Cant seem to target the correct build in Gatsby Cloud

I recently set up a Gatsby Cloud account for my Gatsby app. I currently have a github workflow that deploys the prod build to AWS, I want to move away from AWS and use G.C.

I have a prod backend and a staging backend, both WordPress.

My goal is:

• Whenever I put up a PR, I can see that preview-build targeting/pointing to my staging backend
• When I merge a PR into master I want the prod build to point to my prod backend

Once I can accomplish the above, I can then update my dns and point to the GC server. Allowing me to leave AWS, but giving me a prod instance and an ephemeral staging instance.

Problem I am facing:

• Whether it is a preview build from a PR or a "prod" build (merge to master), G.C. seems to only use my development env values.
• I dont see a way to kick off a specific build script based on a G.C. env var, I am currently using GATSBY_IS_PREVIEW but it seems to be true in both build scenarios

Here is my gatsby-config:

let activeEnv = process.env.GATSBY_IS_PREVIEW ? "development" : process.env.NODE_ENV || "development";

require("dotenv").config({
  path: `.env.${activeEnv}`,
});
console.log(`** Build Env: '${activeEnv}'`);
console.log("** BACKEND URL:", process.env.GATSBY_GRAPHQL_URL);
console.log("** GATSBY_STRIPE_KEY:", process.env.GATSBY_STRIPE_KEY.substring(0, 10));
console.log("** GATSBY_STRIPE_SECRET_KEY:", process.env.GATSBY_STRIPE_SECRET_KEY.substring(0, 10));

Any help is greatly appreciated.

>Solution :

You can use the BRANCH env var, like this:

let activeEnv = process.env.BRANCH === 'master' ? "production" : "development";
require("dotenv").config({
  path: `.env.${activeEnv}`,
});

Gatsby Cloud Env Vars