Environment variables configure a container when you create it. The host shell and the container have separate environments; exporting a value on the host doesn't automatically pass it through. Use an explicit environment option or a supported environment file. Quote values that contain spaces so the shell passes one argument. Configuration such as region, retry count and log level can vary between instances of the same image. Credentials need a separate secret delivery design in production. These tasks use fictional nonsecret values and check the resulting container environment, including a branch name whose internal space must survive.