Last week I ended up spending more time than I expected on debugging. I spent most of the time figuring out why a library did not accept my freshly generated RSA private key. I was supposed to provide the RSA private key as an environment variable RSA_PRIVATE_KEY. I wanted to store the RSA private key in a file private-key.pem so my first attempt became RSA_PRIVATE_KEY=\"$(cat private-key.pem)\" docker-compose up -d, which failed due to decoding issues by the library. It would appear that the library was very strict on the format of the private key. After a lot of debugging, I managed to figure out how I was supposed to provide the private key and I will try to share my learnings here.