Dynamic auth tokens for Websockets with Graphql Subscriptions

apollo_ws_subscription_graphql_auth.js

const subscriptionMiddleware = {
  applyMiddleware: function(options, next) {
    // Get the current context
    const context = options.getContext().graphqlContext;
    // set it on the `options` which will be passed to the websocket with Apollo 
    // Server it becomes: `ApolloServer({contetx: ({payload}) => (returns options)
    options.authorization = context.authorization;
    next()
  },
};

const server = new ApolloServer({
  context: ({connection, payload, req}) => {
    // whatever you return here can be accessed from the middleware of the SubscriptionMiddleware with
    // applyMiddleware: (options, next) => options.getContext()
    return {authorization: payload.authorization};
  },
});

const link = new WebSocketLink({
    uri: WS_URL,
    webSocketImpl: WebSocket,
    options: {
        reconnect: true,
    }
});

link.subscriptionClient.use([subscriptionMiddleware]);