[ECS] [request]: Container Dependency Not functioning as expected.

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**Tell us about your request**
What do you want us to build? Use of dependsOn to establish dependency between two containers, doesn’t work as expected for usecase where one container should start only when dependent container COMPLETEs/SUCCESS. Rather Container B dependsOn Container A with condition as ‘SUCCESS’. Container A terminates with non-zero exit code, Container B stuck in PENDING instead of termination due to dependency, making task stay in PENDING state indefinitely.

**Which service(s) is this request for?**
ECS

**Are you currently working around this issue?**
Container B depends on Container A using condition ‘COMPLETE’ instead of ‘SUCCESS’, so that non-zero exit of Container A will start Container B. Then, Container B uses tasks Metadata to determine the status of Container A exit-code and exits Container B in case Container A exited with non-zero code.

Review the ECS container dependency behavior described for a SUCCESS condition when the prerequisite container exits non-zero. Compare that behavior with the COMPLETE workaround and define completion as preventing the dependent container and task from remaining indefinitely in PENDING.

Written by the indexing model from the issue text.