Customer setup for Gatsby Preview

gatsby-config.js

module.exports = {
  plugins: [
    {
      resolve: 'gatsby-source-contentful',
      options: {
        spaceId: process.env.GATSBY_CONTENTFUL_SPACE_ID || process.your.CONTENTFUL_SPACE_ID,
        accessToken: process.env.GATSBY_CONTENTFUL_ACCESS_TOKEN || process.env.CONTENTFUL_ACCESS_TOKEN,
        host: process.env.GATSBY_CONTENTFUL_HOST || process.env.CONTENTFUL_HOST
      }
    }
  ]
}