Motivation
Projects often rely on environmental variables stored in a .env
file to run... and because these
variables sometimes contain sensitive data, we never add them to source control.
Instead, these variables are added e.g. to a .env.example
file so it's easy to
get the project running for other developers. However, it's very easy to forget to update this file
when a variable is added/updated in .env
(during development). This can make
it difficult for devs to get the project running (locally) because they rely on
.env.example
file to setup their environment (with their own configs).
Enter sync-dotenv
Description
sync-dotenv
automates the process of keeping your
.env
in sync with .env.example
.
Installation
$ npm install -g sync-dotenv
Install as a dev dependency (recommended)
$ npm install -D sync-dotenv
Usage
By default, sync-dotenv
looks for a .env
in your working directory and
attempt to sync with .env.example
when no argument is provided. Failure
to find these files will cause the sync to fail.
$ sync-dotenv
Alternatively, you can use the --env
and --sample
flag to specify the source and destination file.
$ sync-dotenv --env foo/.env --sample bar/.env.example
Also, in the situation where you want to keep multiple files in sync with one source env
file you can make use of the --samples
flag specifying a globbing pattern to match:
$ sync-dotenv --env foo/.env --samples "env-samples/*"
# note: glob pattern should be provided as a string as shown above
For CLI options, use the --help
flag
$ sync-dotenv --help
To run sync-dotenv
whenever the .env
file changes, you can for example use nodemon
:
$ nodemon --watch .env --exec 'sync-dotenv --env .env --sample .env.example'
Examples
Sync (with .env.example
) before every commit using husky
// package.json
{
"scripts": {
"env": "sync-dotenv"
},
"husky": {
"hooks": {
"pre-commit": "npm run env",
}
}
}
Or with file other than .env.example
{
"scripts": {
- "env": "sync-dotenv"
+ "env": "sync-dotenv --sample .env.development"
}
}
Preserving variables in sample env
Sometimes you need to preserve certain variables in your example env file, you can optionally allow this by adding a sync-dotenv
config in package.json
like so
// package.json
"scripts": {
...
},
"sync-dotenv": {
"preserve": ["CHANNEL"]
}
Avoid comments or empty lines in sample env
You might not want to copy empty lines or comments to your sample env, in this case you can still use sync-dotenv
config in package.json
with the following:
// package.json
"scripts": {
...
},
"sync-dotenv": {
"emptyLines": true,
"comments": false
}
Note that you can still combine those options with preserve
.
Related
- parse-dotenv - zero dependency
.env
to javascript object parser
Contributors
Thanks goes to these wonderful people (emoji key):
Luqman Olushi O. | Bolaji Olajide | Kizito Akhilome |
This project follows the all-contributors specification. Contributions of any kind welcome!
License
This project is licensed under MIT