convert website from hugo to gatsby (#1369)

website/gatsby-node.js

@@ -0,0 +1,91 @@
+const path = require('path');
+const { createFilePath } = require('gatsby-source-filesystem');
+
+exports.createPages = async ({ graphql, boundActionCreators }) => {
+  const { createPage } = boundActionCreators;
+
+  const docPage = path.resolve('./src/templates/doc-page.js');
+  const blogPost = path.resolve('./src/templates/blog-post.js');
+
+  // get all markdown with a frontmatter path field and title
+  const allMarkdown = await graphql(`
+    {
+      allMarkdownRemark(filter: { frontmatter: { title: { ne: null } } }) {
+        edges {
+          node {
+            fields {
+              slug
+            }
+            frontmatter {
+              title
+            }
+          }
+        }
+      }
+    }
+  `);
+
+  if (allMarkdown.errors) {
+    console.error(allMarkdown.errors);
+    throw Error(allMarkdown.errors);
+  }
+
+  allMarkdown.data.allMarkdownRemark.edges.forEach(({ node }) => {
+    const { slug } = node.fields;
+
+    let template = docPage;
+
+    if (slug.includes('blog/')) {
+      template = blogPost;
+    }
+
+    createPage({
+      path: slug,
+      component: template,
+      context: {
+        slug
+      }
+    });
+  });
+};
+
+const pad = n => (n >= 10 ? n : `0${n}`);
+
+exports.onCreateNode = ({ node, boundActionCreators, getNode }) => {
+  const { createNodeField } = boundActionCreators;
+
+  if (node.internal.type === 'MarkdownRemark') {
+    const value = createFilePath({ node, getNode });
+    const { relativePath } = getNode(node.parent);
+
+    let slug = value;
+
+    if (relativePath.includes('blog/')) {
+      const date = new Date(node.frontmatter.date);
+      const year = date.getFullYear();
+      const month = date.getMonth() + 1;
+      const filename = path.basename(relativePath, '.md');
+      slug = `/blog/${year}/${pad(month)}/${filename}`;
+
+      createNodeField({
+        node,
+        name: 'date',
+        value: date.toJSON()
+      });
+    }
+
+    // used for doc posts
+    createNodeField({
+      node,
+      name: 'slug',
+      value: slug
+    });
+
+    // used to create GitHub edit link
+    createNodeField({
+      node,
+      name: 'path',
+      value: relativePath
+    });
+  }
+};