$ git clone https://github.com/apereo/cas-overlay-template

$ git checkout 5.1

We want JSON service registry, google auth and ldap support
Diff for adding our extra dependencies to pom.xml

$ git diff pom.xml
diff --git a/pom.xml b/pom.xml
index 126dc7c..51e35f0 100755
--- a/pom.xml
+++ b/pom.xml
@@ -66,13 +66,43 @@
             <type>war</type>
             <scope>runtime</scope>
         </dependency>
+       <dependency>
+         <groupId>org.apereo.cas</groupId>
+         <artifactId>cas-server-webapp-config-security</artifactId>
+         <version>${cas.version}</version>
+       </dependency>
+       <dependency>
+         <groupId>org.apereo.cas</groupId>
+         <artifactId>cas-server-support-jdbc-drivers</artifactId>
+         <version>${cas.version}</version>
+       </dependency>
+        <dependency>
+           <groupId>org.apereo.cas</groupId>
+           <artifactId>cas-server-support-json-service-registry</artifactId>
+           <version>${cas.version}</version>
+       </dependency>
+       <dependency>
+           <groupId>org.apereo.cas</groupId>
+           <artifactId>cas-server-support-gauth</artifactId>
+           <version>${cas.version}</version>
+       </dependency>
+       <dependency>
+         <groupId>org.apereo.cas</groupId>
+         <artifactId>cas-server-support-gauth-jpa</artifactId>
+         <version>${cas.version}</version>
+       </dependency>
+       <dependency>
+           <groupId>org.apereo.cas</groupId>
+           <artifactId>cas-server-support-ldap</artifactId>
+           <version>${cas.version}</version>
+       </dependency>
     </dependencies>
 
     <properties>
         <cas.version>5.1.9</cas.version>
         <springboot.version>1.5.3.RELEASE</springboot.version>
         <!-- app.server could be -jetty, -undertow, -tomcat, or blank if you plan to provide appserver -->
-        <app.server>-tomcat</app.server> 
+        <app.server></app.server>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

asuadmin@wrkm-guacamole:~/cas-overlay-template$ bash build.sh package
root@wrkm-guacamole:/home/asuadmin/cas-overlay-template# cp target/cas.war /var/lib/tomcat8/webapps/

root@wrkm-guacamole:~# mkdir -p /etc/cas/logs root@wrkm-guacamole:~# chown tomcat8 /etc/cas/logs/

We can do this since we use HTTPS on the reverse proxy to localhost:8080

root@wrkm-guacamole:/etc/tomcat8# diff -u /etc/tomcat8/server.xml-org /etc/tomcat8/server.xml
--- /etc/tomcat8/server.xml-org 2017-06-21 13:36:46.000000000 +0200
+++ /etc/tomcat8/server.xml     2017-11-05 21:08:49.050114344 +0100
@@ -68,7 +68,7 @@
     -->
     <Connector port="8080" protocol="HTTP/1.1"
                connectionTimeout="20000"
-               redirectPort="8443" />
+               secure="true" />
     <!-- A "Connector" using the shared thread pool-->
     <!--
     <Connector executor="tomcatThreadPool"

In /etc/default/tomcat8
JAVA_OPTS=“-Djava.awt.headless=true -XX:+UseConcMarkSweepGC -Djava.security.egd=file:/dev/./urandom -Djava.security.auth.login.config=file:/etc/cas/config/jaas.config -Djava.security.krb5.conf=/etc/krb5.conf”

root@wrkm-guacamole:/etc/apache2/conf-available# cat cas-rproxy.conf

<Location /cas/>
   SSLRequireSSL
   Order allow,deny
   Allow from all
   ProxyPass http://localhost:8080/cas/
   ProxyPassReverse http://localhost:8080/cas/
</Location>

To just build the standard default build

$ git clone https://github.com/apereo/cas-overlay-template cas-overlay-template-6.3.x
$ git checkout origin/6.3 -b wrkm-6.3
 
$ ./gradlew build
 
[...]
 
$ ls -l build/libs/cas.war 
-rw-r--r-- 1 xxx xxx 101063231 Mar 16 09:18 build/libs/cas.war

Add our dependencies, and choose to run in the Debian tomcat container

diff --git a/build.gradle b/build.gradle
index 89791ab..3d646b4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -82,6 +82,14 @@ dependencies {
     }
     // CAS dependencies/modules may be listed here statically...
     implementation "org.apereo.cas:cas-server-webapp-init:${casServerVersion}"
+    implementation "org.apereo.cas:cas-server-support-json-service-registry:${casServerVersion}"
+    implementation "org.apereo.cas:cas-server-support-jpa-ticket-registry:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-jdbc-drivers:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-gauth:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-gauth-jpa:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-ldap:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-reports:${project.'cas.version'}"
+    implementation "org.apereo.cas:cas-server-support-oauth-webflow:${project.'cas.version'}"
 }
 
 tasks.findByName("jibDockerBuild")
diff --git a/gradle.properties b/gradle.properties
index cd77ab2..4c0e900 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -4,7 +4,7 @@ springBootVersion=2.3.7.RELEASE
 
 # Use -jetty, -undertow to other containers
 # Or blank if you want to deploy to an external container
-appServer=-tomcat
+appServer=
 executable=false
 
 tomcatVersion=9.0.43

Extract the War to get hold of the files that may need to be modified

$ ./gradlew explodeWar

Then copy and modify files like so:

cp build/cas-resources/templates/fragments/footer.html src/main/resources/templates/fragments/

Added to the server.xml - in addition to previous noted changes

<!-- Remote IP Valve - to parse the X-Forwarded-For type headers -->
<Valve className="org.apache.catalina.valves.RemoteIpValve" />