title: Mount a single config file onto an ECS service
body: <p>I come from a background in Kubernetes and I'm trying to learn AWS/ECS. In Kubernetes, you can use <code>ConfigMap</code> resources to mount simple one-off config files onto containers quickly and easily without having to go through all the trouble of setting up volumes. This also makes it very easy to configure services from Terraform, which is what I'm trying to do.</p>
  <p>Do AWS ECS Services have a feature like the Kubernetes Config Maps? I just need the dead-simplest way to insert arbitrary text files into my services on startup, which can be updated with Terraform quickly. I want to avoid having to rebuild the whole image every time this file changes.</p>
  <p>Is this possible or do I need to create volumes for this? If so, what's the best type of volume configuration for this purpose? I can store and update the files in S3 easily, and these are just simple config files that only need read access, so would this be an acceptable case to just mount the S3 bucket?</p>