TIL: Docker Env Vars Use Equal Signs — Developer Distinction

I did something pretty stupid a week or two ago. I was setting up a MariaDB database using Docker-compose, and I kept getting an error saying that MYSQL_ROOT_PASSWORD was not set. This made no sense to me - of course MYSQL_ROOT_PASSWORD is in the .env file, right?

Wrong. I accidentally used colons ( a carry-over from a CF script) instead of equal signs.

How Not To Write A .env File

# WRONG
MYSQL_USER:runDockerTests
MYSQL_ROOT_PASSWORD:kjhsdfkjh98798798
MYSQL_DATABASE:myDB

Notice the colons, people.

How To Write A .env File

# RIGHT
MYSQL_USER=runDockerTests
MYSQL_ROOT_PASSWORD=kjhsdfkjh98798798
MYSQL_DATABASE=myDB

ahh, delightful equal signs, whether in Docker-compose.yml or .env files.

And of course, I capped it off by proclaiming my stupidity on Twitter.