title: How do I get the current url in Gatsby?
body: <p>I am currently creating share buttons with Gatsby and would like to share content based on the current url, which changes depending on the environment and the current page. With GoHugo this can be called with <code>{{ .Permalink }}</code>. Does anyone know how to do this with Gatsby?</p>
  
  <p>I have a ShareButtons component, which is a child of BlogPostTemplate.</p>