How do I retrieve the public IP for a fargate task using the CLI?

Question

I have a cluster running with services and am also able to launch fargate tasks from the command line. I can get the taskArn as a response to launching the task and I can wait for the task to be in the running state by using "aws ecs wait". I'm stuck figuring out how to get the the public IP of the task. I can find it via the web page easily enough and can access the machine via it's public IP...

How do I get the public IP of a fargate task using the CLI interface?

I'm using the following commands to launch the task, wait for it to run and retrieve the task description:

$ aws ecs run-task --launch-type FARGATE --cluster xxxx --task-definition xxxx --network-configuration xxxx $ aws ecs wait <taskArn> $ aws ecs describe-tasks --cluster xxxx --task <taskArn> | grep -i ipv4 

The last command only gives me the private IP...

"privateIpv4Address": "10.0.1.252", "name": "privateIPv4Address" 

I've also tried using:

$ ecs-cli ps --cluster xxxx 

But the Ports column is blank.

Name                                       State    Ports  TaskDefinition xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/xxxx  RUNNING         xxxx:1 xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/xxxx  RUNNING         xxxx:1 

Answer 1

Once I realized that describe-tasks gave me the ENI id along with the private IP I was able to get the public IP with:

$ aws ec2 describe-network-interfaces --network-interface-ids eni-xxxxxxxx 

Answer 2

This was specific to my usecase, but perhaps its useful to someone else (intended to be run as javascript in Lambda just after you run ecs.createService() )

Yes, I know this topic is for CLI but this is the first result that popped up when looking for "Fargate public IP" and i was looking for a javascript based solution.

// get container IP getContainerIP(myServiceName).then(ip=>{     console.log("Container IP address is: ", ip);  }).catch(err=>{     console.log(err); });    function getContainerIP(servicename){     // note: assumes that only 1 task with 1 container is in the provided service, and that a container only has 1 network interface      return new Promise(function(resolve, reject){       // get task arns (needs a delay because we just launched it)       setTimeout(getTasks, 6000);        // get task arns       function getTasks(){         ecs.listTasks({           cluster: process.env.ecs_cluster,           launchType: "FARGATE",           serviceName: servicename         },function(err, res){           if(err){             reject("Unable to get task list");             return;           }            // loop until we have a result           if(!res.taskArns.length){             setTimeout(getTasks, 2000);             return;           }            // get details           getTaskDetails(res.taskArns);         });       }        // get the details of the task (we assume only one task because that's how its configured)       function getTaskDetails(taskArns){         ecs.describeTasks({           cluster: process.env.ecs_cluster,           tasks: taskArns         },function(err,res){           if(err){             reject("Unable to get task details");             return;           }            // no results           if(!res.tasks.length || !res.tasks[0].attachments.length){             reject("No tasks available");             return;           }            // network needs to be in status ATTACHING to see the eni, else wait           if(res.tasks[0].attachments[0].status !== "ATTACHING"){             setTimeout(function(){ getTaskDetails(taskArns); }, 2000);             return;           }            // get network ID from result           let eni = "";           for(let i in res.tasks[0].attachments[0].details){             if(!res.tasks[0].attachments[0].details.hasOwnProperty(i)) continue;             if(res.tasks[0].attachments[0].details[i].name !== "networkInterfaceId") continue;              // get the eni             eni = res.tasks[0].attachments[0].details[i].value;             break;           }            // no eni           if(eni === ""){             reject("Unable to retrieve container ENI");             return;           }            // get network details           getNetworkDetails(eni);         });       }        // get network details       function getNetworkDetails(eni){          // get the ENI details         ec2.describeNetworkInterfaces({           NetworkInterfaceIds: [eni]         }, function(err, res) {           if(err){             reject("Unable to retrieve ENI details");             return;           }            // confirm available data           if(!res.NetworkInterfaces.length || typeof res.NetworkInterfaces[0].Association === "undefined" || typeof res.NetworkInterfaces[0].Association.PublicIp === "undefined"){             reject("Unable to retrieve IP from ENI details");             return;           }            // resolve the public IP address           resolve(res.NetworkInterfaces[0].Association.PublicIp);         });       }     }); }