From d2a33a028dac3b7a1c73b1577528c8701b9fb8b7 Mon Sep 17 00:00:00 2001
From: Brian Long <brian@inteligr8.com>
Date: Mon, 15 Mar 2021 14:37:43 -0400
Subject: [PATCH] added hotswap/dcevm

---
 Dockerfile               | 29 +++++++++++++++++++++++------
 hotswap-agent.properties |  6 +++---
 pom.xml                  | 28 +++++++++++++++++++++++-----
 3 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 6420be1..e5e69d8 100644
--- a/Dockerfile
+++ b/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" ]
diff --git a/hotswap-agent.properties b/hotswap-agent.properties
index 558b0a2..c3992ec 100644
--- a/hotswap-agent.properties
+++ b/hotswap-agent.properties
@@ -19,14 +19,14 @@ extraClasspath=/var/lib/tomcat9/dev/classes
 # replacements of resources in a building step (maven filtering resource option).
 # This setting will leave i.e. src/target/classes as default source for resources, but after the resource is modified
 # in src/main/resources, the new changed resource is served instead.
-watchResources=
+watchResources=/var/lib/tomcat9/dev/classes
 
 # Load static web resources from different directory.
 #
 # This setting is dependent on application server plugin(Jetty, Tomcat, ...).
 # Jboss and Glassfish are not yet supported.
 # Use this setting to set to serve resources from source directory directly (e.g. src/main/webapp).
-webappDir=
+webappDir=/var/lib/tomcat9/dev/web
 
 
 # Comma separated list of disabled plugins
@@ -54,7 +54,7 @@ autoHotswap=true
 #
 # You need to specify JPDA port at startup
 # <pre>java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8000</pre>
-# autoHotswap.port=8000
+autoHotswap.port=8000
 
 # Enables debugging in OsgiEquinox
 # osgiEquinox.debugMode=true
diff --git a/pom.xml b/pom.xml
index 8319877..5af81c5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -3,21 +3,35 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.inteligr8</groupId>
     <artifactId>tomcat-rad</artifactId>
-    <version>9-1.1</version>
+    <version>9-1.2</version>
     <name>Apache Tomcat for Rapid Application Development</name>
     <packaging>pom</packaging>
 
     <properties>
+        <!-- The release version of Ubuntu to use as the base -->
+        <!-- This really only impacts what versions may be available for other components -->
         <ubuntu.version>20.04</ubuntu.version>
-        <java.majorVersion>11</java.majorVersion>
+
+        <!-- The version of the hotswap agent to use -->
+        <hotswap.version>1.4.1</hotswap.version>
+
+        <!-- The major version of Apache Tomcat to serve as the basis of this Docker image -->
         <tomcat.majorVersion>9</tomcat.majorVersion>
+
+        <!-- The major version of Java to use for executing Apache Tomcat -->
+        <!-- This version must have both the JDK/Headless and DCEVM packages -->
+        <java.majorVersion>11</java.majorVersion>
+
+        <!-- The Docker image meta-data for pushing the build -->
         <image.name>inteligr8/${project.artifactId}</image.name>
         <image.tag>${project.version}</image.tag>
         <image.registry>docker.inteligr8.com</image.registry>
+        <docker.noCache>true</docker.noCache>
     </properties>
 
     <build>
         <plugins>
+            <!-- This plugin build and pushes the Docker image -->
             <plugin>
                 <groupId>io.fabric8</groupId>
                 <artifactId>fabric8-maven-plugin</artifactId>
@@ -30,13 +44,17 @@
                         </image>
                     </images>
                     <contextDir>${basedir}</contextDir>
+                    <buildStrategy>docker</buildStrategy>
+                    <verbose>true</verbose>
                 </configuration>
                 <executions>
+                    <!-- This execution builds the Docker image -->
                     <execution>
                         <id>docker-build</id>
                         <phase>package</phase>
                         <goals><goal>build</goal></goals>
                     </execution>
+                    <!-- This execution pushes the built Docker image to the configured Docker Registry -->
                     <execution>
                         <id>docker-push</id>
                         <phase>deploy</phase>
@@ -44,6 +62,7 @@
                     </execution>
                 </executions>
             </plugin>
+            <!-- This plugin prevents the project from deploying to the Maven Repository, as it is pointless -->
             <plugin>
             	<artifactId>maven-deploy-plugin</artifactId>
             	<configuration>
@@ -55,10 +74,9 @@
 
     <profiles>
         <profile>
-            <id>use-local-docker</id>
+            <id>no-docker</id>
             <properties>
-                <fabric8.build.jib>false</fabric8.build.jib>
-                <fabric8.build.strategy>docker</fabric8.build.strategy>
+                <fabric8.build.jib>true</fabric8.build.jib>
             </properties>
         </profile>
     </profiles>