ECS Get Task ARN from Container Runtime Id

Question

In AWS ECS, the hostname of the docker container is the container runtime id. Is there any way that given a container rumtime id, the task ARN under which the container is running can be fetched?

Answer 1

There isn't any specific AWS command which can fetch the task ARN from the container runtime id. But this can be achieved using list-tasks and describe-tasks command of aws ecs, if you know the cluster and service name in prior.

Here is the idea of how you can achieve this:

tasksList=`aws ecs list-tasks --cluster mycluster --service-name myservice | awk '/mycluster/ {print}' | sed 's/,$//' | awk '{ sub(/^[ \t]+/, ""); print }' | awk '{printf "%s ",$0} END {print ""}'`
taskDesc="aws ecs describe-tasks --cluster mycluster --tasks ${tasksList}"
eval $taskDesc | awk '/taskArn|runtimeId/ {print $0}' | awk '{ sub(/^[ \t]+/, ""); print }' | awk '!visited[$0]++' | awk '/taskArn/ {$0=$0"->"} 1'

This will give you an output something like this:

"taskArn": "arn:aws:ecs:<aws_region>:<account_id>:task/mycluster/043de9ab06bb41d29e97576f1f1d1d33",->
"runtimeId": "191c90bae67844124ff2d079f4de997dc8cb9e3c93cd451d931c806283ea527d",
"runtimeId": "61e6fa6e1cbb5039e1c4df31d5c522b9439c22fbeff3c9cc1fb4429ffbb5a94d",
"taskArn": "arn:aws:ecs:<aws_region>:<account_id>:task/mycluster/14478901e8364466b8fd8236d6a66c5e",->
"runtimeId": "b679c5139f019f526c4301c8cc511723abd6aed3fa8cf9c397147d33275a860c",
"runtimeId": "0e727f660616df970b2cf767ea389bee97cd748ea9e09266cb5ee651ad2d2971",
"runtimeId": "ee7fb30715d9ff325eebcfacdde978179f07b1e3bf91a0dac92abd3b54970307",
"taskArn": "arn:aws:ecs:<aws_region>:<account_id>:task/mycluster/23d037af17f54a59afe50f810afdecf0",->
"runtimeId": "67d4ebea82e6e6622171816e1aef53489070aea5b03d5942e8e41c2dc4f49fd3",

Below every taskArn line, there are multiple runtimeId lines specifying the container runtime ids of the containers running under that task.

Hope this helps. Happy scripting.