gatsby-config.js

const config = require('./data/SiteConfig')

const pathPrefix = config.pathPrefix === '/' ? '' : config.pathPrefix

module.exports = {
  pathPrefix: config.pathPrefix,
  siteMetadata: {
    siteUrl: config.siteUrl + pathPrefix,
  },
  plugins: [
    {
      resolve: 'gatsby-plugin-i18n',
      options: {
        langKeyDefault: 'en',
        useLangKeyLayout: false,
      },
    },
    {
      resolve: 'gatsby-plugin-google-analytics',
      options: {
        head: true,
        trackingId: config.googleAnalyticsID,
      },
    },
    'gatsby-plugin-react-helmet',
    {
      resolve: 'gatsby-transformer-remark',
      options: {
        plugins: [
          {
            resolve: 'gatsby-remark-images',
            options: {
              maxWidth: 690,
            },
          },
          {
            resolve: 'gatsby-remark-responsive-iframe',
          },
          'gatsby-remark-prismjs',
          'gatsby-remark-copy-linked-files',
          'gatsby-remark-autolink-headers',
        ],
      },
    },
    {
      resolve: 'gatsby-plugin-nprogress',
      options: {
        color: config.themeColor,
      },
    },
    'gatsby-plugin-sharp',
    'gatsby-plugin-sitemap',
  ],
}