Expose JMX port in a docker Container running on ECS Cluster

Question

I have a java application that is running inside a docker container. I have deployed this container in an ECS cluster. I want to expose a JMX port so I can collect JVM stats using CollectD agent installed on that machine.

The JVM params that I have specified in my Java app are

JAVA_OPTS="-Dspring.config.location=classpath:/base/ -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8008 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.net.preferIPv4Stack=true -Djava.rmi.server.hostname=10.0.7.118

I am able to connect to this JMX port if I run this application in a non docker environment. However, I am unable to do the same in Docker.

I have also given port mappings in My Task Definition so this port can be exposed to the outer world. I know, If I was running this docker using docker run command than I could have specified -p param for port mapping, but I can not do the same here as I am running this app on an ECS cluster which deploys this image. So I have to rely on port mappings provided by task definition.

TaskDefnition

            "ContainerDefinitions": [
                {
                    "Name": "MyApplication",
                    "Cpu": "2048",
                    "Essential": "true",
                    "Image": "location of the image",
                    "Memory": "8192",
                    "MemoryReservation": "4096",
                    "Environment": [
                        {
                            "Name": "Test",
                            "Value": {
                                "Fn::GetAtt": [
                                    "SomeAttrib",
                                    "SomeAccessKey"
                                ]
                            }
                        }
                    ],
                    "PortMappings": [
                        {
                            "HostPort": "8080",
                            "ContainerPort": "8080"
                        },
                        {
                            "HostPort": "8008",
                            "ContainerPort": "8008"
                        }
                    ]
                }

Answer 1

After going through various links I found the solution to my problem. Finally, JVM params look like this

-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8008 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.net.preferIPv4Stack=true -Djava.rmi.server.hostname=127.0.0.1 -Dcom.sun.management.jmxremote.rmi.port=8008 -Dcom.sun.management.jmxremote.local.only=true

Adding -Dcom.sun.management.jmxremote.local.only=true did the trick for me. You can set it to true or false depending on your requirement.