How can I get the TaskId of a Fargate ecs Container - amazon-web-services

Question

Similar to this question How to get Task ID from within ECS container? but I want to get the TaskId for my Fargate task. How can you do this? Like others I want this for logging information.
I'm running a Spring App with ELK stack for logging and would like if possible to include the TaskId in the logs if possible.
Edit
I actually never got this to work by the way, here is my code:
private String getTaskIdInternal() {
String url = System.getenv("ECS_CONTAINER_METADATA_URI_V4") + "/task";
logger.info("Getting ecsMetaDataURL={}", url);
if (url == null) {
throw new RuntimeException("ECS_CONTAINER_METADATA_URI_V4 env variable not defined");
}
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<JsonNode> response = restTemplate.getForEntity(url, JsonNode.class);
logger.info("ecsMetaData={}", response);
JsonNode map = response.getBody();
String taskArn = map.get("TaskARN").asText();
String[] splitTaskArn = taskArn.split("/");
String taskId = splitTaskArn[splitTaskArn.length - 1];
logger.info("ecsTaskId={}", taskId);
return taskId;
}
But I always get this stack trace:
Could not get the taskId from ECS. exception=org.springframework.web.client.HttpClientErrorException: 403 Forbidden
at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:118)
at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:103)
at org.springframework.web.client.ResponseErrorHandler.handleError(ResponseErrorHandler.java:63)
at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:732)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:690)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:646)
at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:325)

Answer 1

If you're trying to get the task id in Fargate for ECS you make use of metadata endpoints.
Assuming you're using version 1.4.0 of Fargate you can get this via a http request to ${ECS_CONTAINER_METADATA_URI_V4}/task.
An example response from this endpoint is below
{
"Cluster": "arn:aws:ecs:us-west-2:&ExampleAWSAccountNo1;:cluster/default",
"TaskARN": "arn:aws:ecs:us-west-2:&ExampleAWSAccountNo1;:task/default/febee046097849aba589d4435207c04a",
"Family": "query-metadata",
"Revision": "7",
"DesiredStatus": "RUNNING",
"KnownStatus": "RUNNING",
"Limits": {
"CPU": 0.25,
"Memory": 512
},
"PullStartedAt": "2020-03-26T22:25:40.420726088Z",
"PullStoppedAt": "2020-03-26T22:26:22.235177616Z",
"AvailabilityZone": "us-west-2c",
"Containers": [
{
"DockerId": "febee046097849aba589d4435207c04aquery-metadata",
"Name": "query-metadata",
"DockerName": "query-metadata",
"Image": "mreferre/eksutils",
"ImageID": "sha256:1b146e73f801617610dcb00441c6423e7c85a7583dd4a65ed1be03cb0e123311",
"Labels": {
"com.amazonaws.ecs.cluster": "arn:aws:ecs:us-west-2:&ExampleAWSAccountNo1;:cluster/default",
"com.amazonaws.ecs.container-name": "query-metadata",
"com.amazonaws.ecs.task-arn": "arn:aws:ecs:us-west-2:&ExampleAWSAccountNo1;:task/default/febee046097849aba589d4435207c04a",
"com.amazonaws.ecs.task-definition-family": "query-metadata",
"com.amazonaws.ecs.task-definition-version": "7"
},
"DesiredStatus": "RUNNING",
"KnownStatus": "RUNNING",
"Limits": {
"CPU": 2
},
"CreatedAt": "2020-03-26T22:26:24.534553758Z",
"StartedAt": "2020-03-26T22:26:24.534553758Z",
"Type": "NORMAL",
"Networks": [
{
"NetworkMode": "awsvpc",
"IPv4Addresses": [
"10.0.0.108"
],
"AttachmentIndex": 0,
"IPv4SubnetCIDRBlock": "10.0.0.0/24",
"MACAddress": "0a:62:17:7a:36:68",
"DomainNameServers": [
"10.0.0.2"
],
"DomainNameSearchList": [
"us-west-2.compute.internal"
],
"PrivateDNSName": "ip-10-0-0-108.us-west-2.compute.internal",
"SubnetGatewayIpv4Address": ""
}
]
}
]
}
As you can see you would need to parse the TaskARN to get the TaskID (it is the last part of the ARN if you split by "/".
Amazon do specify the following in the documentation that should be noted.
For tasks using the Fargate launch type and platform versions prior to 1.4.0, the task metadata version 3 and 2 endpoint are supported. For more information, see Task Metadata Endpoint version 3 or Task Metadata Endpoint version 2.

Answer 2

The link in the accepted answer is for EC2 launch type. The direct doc link for Fargate is: https://docs.aws.amazon.com/AmazonECS/latest/userguide/task-metadata-endpoint-v4-fargate.html. The json content seems to be pretty much the same though.