What's the proper way of setting environment variable in Netlify functions?

[iamskok]

About me

• My name: Vladimir Skok
• I've used Netlify: for about 5 month

My question in a little more detail

What's the proper way of setting environment variables in netlify? I would like to be able to set different values for the variables depending on the environment.

Pseudo code:

let host;
if (process.env.GATSBY_CUSTOM_CONTEXT === 'production') {
    host = process.env.PRODUCTION_HOST
} else if (process.env.GATSBY_CUSTOM_CONTEXT === 'development') {
    host = process.env.DEVELOPMENT_HOST
}

I have tried passing env variable thru CLI, like GATSBY_CUSTOM_CONTEXT=production gatsby build and I also tried using same command with cross-env.

My other attempt used netlify.toml:

[build]
  base = "/"
  publish = "public"
  command = "yarn build"
  functions = "src/functions"

[context.production]
  [context.production.environment]
    GATSBY_CUSTOM_CONTEXT = "production"

All of these options worked with netlify dev locally, but in production GATSBY_CUSTOM_CONTEXT is always undefined.