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 blogPostTemplate = path.resolve(`src/templates/blog-posts.js`)

 	return graphql(`{
 		allMarkdownRemark {
 			edges {
 				node {
 					html
 					id
 					frontmatter {
 						date
 						path
 						title
 						excerpt
 						tags
 					}
 				}
 			}
 		}
 	}`)
 		.then(result => {
 			if (result.errors) {
 				return Promise.reject(result.errors)
 			}

 			const posts = result.data.allMarkdownRemark.edges

 			posts.forEach(({node}) => {
 				createPage({
 					path: node.frontmatter.path,
 					component: blogPostTemplate
 				})
 			})
 		})
 }