Hi all,
AFAIK, Maven WAR overlays are supported - one just needs to prepare the corresponding pom.xml on their own. If all you need is to get your custom CAS war, a standard Maven build should be sufficient - we use this approach for years in the company I work for, and we haven't experienced any issue with it. (Also, I must admit I'm not a big fan of Gradle for many reasons, but that is for another story...)
If it helps, here is a "starter" pom.xml for building cas.war which you can deploy e.g. to Tomcat:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd ">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example.cas</groupId>
<artifactId>cas</artifactId>
<packaging>war</packaging>
<version>1.0.0-SNAPSHOT</version>
<properties>
<cas.version>6.6.10</cas.version>
<!-- also define properties like Java version for Maven compiler etc. -->
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apereo.cas</groupId>
<artifactId>cas-server-support-bom</artifactId>
<version>${cas.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apereo.cas</groupId>
<artifactId>cas-server-webapp</artifactId>
<version>${cas.version}</version>
<type>war</type>
<scope>runtime</scope>
</dependency>
<!-- ===== Optional CAS modules ===== -->
<!-- add dependencies as needed and as described in the CAS documentation -->
<!-- ===== Dependencies for compilation ===== -->
<!-- add CAS or other dependencies if you need to compile your own classes -->
</dependencies>
<build>
<finalName>cas</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
</project>
Regards
Petr