Getting AWS Credentials into a Docker Container without Hardcoding It

-- 2017-01-15 --

EDIT (3 June 2018): There are security concerns with following this approach. Check out this great article on why.

When I'm building with ECS, I'm more often than not building a worker that interacts with other AWS services. I need my AWS Access Key ID and my AWS Secret Access Key for it to work locally.
Nobody wants hard-coded values being pushed to version control nor do you want to have to dig it up every time you need to develop locally.

Set up your AWS credentials per the official docs. The highlights taken from this page are as follows:

  • Set credentials in the AWS credentials profile file on your local system, located at:

    • ~/.aws/credentials on Linux, OS X, or Unix
    • C:\Users\USERNAME\.aws\credentials on Windows

This file should contain lines in the following format:

[default]
aws_access_key_id = your_access_key_id
aws_secret_access_key = your_secret_access_key
  • Substitute your own AWS credentials values for the values your_access_key_id and your_secret_access_key.
  • Set the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

To set these variables on Linux, OS X, or Unix, use export:

export AWS_ACCESS_KEY_ID=your_access_key_id
export AWS_SECRET_ACCESS_KEY=your_secret_access_key
# To set these variables on Windows, use set:set AWS_ACCESS_KEY_ID=your_access_key_id
set AWS_SECRET_ACCESS_KEY=your_secret_access_key

Running $ aws help we see there is a –profile parameter. Leveraging this, we can write a shell script to get our credentials into our Docker container.

AWS_ACCESS_KEY_ID=$(aws --profile default configure get aws_access_key_id)
AWS_SECRET_ACCESS_KEY=$(aws --profile default configure get aws_secret_access_key)

docker build -t my_app .
docker run -it --rm \
   -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
   -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY

Now we can run locally, push to version control and not worry about our credentials being exposed in version control. Plus, you can build and run your Docker container with one command now, woohoo.

-- Cameron Eckelberry