gatsby-node.js

const path = require('path');
const { GraphQLClient } = require(`graphql-request`);
const parseGHUrl = require(`parse-github-url`);

/**
 * Used to gather repo details data
 */
const githubApiClient = process.env.GITHUB_TOKEN
  ? new GraphQLClient(`https://api.github.com/graphql`, {
      headers: {
        authorization: `Bearer ${process.env.GITHUB_TOKEN}`,
      },
    })
  : console.log('GITHUB TOKEN NOT FOUND!')

exports.onCreateNode = async ({ node, actions }) => {
  const { createNodeField } = actions;

  /**
   * Fetch additional data from Github for repos fetch from CMS
   */
  switch (node.internal.type) {
    case 'ContentfulRepoEntry': {
      const repoMeta = node.github ? parseGHUrl(node.github) : null; // check if github url is provided
      const repoData = await ( repoMeta 
        ? githubApiClient.request(`
          query {
            repository(owner:"${repoMeta.owner}", name:"${repoMeta.name}") {
              name
              stargazers {
                totalCount
              }
              createdAt
            }
          }
        `)
        : null
      );

      /**
       * Add field with data to repo's Node
       */
      createNodeField({
        node,
        name: 'githubData',
        value: repoData,
      })
    }
  }
}

exports.createPages = async ({ graphql, actions }) => {
  const { createPage } = actions;
  // Create pages here using data fetched durin 'onCreateNode'
};