built-time-fetch.js

// gatsby-node.js file

const axios = require('axios')
require('dotenv').config({
  path: `.env.${process.env.NODE_ENV}`, // this dotenv config gives access to process.env object
})

const getCoffeeShops = async () => {
  const shops = await axios.get(process.env.GATSBY_COFFEE_SHOPS_URL)
  return shops.data.Items
}

exports.onCreatePage = async ({ page, actions }) => {
  if (page.path === '/coffee' || page.path === '/coffee/') {
    const { createPage, deletePage } = actions
    deletePage(page)

    const coffeeShops = await getCoffeeShops()

    createPage({
      ...page,
      context: {
        ...page.context,
        coffeeShops,
      },
    })
  }
}