Added spotify formatter (expect failure)

Signed-off-by: or-shachar <[email protected]>

.circleci/config.yml

@@ -13,6 +13,16 @@ jobs:
           paths:
             - ~/.m2
           key: circleci-demo-java-spring-{{ checksum "pom.xml" }}
+      - run: 
+          name: Check formatting
+          command: |
+            if (mvn fmt:format);
+            then
+              echo "Code is well formatted"
+            else
+              echo "Code is not formatted well. Please run 'mvn fmt:format' and commit changes"
+              exit 1
+            fi 
       - run: mvn package
   publish_image:
     docker:

CONTRIBUTING.md

@@ -11,6 +11,13 @@ Prometheus uses GitHub to manage reviews of pull requests.
   This will avoid unnecessary work and surely give you and us a good deal
   of inspiration.
 
+# Formatting
+
+Code is automatically formatted with [Spotify fmt mavne-plugin](https://github.com/spotify/fmt-maven-plugin) whenever you run standard `mvn install`.
+
+CI builds will fail if code is not formatted that way.
+
+To simply run the formatter you can always run: `mvn fmt:format` (requires JVM > 11)
 # Releasing
 
 For release instructions, see [RELEASING](RELEASING.md).

pom.xml

@@ -208,6 +208,18 @@
               </execution>
           </executions>
       </plugin>
+      <plugin>
+        <groupId>com.spotify.fmt</groupId>
+        <artifactId>fmt-maven-plugin</artifactId>
+        <version>2.18</version>
+        <executions>
+            <execution>
+                <goals>
+                    <goal>format</goal>
+                </goals>
+            </execution>
+        </executions>
+    </plugin>
     </plugins>
   </build>