gatsby-node.js

const path = require(`path`)

exports.createPages = async ({ graphql, actions: { createPage } }) => {
  const blogPostTemplate = path.resolve(`src/templates/BlogPost.js`)
  const results = await graphql(
    `
      {
        allJupyterNotebook {
          nodes {
            fields {
              slug
            }
          }
        }
      }
    `
  )
  const posts = results.data.allJupyterNotebook.nodes
  posts.forEach(post => {
    createPage({
      path: post.fields.slug,
      component: blogPostTemplate,
      context: {
        slug: post.fields.slug,
      },
    })
  })
}

exports.onCreateNode = ({ node, actions }) => {
  const { createNodeField } = actions
  if (node.internal.type === "JupyterNotebook") {
    createNodeField({
      name: "slug",
      node,
      value: node.json.metadata.title
        .split(" ")
        .map(token => token.toLowerCase())
        .join("-"),
    })
  }
}