rust-dotenv
Achtung! This is a v0.* version! Expect bugs and issues all around. Submitting pull requests and issues is highly encouraged!
Quoting bkeepers/dotenv:
Storing configuration in the environment is one of the tenets of a twelve-factor app. Anything that is likely to change between deployment environments–such as resource handles for databases or credentials for external services–should be extracted from the code into environment variables.
This library is meant to be used on development or testing environments in
which setting environment variables is not practical. It loads environment
variables from a .env
file, if available, and mashes those with the actual
environment variables provided by the operative system.
Usage
The easiest and most common usage consists on calling dotenv::dotenv
when the
application starts, which will load environment variables from a file named
.env
in the current directory or any of its parents; after that, you can just call
the environment-related method you need as provided by std::os
.
If you need finer control about the name of the file or its location, you can
use the from_filename
and from_path
methods provided by the crate.
dotenv_codegen
provides the dotenv!
macro, which
behaves identically to env!
, but first tries to load a .env
file at compile
time.
Examples
A .env
file looks like this:
# a comment, will be ignored
REDIS_ADDRESS=localhost:6379
MEANING_OF_LIFE=42
You can optionally prefix each line with the word export
, which will
conveniently allow you to source the whole file on your shell.
A sample project using Dotenv would look like this:
extern crate dotenv;
use dotenv;
use env;
Using the dotenv!
macro
Add dotenv_codegen
to your dependencies, and add the following to the top of
your crate:
extern crate dotenv_codegen;
Then, in your crate: