PLAT-1798 - set env vars for AWS creds from cached credentials…

[dschep]

What did you implement

Allows for use of credentials provided by a deploy profile in the
serverless dashboard

Closes PLAT-1798

How can we verify it

on a system with no credentials, set up a project using serverless dashbaord with an access role in your deploy profile. then create a project with sls create -t aws-nodejs then replace the handler.js with

const AWS = require('aws-sdk');
const sts = new AWS.STS();
module.exports.hello = async () => {
  await sts.getCallerIdentity();
}

and configure your app/org in serverless.yml with the respective values from your dashboard config.

then install this branch and invoke

npm i -g serverless/serverless#sfe-creds-invoke-local
sls invoke local -f hello

it should work. on master it should fail due to lack of creds

Todos

Useful Scripts

• npm run test-ci --> Run all validation checks on proposed changes
• npm run lint-updated --> Lint all the updated files
• npm run lint:fix --> Automatically fix lint problems (if possible)
• npm run prettier-check-updated --> Check if updated files adhere to Prettier config
• npm run prettify-updated --> Prettify all the updated files

• Write and run all tests
• Write documentation
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO