Improve Dockerfile example

examples/docker/Dockerfile

@@ -1,4 +1,4 @@
-# Start form the Official Lightstramer Server image
+# Start from the Official Lightstramer Server image
 FROM lightstreamer
 
 # The Kafka Connector project version
@@ -10,21 +10,26 @@ ENV DEPLOY_DIR=/lightstreamer/adapters/${KAFKA_CONNECTOR_NAME}
 
 # Copy the distribution package 
 COPY tmp/${KAFKA_CONNECTOR_ZIP} /tmp/${KAFKA_CONNECTOR_ZIP}
-# Copy custom resources
+
+# Copy the custom resources
 COPY resources /tmp/resources
 
-# Switch to the root user to allow OS updates.
+# Switch to the root user to allow sytem updates.
 USER root
 RUN apt-get -y update; \
-    apt-get install -y unzip; \
-    # Unzip the distribution package into to Lightstreamer's adapters fodler.
+    apt-get install -y unzip rsync; \
+    # Unzip the distribution package into the Lightstreamer's adapters fodler
     unzip /tmp/${KAFKA_CONNECTOR_ZIP} -d /lightstreamer/adapters; \
     # Set the env prefix for referencing environment variables in adapters.xml
     sed -i -e 's/env_prefix=""/env_prefix="env."/' /lightstreamer/conf/lightstreamer_conf.xml; \
-    # Copy the custom resources
-    cp /tmp/resources/* ${DEPLOY_DIR}; \
+    # Copy the custom resources into the Lightstreamer's adapters fodler
+    rsync -av --exclude=README.md /tmp/resources/* ${DEPLOY_DIR}; \
     # Fix ownership
-    chown lightstreamer:lightstreamer -R ${DEPLOY_DIR}
+    chown lightstreamer:lightstreamer -R ${DEPLOY_DIR}; \
+    # Clean up
+    rm -fr /tmp/${KAFKA_CONNECTOR_ZIP} /tmp/resources; \
+    apt-get remove -y unzip rsync; \
+    rm -rf /var/lib/apt/lists/*
 
 # Restore the original Lightstreamer user
 USER lightstreamer