add comments describing why we are doing certain things

Dockerfile

@@ -1,21 +1,18 @@
-# Use Linux-Alpine image
 FROM amazoncorretto:17.0.12-alpine
 
 RUN apk update && apk -U upgrade && rm -rf /var/cache/apk/*
 
 RUN adduser -S myLowPrivilegeUser
 USER myLowPrivilegeUser
 
-ARG JAR_LIB_FILE=./app/build/libs/app-all.jar
-
-# Create directory and switch to it
+# Set the workdir to a location that the running application can write to
+# which is in the myLowPrivilegeUser home folder because we are running as that user instead of root.
 WORKDIR /home/myLowPrivilegeUser/app/
 
-# Add application JAR to created folder
-COPY --chown=myLowPrivilegeUser ${JAR_LIB_FILE} /usr/local/bin/app.jar
+# Copy the jar file into /usr/local/bin/ because it seemingly needs to go to a location that any user can access.
+# If we put the jar file into the myLowPrivilegeUser's home directly, the container fails to run in Azure.
+COPY --chown=myLowPrivilegeUser ./app/build/libs/app-all.jar /usr/local/bin/app.jar
 
-# Run the api
 CMD ["java", "-jar", "/usr/local/bin/app.jar"]
 
-# Use port 8080
 EXPOSE 8080