构建Dockerfile时Maven编译失败

Question

我有一个Springboot应用程序，我正在尝试对其进行dockerize，这是我的Dockerfile。

FROM openjdk:11-jre-slim as build
WORKDIR /app
COPY mvnw .
COPY .mvn .mvn
COPY pom.xml .
RUN ./mvnw dependency:go-offline -B
# Copy the project source
COPY src src
# Package the application
RUN ./mvnw package -DskipTests
RUN mkdir -p target/dependency && (cd target/dependency; jar -xf ../*.jar)
FROM openjdk:11-jre-slim
ARG DEPENDENCY=/app/target/dependency
COPY --from=build ${DEPENDENCY}/BOOT-INF/lib /app/lib
COPY --from=build ${DEPENDENCY}/META-INF /app/META-INF
COPY --from=build ${DEPENDENCY}/BOOT-INF/classes /app
ENTRYPOINT ["java","-cp","app:app/lib/*", Path to my main class]

当试图构建Docker镜像时，我会遇到编译错误，这是在下载了一堆依赖项后的特定步骤发生的，这需要一些时间。

RUN ./mvnw package -DskipTests

[INFO] Changes detected - recompiling the module!
[INFO] Compiling 38 source files to /app/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  11.804 s
[INFO] Finished at: 2022-08-29T08:07:50Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project xxx: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

我的pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.6</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.springbootreact</groupId>
<artifactId>xxx</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>xxxx</name>
<description>xxxx</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.3.0</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-rest-webmvc</artifactId>
<version>3.5.3</version>
</dependency>
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt</artifactId>
<version>0.9.1</version>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.7</version>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

我尝试过使用许多jdk映像，但似乎仍然出现了错误，我尝试过谷歌搜索，大多数问题都是由与IDE和java路径变量有关的问题引起的，但我不知道如何在我的情况下修复这个错误。

Answer 1

错误本身会给出答案。尝试将图像切换到maven:3.8.6-openjdk-11。使用maven映像，您也不需要复制maven包装器。

我建议您在不同的env(可能是docker阶段(中构建JAR。构建JDK后，只将其复制到最终版本映像中。

Answer 2

如错误消息所示：

此环境中未提供编译器。

您的容器中只有一个JRE，它不包括编译器：

FROM openjdk:11-jre-slim

使用带有JDK 的容器