Expose Prometheus metrics (#355)

pom.xml

@@ -317,6 +317,13 @@
             <version>${spring_boot_version}</version>
         </dependency>
 
+        <!-- https://mvnrepository.com/artifact/io.micrometer/micrometer-registry-prometheus -->
+        <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-registry-prometheus</artifactId>
+            <version>1.8.5</version>
+        </dependency>
+
         <dependency>
             <groupId>com.zaxxer</groupId>
             <artifactId>HikariCP</artifactId>

src/main/resources/application.yaml

@@ -4,7 +4,7 @@ management:
   endpoints:
     web:
       exposure:
-        include: "health"
+        include: "health,prometheus"
 spring:
   main:
     allow-circular-references: true