-alpha-2: Cannot access central (https://repo.maven.apache.org/maven2) in offline mode and the artifact org.apache.maven:maven-profile:jar:2.0.6 has not been downloaded from it before. -> [Help 1]

我认为它与pom.xml中的build插件有关。有什么想法吗？

<build>
    <finalName>Monolith</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
        <plugin>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.2.3</version>
            <!--<configuration>-->
                <!--<webXml>src\main\webapp\WEB-INF\web.xml</webXml>-->
            <!--</configuration>-->
        </plugin>
    </plugins>
</build>

Answer 1

您最有可能受到MDEP-82 go-offline / resolve-plugins does not resolve all plugin dependencies错误的影响，该错误目前尚未解决。

根据MDEP-82问题中的this comment，可以通过指定maven-dependency-plugin版本而不是使用默认版本来解决此问题：

然后明确定义用于脱机的maven-dependency-plugin版本，而不依赖于Maven内部定义的默认版本：

mvn -s settings.xml org.apache.maven.plugins:maven-dependency-plugin:2.8:go-offline

Answer 2

maven依赖插件有一些限制，因此不会下载所有依赖。当您在本地工作时，这通常可以解决，因为一个mvn package命令就可以解决问题。

但这不适用于在Docker容器中运行的Maven。经过大量搜索，今天我偶然发现了go-offline-maven-plugin。我在用于测试的小项目上进行了尝试，并且成功了。

这是将其包含在pom.xml中的方法：

<!-- ... -->
<build>
    <plugins>
        <plugin>
            <groupId>de.qaware.maven</groupId>
            <artifactId>go-offline-maven-plugin</artifactId>
            <version>1.2.1</version>
            <configuration>
                <dynamicDependencies>
                    <DynamicDependency>
                        <groupId>org.apache.maven.surefire</groupId>
                        <artifactId>surefire-junit4</artifactId>
                        <version>2.20.1</version>
                        <repositoryType>PLUGIN</repositoryType>
                    </DynamicDependency>
                </dynamicDependencies>
            </configuration>
        </plugin>
        <!-- ... -->
    </plugins>
    <!-- ... -->
</build>
<!-- ... -->

dynamicDependencies是依赖项，在任何pom.xml中都没有，但是在插件中进行了硬编码。最常见的情况是surefire插件，该插件会根据您的测试（例如JUnit4 / 5，TestNG等）加载所需的依赖项。

最后，您需要从Dockerfile运行此插件。这应该起作用：

### STAGE 1: Build ###
FROM maven:3.6.1-jdk-8 as build

WORKDIR /usr/src/app

# Install app dependencies
COPY pom.xml .
RUN mvn -e -B de.qaware.maven:go-offline-maven-plugin:resolve-dependencies

# Bundle app source
COPY src src
RUN mvn -o -e -B package

### STAGE 2: Production Environment ###
FROM jboss/wildfly:17.0.0.Final

COPY --from=build /usr/src/app/target/Appname.war /opt/jboss/wildfly/standalone/deployments/Appname.war

RUN /opt/jboss/wildfly/bin/add-user.sh admin admin123 --silent
CMD ["/opt/jboss/wildfly/bin/standalone.sh", "-b", "0.0.0.0", "-bmanagement", "0.0.0.0"]

Docker多阶段Maven构建拆分依赖关系解析和编译

编辑

2 个答案: