I open this issue to pick up a point that was made in #127 to support the --env-file parameter. As pointed out in #127 this would be useful e.g. to add some environment variables that contain sensitive information. This way sensitive environment variables could be stored in a private S3 bucket and be pulled in from there either directly or via a mounted volume.

If the --env-file parameter is supported I guess the documentation on Task Definition Parameters could also be improved. Under environment it is mentioned that it is not recommended to put sensitive information in there, however it does not point to a solution on how to do this otherwise.

Extract from issue #127:

[...] Ideally it would allow an s3 endpoint:

"containerDefinitions":[
  {
    "env_file":[
      { "bucket":"my-bucket", "key":"myenvlist" }
    ]
  }
]

Elastic Beanstalk lets you do something similar in the Dockerrun.aws.json for docker private repository configuration:

"Authentication":{
  "Bucket":"my-bucket",
  "Key":"mydockercfg"
},