Ability to run graphql queries within gatsby SSR APIs

[herecydev]

I would like the ability to run graphql queries so that I can populate head attributes with some dynamic content:

exports.onRenderBody = ({ setHeadComponents }) => {
  // run query here

  setHeadComponents(...)
}

The only viable alternative is to use react-helmet and use static queries/page queries but that puts an unnecessary requirement on runtime components. Alternatively is there a way to pass data from gatsby node apis through to the ssr apis?