added jmx exporter agent

config/Dockerfile.backend

@@ -6,7 +6,8 @@ FROM $BUILDER_IMAGE AS builder
 ARG MVN_FLAGS="-Pprod"
 
 RUN apt-get update \
- && apt-get -y install git glibc-locales java-17-openjdk-devel maven node \
+ && apt-get -y install git glibc-locales java-17-openjdk-devel maven node curl \
+ && curl --location --insecure https://github.com/prometheus/jmx_exporter/releases/download/1.3.0/jmx_prometheus_javaagent-1.3.0.jar -o jmx_prometheus_javaagent.jar \
  && apt-get clean
 
 ENV JAVA_HOME=/usr/lib/jvm/java
@@ -22,7 +23,6 @@ RUN mkdir -p $HOME/.m2 \
  && mvn clean \
  && mvn package -T4C ${MVN_FLAGS}
 
-
 FROM $RUNTIME_IMAGE
 ARG ADMIN_PASSWORD=Secr3t
 
@@ -30,11 +30,16 @@ USER root
 
 COPY config/tomcat /
 
+ENV CATALINA_OPTS="-javaagent:/opt/jmx_exporter/jmx_prometheus_javaagent.jar=8081:/opt/jmx_exporter/config.yaml"
+
 RUN cat /etc/tomcat/webbpm.properties >> /etc/tomcat/catalina.properties \
  && sed -i -r "s/<must-be-changed>/$ADMIN_PASSWORD/g" /etc/tomcat/tomcat-users.xml \
  && chown root:tomcat /var/lib/tomcat/webapps \
  && chmod g+rw /var/lib/tomcat/webapps
 
+COPY --from=builder jmx_prometheus_javaagent.jar /opt/jmx_exporter/jmx_prometheus_javaagent.jar
+COPY config/jmx_exporter.yaml /opt/jmx_exporter/config.yaml
+
 USER tomcat
 
 COPY --from=builder /app/backend/target/fl*.war /var/lib/tomcat/webapps/fl.war

config/jmx_exporter.yaml

@@ -0,0 +1,39 @@
+lowercaseOutputLabelNames: true
+lowercaseOutputName: true
+whitelistObjectNames: ["java.lang:type=OperatingSystem", "Catalina:*"]
+blacklistObjectNames: []
+rules:
+  - pattern: 'Catalina<type=Server><>serverInfo: (.+)'
+    name: tomcat_serverinfo
+    value: 1
+    labels:
+      serverInfo: "$1"
+    type: COUNTER
+  - pattern: 'Catalina<type=GlobalRequestProcessor, name=\"(\w+-\w+)-(\d+)\"><>(\w+):'
+    name: tomcat_$3_total
+    labels:
+      port: "$2"
+      protocol: "$1"
+    help: Tomcat global $3
+    type: COUNTER
+  - pattern: 'Catalina<j2eeType=Servlet, WebModule=//([-a-zA-Z0-9+&@#/%?=~_|!:.,;]*[-a-zA-Z0-9+&@#/%=~_|]), name=([-a-zA-Z0-9+/$%~_-|!.]*), J2EEApplication=none, J2EEServer=none><>(requestCount|processingTime|errorCount):'
+    name: tomcat_servlet_$3_total
+    labels:
+      module: "$1"
+      servlet: "$2"
+    help: Tomcat servlet $3 total
+    type: COUNTER
+  - pattern: 'Catalina<type=ThreadPool, name="(\w+-\w+)-(\d+)"><>(currentThreadCount|currentThreadsBusy|keepAliveCount|connectionCount|acceptCount|acceptorThreadCount|pollerThreadCount|maxThreads|minSpareThreads):'
+    name: tomcat_threadpool_$3
+    labels:
+      port: "$2"
+      protocol: "$1"
+    help: Tomcat threadpool $3
+    type: GAUGE
+  - pattern: 'Catalina<type=Manager, host=([-a-zA-Z0-9+&@#/%?=~_|!:.,;]*[-a-zA-Z0-9+&@#/%=~_|]), context=([-a-zA-Z0-9+/$%~_-|!.]*)><>(processingTime|sessionCounter|rejectedSessions|expiredSessions):'
+    name: tomcat_session_$3_total
+    labels:
+      context: "$2"
+      host: "$1"
+    help: Tomcat session $3 total
+    type: COUNTER