Spring boot maven plugin - BOOT-INF directory causing AWS Lambda application to fail - maven

Question

There has been a change in the generated package structure (if you extract the uber jar file) in SpringBoot 2.1.0.RELEASE.
The 1.5.9.RELEASE jar file has com, lib, META-INF, and org directories
2.1.0.RELEASE has a BOOT-INF, META-INF and org directories
Basically from 2.0.0.RELEASE onwards - all the classes and libs are in the BOOT-INF directory.
Due to this - when you try to run a Spring Boot project on Amazon Lambda - it says that there is a jar not found as it cannot read the new Spring Boot Uber jar structure
My question:
Is it possible in the newer versions of the Spring Boot Maven Plugin, to generate the uber jar to be the same structure as in version 1.5.9.RELEASE?
I tried the maven-shade-plugin - but that leads to other issues. Any help is appreciated.
Reference link from StackOverflow: Spring Boot Maven Plugin - No BOOT-INF directory

Answer 1

This snippet of maven plugin XML did the trick for me:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>3.1.1</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
<includeScope>runtime</includeScope>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
<executions>
<execution>
<id>zip-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<finalName>${project.artifactId}-${project.version}</finalName>
<descriptors>
<descriptor>src${file.separator}assembly${file.separator}bin.xml</descriptor>
</descriptors>
<attach>false</attach>
</configuration>
</execution>
</executions>
</plugin>
In addition, you will need an assembly/bin.xml file with the following contents:
<assembly xmlns="http://maven.apache.org/ASSEMBLY/2.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/ASSEMBLY/2.0.0 http://maven.apache.org/xsd/assembly-2.0.0.xsd">
<id>lambda-package</id>
<formats>
<format>zip</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<fileSets>
<!-- copy runtime dependencies with some exclusions -->
<fileSet>
<directory>${project.build.directory}${file.separator}lib</directory>
<outputDirectory>lib</outputDirectory>
<excludes>
<exclude>tomcat-embed*</exclude>
</excludes>
</fileSet>
<!-- copy all classes -->
<fileSet>
<directory>${project.build.directory}${file.separator}classes</directory>
<includes>
<include>**</include>
</includes>
<outputDirectory>${file.separator}</outputDirectory>
</fileSet>
</fileSets>
</assembly>
Note that you will have to use the generated .zip file rather than the .jar file.
A full working example of using Spring Boot 2 with Lambda is available from awslabs: https://github.com/awslabs/aws-serverless-java-container/tree/master/samples/springboot2/pet-store