gatsby-node.js

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

 // You can delete this file if you're not using it

const path = require("path");

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

  const cmsPostTemplate = path.resolve(`src/templates/cmsTemplate.js`);

  return graphql(`
    {
      allMarkdownRemark(
        sort: { order: DESC, fields: [frontmatter___date] }
        limit: 1000
      ) {
        edges {
          node {
            excerpt(pruneLength: 250)
            html
            id
            frontmatter {
              date
              path
              title
            }
          }
        }
      }
    }
  `).then(result => {
    if (result.errors) {
      return Promise.reject(result.errors);
    }

    result.data.allMarkdownRemark.edges.forEach(({ node }) => {
      createPage({
        path: node.frontmatter.path,
        component: cmsPostTemplate,
        context: {}, // additional data can be passed via context
      });
    });
  });
};