gatsby-node.js

/**
 * Implement Gatsby's Node APIs in this file.
 *
 * See: https://www.gatsbyjs.org/docs/node-apis/
 */

const path = require(`path`);

exports.createPages = ({ graphql, actions }) => {
  const { createPage } = actions;

  return graphql(
    `{
      allMdx {
        edges {
          node {
            id
            parent {
              ... on File {
                name
                sourceInstanceName
              }
            }
            body
          }
        }
      }
    }`
    )
    .then(result => {
      if (result.errors) {
        console.log(result.errors);
        throw result.errors;
      }
      // Create blog posts pages.
      result.data.allMdx.edges
        .forEach(({ node }) => {
          const { sourceInstanceName } = node.parent

          createPage({
            path: `/${sourceInstanceName}/${node.parent.name}`,
            component: path.resolve(`./src/templates/${sourceInstanceName}-content.js`),
            context: { 
              id: node.id 
            }
          });
      });
    })
};