wemake-services / dotenv-linter

☺️ Linting dotenv files like a charm!

dotenv-linter

Simple linter for .env files.

While .env files are very simple it is required to keep them consistent This tool offers a wide range of consistency rules and best practices.

And it integrates perfectly to any existing workflow.

Read the announcing post.

Installation and usage

pip install dotenv-linter

And then run it:

dotenv-linter .env .env.template

See Usage section for more information.

Examples

There are many things that can go wrong in your .env files:

# Next line has leading space which will be removed:
 SPACED=
# Equal signs should not be spaced:
KEY = VALUE
# Quotes won't be preserved after parsing, do not use them:
SECRET="my value"

# Beware of duplicate keys!
SECRET=Already defined ;(

# Respect the convention, use `UPPER_CASE`:
kebab-case-name=1
snake_case_name=2

And much more! You can find the full list of violations in our docs.

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View on GitHub

Background

As a part of our "not blaming but fixing" corporate culture we build a lot of tools that prevent us from making the same mistakes over and over again.

dotenv-linter is one of these tools.

Some time ago we had several problems with .env files:

Some developers used CONSTANT_CASE for variable names and some developers used snake_case for that. While this is not a technical issue, but it is not very practical to mix these two cases and then think: what case I have used for this particular variable? Consistency is important!
We also had a problem with quotes and extra spaces. Some developers used KEY=VALUE and some used KEY = "VALUE" while in fact, these two examples will resolve in exactly the same thing - we prefer to have one-- and preferably only one --obvious way to do it. So, we now stick to KEY=VALUE notation
We also once had a duplicate key that ruined my day. I have spent several hours debugging my app because of this simple issue. That was a turning point for me and I have decided: let's automate it!

Installation

You can install it via pip (or any other similar tool):

$ pip install dotenv-linter

Why pip? Because python is present almost on all Linux setups. And we try to make this tool as portable as possible.

Usage

Usage is really simple:

$ dotenv-linter path/to/your/.env even/multiple/files/are/fine/.env

Real-life examples

If you are interested in how we use it real life applications you can have a look at (and even try!) our django template. Here's the line that invokes it.

We also have a full list of linting rules in our docs, check it out.

Conclusion

I hope this simple tool will save you some time, make your project more consistent, and your life slightly better. Add me on github to stay informed about the tools I am building!