Files
docker-docs/compose/env-file.md
Misty Stanley-Jones a4f5e30249 Various copyedits to reduce future tense, wordiness, and use of 'please' (#5788)
* Reword lots of instances of 'will'

* Reword lots of instances of won't

* Reword lots of instances of we'll

* Eradicate you'll

* Eradicate 'be able to' type of phrases

* Eradicate 'unable to' type of phrases

* Eradicate 'has / have to' type of phrases

* Eradicate 'note that' type of phrases

* Eradicate 'in order to' type of phrases

* Redirect to official Chef and Puppet docs

* Eradicate gratuitous 'please'

* Reduce use of e.g.

* Reduce use of i.e.

* Reduce use of N.B.

* Get rid of 'sexagesimal' and correct some errors
2018-01-25 17:37:23 -08:00

56 lines
1.9 KiB
Markdown

---
description: Declare default environment variables in a file
keywords: fig, composition, compose, docker, orchestration, environment, env file
title: Declare default environment variables in file
---
Compose supports declaring default environment variables in an environment file
named `.env` placed in the folder where the `docker-compose` command is executed
*(current working directory)*.
## Syntax rules
These syntax rules apply to the `.env` file:
* Compose expects each line in an `env` file to be in `VAR=VAL` format.
* Lines beginning with `#` are processed as comments and ignored.
* Blank lines are ignored.
* There is no special handling of quotation marks. This means that
**they are part of the VAL**.
## Compose file and CLI variables
The environment variables you define here is used for [variable
substitution](compose-file/index.md#variable-substitution) in your Compose file,
and can also be used to define the following [CLI
variables](reference/envvars.md):
- `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`
> **Notes**
>
> * Values present in the environment at runtime always override
those defined inside the `.env` file. Similarly, values passed via command-line
arguments take precedence as well.
>
> * Environment variables defined in the `.env` file are not
automatically visible inside containers. To set container-applicable
environment variables, follow the guidelines in the topic [Environment variables
in Compose](/compose/environment-variables.md), which describes how to pass
shell environment variables through to containers, define environment variables
in Compose files, and more.
## More Compose documentation
- [User guide](index.md)
- [Command line reference](./reference/index.md)
- [Compose file reference](compose-file.md)