SOPs
SOPs is a tool for checking in secrets / password into version control system (eg. GitHub). We need to agree on only one thing, which is an AWS profile (with key and secret) that can decrypt the messages.
Usage
$ cd environments
# Encrypt
$ sops -e secrets.json > secrets.sops.json
# Decrypt
$ sops -d secrets.sops.json > secrets.json
# Edit encrypted file in place
$ sops secrets.sops.json