docker image build improvements

.dockerignore

@@ -0,0 +1,128 @@
+### Java template
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+replay_pid*
+
+### Maven template
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+# https://github.com/takari/maven-wrapper#usage-without-binary-jar
+.mvn/wrapper/maven-wrapper.jar
+
+# Eclipse m2e generated files
+# Eclipse Core
+.project
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+
+### JEnv template
+# JEnv local Java version configuration file
+.java-version
+
+# Used by previous versions of JEnv
+.jenv-version
+
+### Eclipse template
+.metadata
+bin/
+tmp/
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.settings/
+.loadpath
+.recommenders
+
+# External tool builders
+.externalToolBuilders/
+
+# Locally stored "Eclipse launch configurations"
+*.launch
+
+# PyDev specific (Python IDE for Eclipse)
+*.pydevproject
+
+# CDT-specific (C/C++ Development Tooling)
+.cproject
+
+# CDT- autotools
+.autotools
+
+# Java annotation processor (APT)
+.factorypath
+
+# PDT-specific (PHP Development Tools)
+.buildpath
+
+# sbteclipse plugin
+.target
+
+# Tern plugin
+.tern-project
+
+# TeXlipse plugin
+.texlipse
+
+# STS (Spring Tool Suite)
+.springBeans
+
+# Code Recommenders
+.recommenders/
+
+# Annotation Processing
+.apt_generated/
+.apt_generated_test/
+
+# Scala IDE specific (Scala & Java development for Eclipse)
+.cache-main
+.scala_dependencies
+.worksheet
+
+# Uncomment this line if you wish to ignore the project description file.
+# Typically, this file would be tracked if it contains build/dependency configurations:
+#.project
+
+### JDeveloper template
+# default application storage directory used by the IDE Performance Cache feature
+.data/
+
+# used for ADF styles caching
+temp/
+
+# default output directories
+classes/
+deploy/
+javadoc/
+
+# lock file, a part of Oracle Credential Store Framework
+cwallet.sso.lck

Dockerfile

@@ -1,14 +1,22 @@
-FROM eclipse-temurin:11-jdk-focal
+FROM maven:3.9.9-eclipse-temurin-11-focal AS builder
+
+ENV MAVEN_OPTS="-Dmaven.repo.local=/opt/maven"
+ENV M2_HOME="/opt/maven/m2"
+
+WORKDIR /project
+COPY . /project
+
+RUN --mount=type=cache,target=/opt/maven/m2 mvn clean package -DskipTests
+
+FROM eclipse-temurin:11-jdk-focal AS runtime
 LABEL authors="jens"
 
 # Set working directory
 WORKDIR /app
 
-# Copy jar with dependencies
-COPY target/CorrelationDetective-1.0-jar-with-dependencies.jar /app/cd.jar
+# Copy fat jar
+COPY --from=builder /project/target/CorrelationDetective-1.0-jar-with-dependencies.jar /app/cd.jar
 
-# Create a directory to store input data
-RUN mkdir /app/data
 
 # Set the entrypoint to running the jar file
 ENTRYPOINT ["java", "-cp", "cd.jar", "core/Main"]