Fix Dockerfile for k8s mvnw Not Found Error , Optimize Image Size with Multi-Stage Build and SERVER_HOST

Author: MingShyanWei

k8s/docker/Dockerfile

@@ -1,27 +1,49 @@
-FROM eclipse-temurin:17-jdk
+# Build Stage
+FROM eclipse-temurin:17-jdk AS build
 MAINTAINER daynnnnn
 
+# Setting environment variables
 ENV LANG=C.UTF-8 LC_ALL=C.UTF-8
 
+# Arguments for database configuration
 ARG DB_HOST
 ARG DB_USERNAME
 ARG DB_PASSWORD
 ARG DB_DATABASE
 ARG DB_PORT
 
+# Set the working directory for the build stage
 WORKDIR /code
 
+# Copy project files to the build stage
 ADD /src /code/src
 ADD /website /code/website
 ADD /pom.xml /code/pom.xml
+ADD mvnw /code/mvnw
+ADD .mvn /code/.mvn
 
+# Replace placeholders in pom.xml with actual environment values
 RUN sed -i 's|${db.ip}|${env.DB_HOST}|g' pom.xml
 RUN sed -i 's|${db.port}|${env.DB_PORT}|g' pom.xml
 RUN sed -i 's|${db.user}|${env.DB_USERNAME}|g' pom.xml
 RUN sed -i 's|${db.password}|${env.DB_PASSWORD}|g' pom.xml
 RUN sed -i 's|${db.schema}|${env.DB_DATABASE}|g' pom.xml
+RUN sed -i 's|${server.host}|${env.SERVER_HOST}|g' pom.xml
 
+# Make the Maven wrapper executable
+RUN chmod +x mvnw
+
+# Build the project
 RUN ./mvnw clean package -Pkubernetes -Djdk.tls.client.protocols="TLSv1,TLSv1.1,TLSv1.2"
 
-CMD java -jar target/steve.jar
+# Release Stage
+FROM eclipse-temurin:17-jdk AS release
+
+# Copy only the generated jar file from the build stage
+COPY --from=build /code/target /app
+
+# Expose any necessary ports (example: 8080)
+EXPOSE 8080
 
+# Define the entrypoint for the release stage
+CMD ["java", "-jar", "/app/steve.jar"]