Add docker files

Author: aNNiMON

.dockerignore

@@ -0,0 +1,5 @@
+.gradle
+.build-cache
+.idea
+build
+README.md

Dockerfile

@@ -0,0 +1,20 @@
+FROM gradle:6.6.1-jdk11 AS cache
+RUN mkdir -p /home/gradle/cache_home
+ENV GRADLE_USER_HOME=/home/gradle/cache_home
+COPY build.gradle /home/gradle/java-code/
+WORKDIR /home/gradle/java-code
+RUN GRADLE_OPTS="-Xmx256m" gradle build --build-cache --stacktrace -i --no-daemon
+
+FROM gradle:6.6.1-jdk11 as builder
+COPY --from=cache /home/gradle/cache_home /home/gradle/.gradle
+COPY . /usr/src/java-code
+WORKDIR /usr/src/java-code
+RUN GRADLE_OPTS="-Xmx256m" gradle shadowJar --build-cache --stacktrace --no-daemon
+
+FROM openjdk:11
+RUN mkdir -p /app
+COPY --from=builder /usr/src/java-code/build/libs/SimilarImagesBot-1.0-all.jar /app/SimilarImagesBot-1.0-all.jar
+ENV BOT_TOKEN ''
+ENV ADMIN_ID 0
+ENV MODE 'once'
+CMD java -jar /app/SimilarImagesBot-1.0-all.jar

build.gradle

@@ -8,7 +8,7 @@ sourceCompatibility = 11
 targetCompatibility = 11
 mainClassName = 'com.annimon.similarimagesbot.Main'
 group 'com.annimon'
-version '1.0-SNAPSHOT'
+version '1.0'
 
 repositories {
     jcenter()

src/main/java/com/annimon/similarimagesbot/Main.java

@@ -10,13 +10,20 @@ public static void main(String[] args) {
         final ImageIndexer indexer = new ImageIndexer();
         final var handler = new BotHandler(botToken, indexer);
         handler.setAdminId(longProp("ADMIN_ID").orElse(0L));
-        if (args.length == 1 && args[0].equalsIgnoreCase("once")) {
+        if (isOnceMode() || (args.length == 1 && args[0].equalsIgnoreCase("once"))) {
+            System.out.println("Started in once mode");
             handler.runOnce();
         } else {
+            System.out.println("Started in listen mode");
             handler.run();
         }
     }
 
+    private static boolean isOnceMode() {
+        final var mode = stringProp("MODE").orElse("once");
+        return mode.equalsIgnoreCase("once");
+    }
+
     private static Optional<String> stringProp(String name) {
         return Optional.ofNullable(System.getenv(name))
                 .or(() -> Optional.ofNullable(System.getProperty(name)));