Running docker in AWS ECS and passing env file - amazon-web-services

Question

I need to run a docker container in AWS ECS. I do NOT have access to the source code for the image. This is a private image, from a private repo that I have uploaded to AWS ECR. I have created an AWS ECS Task Definition to run the container inside a service, inside a cluster. The image shows as being up and running but I cannot hit it via my browser. I know that all the network settings are correct because I can hit a simple hello world app that I also deployed to test.
There is also a command I need to run before: docker run --env-file <environment_variables_file> <image>:<tag> rake db:reset && rake db:seed.
According to the instructions for this docker image, the run command for it is: docker run -d --name <my_image_name> --env-file <environment_variables_file> -p 8080:80 <image>:<tag>.
I can run this image locally on my laptop with no issues, deploying it to AWS is that problem.
My question is how do I provide the environment_variables_file to the image? Where do I upload the file and how do I pass it? How do I run the command to init the DB before the image runs?

Answer 1

Since Nov 2020, ECS does support env files (blog post), but they must be hosted on S3:
https://docs.aws.amazon.com/AmazonECS/latest/developerguide/taskdef-envfiles.html
Pasting the essentials for reference. Under container definition:
"environmentFiles": [
{
"value": "arn:aws:s3:::s3_bucket_name/envfile_object_name.env",
"type": "s3"
}
]
The task execution role also needs the following permission:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::s3_bucket_name/envfile_object_name.env"
]
},
{
"Effect": "Allow",
"Action": [
"s3:GetBucketLocation"
],
"Resource": [
"arn:aws:s3:::s3_bucket_name"
]
}
]
}

Answer 2

Amazon ECS doesn't support environment variable files. You can set environment variables inside task definition. For example:
"environment" : [
{ "name" : "string", "value" : "string" },
{ "name" : "string", "value" : "string" }
]
Please read following instructions for more details.
Update:
AWS now provides a way -
https://docs.aws.amazon.com/AmazonECS/latest/developerguide/taskdef-envfiles.html