SSG: Consume internal API routes inside getStaticProps

[HaNdTriX]

Is it possible the consume an internal api of a Next.js project (e.g.: pages/api/post.js) inside getStaticProps? If yes; how?

Example:

export async function getStaticProps(context) {
  // The following url must be absolute
  // but what is the correct origin/port? 
  const url = '/api/post'

  return {
    props: await fetch(url).then(res => res.json())
  }
}

Before (in getInitialProps) we had the Request object of node (ctx.req) that allowed us the retrieve this URL from some headers.

[timneutkens]

See #9524 (comment)