Netlify Dev: Add support for .env files

[RaeesBhatti]

- Summary
Allows users to use .env files for their site generators and Netlify functions written in JS, when using netlify dev.
Fixes: #457
Fixes: #444
Fixes: #474
Fixes: #405

- Test plan

• Add .env file to your function directory with SOMETHING=true and see if it is accessible in function using process.env while running through netlify dev
• Add a similar .env file to the root of your project and see if it is available to your site framework (etc. React etc.) when running through netlify dev

- Description for the changelog

• Use dotenv package to parse .env file if exists and set the env variables to newly spawned site server process.
• Do the same for Netlify functions builder when running through netlify dev
• Use lambda-local to serve JS functions and pass path to function local .env file as parameter when executing

- A picture of a cute animal (not mandatory but encouraged)
🙈

[swyxio]

looks good but needs docs and tests. got to start having a habit of adding these alongside features or it just never gets done

[fool]

While I can't speak to the implementation, I think this is what is so desperately desired by our users. Best way to be sure it suits their needs is to let them test it in prod :)

[unclejustin]

So this seems to work for new variables in .env, but if I have an existing variable in netlify.com the "remote" variable overrides my local .env. This seems backwards to me. The whole point of a .env file is to use "dev" api key for local development and a production key in actual production. Am I missing something?

[RaeesBhatti]

@unclejustin I can confirm this behavior for Netlify Function. The cause for this is that dotenv doesn't override env variables that are already set. Please hold on while we figure this out.

[RaeesBhatti]

Being discussed here: #734
cc @unclejustin @jrunestone

[oles]

@RaeesBhatti

No matter what I do - I cannot access any variables from my .env file in my functions.
It doesn't matter if the .env file is in my root folder, inside the functions folder, inside a function folder.

netlify dev do report: Overriding the following env variables with .env file: BISNODE_API_KEY,BISNODE_API_SECRET

Though process.env do not contain neither.

On a side note, this is the third bothersome quirk with netlify dev I've experienced with your functions offering. I'd really like to use your product, and it saddens that I'm having such a hard time with these seemingly basic things

I'm on netlify-cli/2.38.0 linux-x64 node-v10.19.0

[RaeesBhatti]

@oles Can you please share an example project with this problem!

[oles]

@RaeesBhatti Sure - I'll get to it tomorrow 👍

[oles]

@RaeesBhatti Here you go: https://github.com/oles/netlify-functions-env-example

Just run netlify dev in it, verify that it reports Overriding the following env variables with .env file: API_KEY,API_SECRET.

Then open http://localhost:8888/.netlify/functions/example, and see that it is blank, and that it logs out two undefineds in the console.

They should be the values from the .env file, as accessed in the function with const {API_KEY, API_SECRET} = process.env

[RaeesBhatti]

Thanks for reporting this @oles. This was caused by a silly mistake, we've added tests to make sure that doesn't happen again: #748

[unclejustin]

🍻 Cheers for the transparency @RaeesBhatti !

[oles]

@RaeesBhatti Perfect! Thank you!

[RaeesBhatti]

A fix for this has been released in netlify-cli@2.39.0

[fjeddy]

This only listens for for variables in .env and ignores alternatives like .env.production and .env.development

[wesbos]

Yeah this is confusing as Gatsby uses the above env files, not just.env

[JLarky]

Yeah this is confusing as Gatsby uses the above env files, not just.env

yes, I was also confused by that so I created #924 hope that helps