Gatsby .env.production variables - undefined - environment-variables

Question

When building a Gatsby project I'm getting all env variables undefined in production environment.
In development everything is fine.
I have 2 similar .env.development and .env.production files.
In my gatsby-config.js I have
require('dotenv').config({
path: `.env.${process.env.NODE_ENV}`,
});
and if I console.log(process.env.NODE_ENV) during gatsby build it gives production and the variables can be accessed and logged out.
But later in code something like
return request.post(`${process.env.GEOCODING_CF_URL}/latlng`, {...});
gives request to http://localhost:9000/ru/undefined/latlng.
What am I doing wrong and how this issue can be fixed?
UPDATE:
When I run gatsby build - process.env.NODE_ENV is production
When I run gatsby serve - process.env.NODE_ENV is undefined
If this can help in any way.

Answer 1

If you use environment variables in node you don't need a prefix (like in your gatsby-config.js). However, if you need to use them in a component or a page you must add GATSBY_ as a prefix, so GEOCODING_CF_URL should be GATSBY_GEOCODING_CF_URL

Answer 2

For me, NODE_ENV=production yarn gatsby serve did the trick.

Answer 3

https://www.gatsbyjs.com/docs/how-to/local-development/environment-variables/
Accessing Environment Variables in the browser.
By default, environment variables are only available in Node.js code and are not available in the browser as some variables should be kept secret and not exposed to anyone visiting the site.
To expose a variable in the browser, you must preface its name with GATSBY_. So GATSBY_API_URL will be available in browser code but API_KEY will not.
Variables are set when JavaScript is compiled so when the development server is started or you build your site.
src/pages/index.js
Copysrc/pages/index.js: copy code to clipboard
import React, { useState, useEffect } from "react"
function App() {
const [data, setData] = useState()
useEffect(async () => {
const result = await fetch(
`${process.env.GATSBY_API_URL}/users`
).then(res => res.json())
setData(result.data)
})
return (
<ul>
{data.map(user => (
<li key={user.id}>
<a href={user.url}>{user.name}</a>
</li>
))}
</ul>
)
}
export default App