added hotswap/dcevm

Dockerfile

@@ -1,10 +1,7 @@
 
 FROM ubuntu:${ubuntu.version}
 
-RUN apt update
-RUN apt -y install openjdk-${java.majorVersion}-jdk
-RUN apt -y install tomcat${tomcat.majorVersion}
-
+# Configure the Apache Tomcat Catalina script
 ENV JAVA_MEMORY_INIT=128m
 ENV JAVA_MEMORY_MAX=512m
 ENV JAVA_HOME="/usr/lib/jvm/java-${java.majorVersion}-openjdk-amd64"
@@ -12,12 +9,23 @@ ENV CATALINA_HOME="/usr/share/tomcat${tomcat.majorVersion}"
 ENV CATALINA_BASE="/var/lib/tomcat${tomcat.majorVersion}"
 ENV CATALINA_OPTS=
 
+# Install the latest Apache Tomcat and its Java dependencies
+RUN apt update && apt -y install curl && \
+        apt -y install openjdk-${java.majorVersion}-jdk-headless && \
+        apt -y install openjdk-${java.majorVersion}-jre-dcevm && \
+        apt -y install tomcat${tomcat.majorVersion} && \
+        cd /var/lib/tomcat${tomcat.majorVersion}/lib && \
+        curl -OL https://github.com/HotswapProjects/HotswapAgent/releases/download/RELEASE-${hotswap.version}/hotswap-agent-${hotswap.version}.jar
+
+# Add our Docker container initialization script
 ADD docker-entrypoint.sh /usr/local/bin
 
-# This will give us dynamic injection points into the running webapps
+# Add our Apache Tomcat configuration
+#   This gives us dynamic injection points into the running webapps
 COPY tomcat-context.xml /etc/tomcat${tomcat.majorVersion}/context.xml
+COPY hotswap-agent.properties /var/lib/tomcat${tomcat.majorVersion}/lib
 
-# We need to create all possible mapped directories
+# Add directories for dynamic injection points
 RUN cd /var/lib/tomcat${tomcat.majorVersion} && \
 	rm -rf webapps/ROOT* && \
         mkdir dev && cd dev && \
@@ -25,8 +33,17 @@ RUN cd /var/lib/tomcat${tomcat.majorVersion} && \
         mkdir lib lib-extra1 lib-extra2 lib-extra3 lib-extra4 lib-extra5 lib-extra6 lib-extra7 && \
         mkdir web web-extra1 web-extra2 web-extra3 web-extra4 web-extra5 web-extra6 web-extra7
 
+# Listening for HTTP (not HTTPS) traffic
 EXPOSE 8080
+
+# Listening for Java debugger traffic
 EXPOSE 8000
 
+# Running as ROOT user for now
+#USER tomcat
+
+# Execute the Docker container initialization script
 ENTRYPOINT [ "/usr/local/bin/docker-entrypoint.sh" ]
+
+# Start the Apache Tomcat web container using the Catalina script
 CMD [ "/usr/share/tomcat${tomcat.majorVersion}/bin/catalina.sh", "run" ]