MySQL Access Denied From Within Docker Containers
A few days ago I ran into some very odd behavior. Even though I was setting my usernames and passwords via Docker secrets (so the same file on the db container and the app container), MySQL was throwing Access Denied errors at me. Thankfully all the frustrating details of my troubleshooting have left me, but I thought I would share both the problem, and the solution.
The Setup
Be running multiple MySQL containers, and their associated application containers, on the same Docker network.