Explode WAR instead of working on exploded WAR directory for Maven

Explode the WAR file rather than using this directory. The contents of the final WAR may be different from this directory (it’s possible to include or exclude files when packaging a WAR. Also the exploded WAR directory is configurable with <webappDirectory> and may not be at build.getFinalName().

https://github.com/GoogleContainerTools/jib/pull/1068/files#r221696396

[TadCordle]

@edrandall @joelhandwell @Daiki-Kawanuma @cessien @kurczynski @CauchyPeano We’ve released v1.7.0 with this fix!

[edrandall]

The following maven ‘hack’ seems to provide a crude workaround, by extracting the META-INF/ from the war into the working dir after packaging but before the Jib goal executes:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-dependency-plugin</artifactId>
  <version>3.1.1</version
  <executions>
    <execution>
      <id>unpack-meta-inf</id>
      <phase>package</phase>
      <goals>
        <goal>unpack</goal>
      </goals>
      <configuration>
        <artifactItems>
          <artifactItem>
            <groupId>${project.groupId}</groupId>
            <artifactId>${project.artifactId}</artifactId>
            <version>${project.version}</version>
            <type>war</type>
            <overWrite>true</overWrite>
            <outputDirectory>${project.build.directory}/${project.build.finalName}</outputDirectory>
            <includes>META-INF/</includes>
          </artifactItem>
        </artifactItems>
      </configuration>
    </execution>
  </executions>
</plugin>