Compose supports declaring default environment variables in an environment
file named .env
placed in the folder docker-compose
command is executed from
(current working directory).
Compose expects each line in an env file to be in VAR=VAL
format. Lines
beginning with #
(i.e. comments) are ignored, as are blank lines.
Note: Values present in the environment at runtime will always override those defined inside the
.env
file. Similarly, values passed via command-line arguments take precedence as well.
Those environment variables will be used for variable substitution in your Compose file, but can also be used to define the following CLI variables:
COMPOSE_API_VERSION
COMPOSE_CONVERT_WINDOWS_PATHS
COMPOSE_FILE
COMPOSE_HTTP_TIMEOUT
COMPOSE_TLS_VERSION
COMPOSE_PROJECT_NAME
DOCKER_CERT_PATH
DOCKER_HOST
DOCKER_TLS_VERIFY