Environment variable is a key-value pair, external to an application's code, used to store configuration information like database connection strings or API keys. They allow sensitive data to be kept out of source control and provide flexibility for deploying the same application in multiple environments, like staging and production, with different settings.
I can't believe the new dev pushed his AWS secret key as an environment variable in the GitHub repo - now we have to rotate all our credentials!
The "10x engineer" refused to do any work until the DevOps team set up his 27 environment variables for his "productivity stack" of vim plugins and zsh aliases.
12 Factor App Configuration: This post from the classic 12 Factor App methodology explains why environment variables are key for externalizing config.
Kubernetes Secrets: Kubernetes provides a "Secret" object for injecting sensitive environment variables into containers, a more secure alternative to config files.
AWS Lambda Environment Variables: See how serverless platforms like AWS Lambda support environment variable configuration for functions.
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