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Use this Lambda extension script (wrapperscript) to preload secret manager secrets to environment variables

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aws-get-secret

This is a utility much like the awesome gcp-get-secret from Binx.io. You can wrap it around your application that consumes environment variables containing secrets. By calling aws-get-secret -- [your-cli] [--your-args] it will call your cli command (server, serverless, etc.) and fill any environment variable that starts with the aws:/// format documented below.

Note: use any libary dealing with secrets with great care. Actions you can take to prevent impact:

  1. Do not trust me. Pin down your dependencies to exact SHA-512 hashes like with npm package-lock and Golang's go.sum.
  2. Do not trust any other module (node, etc) you install: vet them & pin them.
  3. Install upgrades only after careful review & again pin your dependencies.
  4. Rotate your secrets frequently, to make it something you do with ease.
  5. Seriously, pin your dependencies.

Forks welcome

If you miss functionality, feel free to fork the repository & optionally send Pull Requests to contribute back.

Usage

First, set some environment variables that define where to get the secret:

export FIRST_SECRET=aws:///arn:aws:secretsmanager:eu-central-1:1234567:secret:First-ABCDEF
export OTHER_SECRET=aws:///arn:aws:secretsmanager:eu-central-1:1234567:secret:Other-ABCDEF

You can define query parameters on the aws:/// uri just like with binxio/gcp-get-secret:

  • default to set a default value if there is no value
  • template to pick values from a JSON secret or to wrap the value with other data
  • destination and chmod to write to a file instead of using the environment

Then wrap your executable with this tool:

# quick example:
./aws-get-secret sh -c 'echo Something $SECRET;'

# NodeJS server:
./aws-get-secret node dist/server.js

# Python server server:
./aws-get-secret python3 server.py

AWS Lambda

Call this tool as a Lambda extension script (wrapperscript) to preload secret manager secrets to environment variables.

To use this wrapper script, create a Layer including the go binary of this repository. Then include the binary in another layer and invoke it by setting AWS_LAMBDA_EXEC_WRAPPER=/opt/aws-get-secret on your lambda. Alternatively, you can use the NodeJS CDK-compatible package which does this for you.

npm i aws-get-secret-lambda

Then wrap your Lambda like this (if you're using CDK):

import { wrapLambdasWithSecrets } from "aws-get-secret-lambda"

export class SomeStack extends Stack {
  constructor(scope: Construct) {
    super(scope, 'SomeStack');

    wrapLambdasWithSecrets(this.getAllFunctions());
  }
}

Refs

  1. https://github.com/aws-samples/aws-lambda-environmental-variables-from-aws-secrets-manager
  2. https://dev.to/aws-builders/getting-the-most-of-aws-lambda-free-compute-wrapper-scripts-3h4b
  3. https://docs.aws.amazon.com/lambda/latest/dg/runtimes-modify.html#runtime-wrapper
  4. https://github.com/binxio/gcp-get-secret
  5. https://www.hermanbanken.nl/2022/03/31/aws-get-secret/

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Use this Lambda extension script (wrapperscript) to preload secret manager secrets to environment variables

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