What is env-cmd?
The env-cmd npm package allows you to easily set environment variables from a file or inline before running a command. This is particularly useful for managing different environments (development, testing, production) without hardcoding environment variables in your code.
What are env-cmd's main functionalities?
Load environment variables from a file
This feature allows you to load environment variables from a specified file before running your command. The file should follow the standard .env format.
env-cmd -f ./path/to/.env node app.js
Load environment variables from multiple files
You can load environment variables from multiple files. This is useful for layering configurations, such as having a base configuration and an environment-specific override.
env-cmd -f ./path/to/.env -f ./path/to/.env.local node app.js
Inline environment variables
This feature allows you to set environment variables inline directly in the command. This is useful for quick tests or temporary overrides.
env-cmd -e 'NODE_ENV=production' node app.js
JSON configuration
You can also pass environment variables as a JSON object. This is useful for more complex configurations that might be easier to manage in JSON format.
env-cmd -e '{"NODE_ENV": "production", "API_KEY": "12345"}' node app.js
Other packages similar to env-cmd
dotenv
dotenv is a popular package for loading environment variables from a .env file into process.env. Unlike env-cmd, dotenv is typically used by requiring it in your code, rather than as a command-line tool.
cross-env
cross-env allows you to set environment variables across different platforms (Windows, Linux, macOS) in a consistent manner. It is similar to env-cmd but focuses more on cross-platform compatibility.
dotenv-cli
dotenv-cli is a command-line interface for dotenv, allowing you to load environment variables from a .env file before running a command, similar to env-cmd. It provides a simpler interface but lacks some of the advanced features of env-cmd.
env-cmd
A simple node program for executing commands using an environment from an env file.
Install
npm install env-cmd
or npm install -g env-cmd
Basic Usage
Environment file ./test/.env
# This is a comment
ENV1=THANKS
ENV2=FOR ALL
ENV3=THE FISH
Package.json
{
"scripts": {
"test": "env-cmd ./test/.env mocha -R spec"
}
}
or
Terminal
./node_modules/.bin/env-cmd ./test/.env node index.js
Advanced Usage
--fallback
file usage option
You can specify an .env.local
(or any name) env file, add that to your .gitignore
and use that in your local development environment. Then you can use a regular .env
file in root directory with production configs that can get committed to a private/protected repo. When env-cmd
cannot find the .env.local
file it will fallback to looking for a regular .env
file.
Environment file ./.env.local
# This is a comment
ENV1=THANKS
ENV2=FOR ALL
ENV3=THE FISH
Fallback Environment file ./.env
# This can be used as an example fallback
ENV1=foo
ENV2=bar
ENV3=baz
ENV4=quux
ENV5=gorge
Package.json
uses ./.env
as a fallback
{
"scripts": {
"test": "env-cmd --fallback ./.env.local mocha -R spec"
}
}
or
Terminal
./node_modules/.bin/env-cmd ./.env.local node index.js
.rc
file usage
For more complex projects, a .env-cmdrc
file can be defined in the root directory and supports as many environments as you want. Instead of passing the path to a .env
file to env-cmd
, simply pass the name of the environment you want to use thats in your .env-cmdrc
file. You may also use multiple environment names to merge env vars together.
.rc file .env-cmdrc
{
"development": {
"ENV1": "Thanks",
"ENV2": "For All"
},
"test": {
"ENV1": "No Thanks",
"ENV3": "!"
},
"production": {
"ENV1": "The Fish"
}
}
Terminal
./node_modules/.bin/env-cmd production node index.js
./node_modules/.bin/env-cmd test,production node index.js
--no-override
option
Sometimes you want to set env variables from a file without overriding existing process env vars or shell env vars.
Terminal
ENV1=welcome ./node_modules/.bin/env-cmd --no-override ./test/.env node index.js
Environment File Formats
These are the currently accepted environment file formats. If any other formats are desired please create an issue.
key=value
- Key/value pairs as JSON
- JavaScript file exporting an object
.env-cmdrc
file (as valid json) in execution directory
Path Rules
This lib attempts to follow standard bash
path rules. The rules are as followed:
Home Directory = /Users/test
Working Directory = /Users/test/Development/app
Type | Input Path | Expanded Path |
---|
Absolute | /some/absolute/path.env | /some/absolute/path.env |
Home Directory with ~ | ~/starts/on/homedir/path.env | /Users/test/starts/on/homedir/path.env |
Relative | ./some/relative/path.env or some/relative/path.env | /Users/test/Development/app/some/relative/path.env |
Relative with parent dir | ../some/relative/path.env | /Users/test/Development/some/relative/path.env |
Why
Because sometimes its just too cumbersome passing lots of environment variables to scripts. Its usually just easier to have a file with all the vars in them, especially for development and testing.
Do not commit sensitive environment data to a public git repo!
Related Projects
cross-env
- Cross platform setting of environment scripts
Special Thanks
Special thanks to cross-env
for inspiration (use's the same cross-spawn
lib underneath too).
Contributors
- Eric Lanehart
- Jon Scheiding
- Alexander Praetorius
- Anton Versal
Contributing Guide
I welcome all pull requests. Please make sure you add appropriate test cases for any features added. Before opening a PR please make sure to run the following scripts:
npm run lint
checks for code errors and formats according to js-standardnpm test
make sure all tests passnpm run test-cover
make sure the coverage has not decreased from current master