Make task not found error message for task protection endpoint consistent with Fargate

[amogh09]

Summary

Task Protection API on ECS Agent return a different error message on task lookup failure than Fargate Agent.

ECS Agent -

404 Not Found
{
  "error": {
    "Code": "ResourceNotFoundException",
    "Message": "Invalid request: no task was found"  // <------- THIS
  }
}

Fargate Agent -

404 Not Found
{
  "error": {
    "Code": "ResourceNotFoundException",
    "Message": "Failed to find a task for the request"  // <------- THIS
  }
}

To make the experience provide by ECS Agent and Fargate Agent consistent, we are changing ECS Agent's error message to match Fargate Agent. The HTTP status code and error code in the response is not being changed, so customers depending on the codes will not be affected. Error messages are informational only and customers shouldn't be driving logic based on them.

Implementation details

• Change the error message string used by task protection handlers when task lookup fails.
• Update the tests.

Testing

In addition to automated tests, manually invoked GetTaskProtection and UpdateTaskProtection endpoints with an incorrect endpoint ID.

$ curl -s -XPUT http://169.254.170.2/api/bad/task-protection/v1/state -d '{"ExpiresInMinutes": 5, "ProtectionEnabled": false}' | jq
{
  "error": {
    "Code": "ResourceNotFoundException",
    "Message": "Failed to find a task for the request"
  }
}
$ curl -s http://169.254.170.2/api/bad/task-protection/v1/state | jq
{
  "error": {
    "Code": "ResourceNotFoundException",
    "Message": "Failed to find a task for the request"
  }
}

New tests cover the changes: yes

Description for the changelog

Make task not found error message for task protection endpoint consistent with Fargate

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.