gatsby-node.js

const ExtractTextPlugin = require('extract-text-webpack-plugin');
const path = require('path');

exports.modifyWebpackConfig = ({ config, stage }) => {
  config.merge({
    resolve: {
      alias: {
        '../../theme.config': path.join(__dirname, 'src/semantic/theme.config'),
      },
    },
  });

  return config;
};

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

  const blogPostTemplate = path.resolve('src/templates/blog.js');

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

    if (!result.data || !result.data.allMarkdownRemark) return false;

    result.data.allMarkdownRemark.edges.forEach(({ node }) => {
      createPage({
        path: node.frontmatter.path,
        component: blogPostTemplate,
        context: {},
      });
    });
  });
};