How to propagate Request Header using SOFA plugin to downstream service

[didos36]

I'm currently call SOFA REST endpoint and providing additional HTTP headers (authorisation etc), and I want to attached those headers to downstream http sources. Do you know how to achieve this please?
By using "headers" in graphql queries its fine

[EmrysMyrddin]

Hi! Thank you for reaching out and sorry for the response delay here.

I'm not sure I understand your question. What I understood is you have a graphql-yoga server with a SOFA plugin which exposes your schema as a REST endpoint. And now you want to forward some headers from the request made on the REST endpoint to the APIs you are calling in your resolvers ?

If this is the case, in Yoga, you always have access to the underlying HTTP request in the GraphQL context. So you can probably do something like this to forward all headers:

import { createSchema, createYoga } from 'graphql-yoga';

const schema = createSchema({
  typeDefs: /* GraphQL */`
    type Query {
      hello: String
    }
  `,
  resolvers: {
    hello: (_parent, _args, { request }) => {
      const response = await fetch('downstream-api.com/some/url', {
        // Keep in mind that ALL headers will be forwarded, you probably want to filter some headers out
        headers: request.headers
      })
      return response.text()
    }
  }
})

const yoga = createYoga({
  schema,
  plugins: [
    useSofa({
      basePath: '/rest',
    }),
  ],
})

You can even make a custom "fetcher" which already have all headers set to avoid duplicating this everywhere in your resolvers:

import { createSchema, createYoga } from 'graphql-yoga';

const schema = createSchema({
  typeDefs: /* GraphQL */`
    type Query {
      hello: String
    }
  `,
  resolvers: {
    hello: (_parent, _args, { fetchAPI }) => {
      const response = await fetchAPI('/some/url')
      return response.text()
    }
  }
})

const baseApiUrl = 'your-downstream-api.com/v1'

const yoga = createYoga({
  schema,
  context: ({ request }) => ({
    fetchAPI: (url: string, options: RequestInit) => fetch(
      `${baseApiUrl}${url}`,
      {
        headers: request.headers,
        ...options
      },
    )
  }),
  plugins: [
    useSofa({
      basePath: '/rest',
    }),
  ],
})

[didos36]

Thanks a lot for your answer.

I'm newbie, so forgive me if i'm telling you stupid stuff :)

Actually I'm using graphql mesh. Using direct call to /graphql, I can access request header, but by using sofa plugin, its somehow "lost".
I've checked a bit and in sofa plugin, and in this piece of code:

async  context(serverContext: YogaInitialContext) {
          const enveloped = getEnveloped(serverContext);
          const request = requestByContext.get(serverContext);
          const contextValue = await enveloped.contextFactory({ request });
          envelopedByContext.set(contextValue as YogaInitialContext, enveloped);
          return contextValue;
        }

more const request = requestByContext.get(serverContext); is returning nothing because the serverContext was changed to a new one in sofaHandler.

Could it be the problem?

[EmrysMyrddin]

Good catch, probably related yes!

[EmrysMyrddin]

Can you share your config file ? So I can try to reproduce on my side and see if there is a workaround or if this requires you to wait for a fix ?

[RaoHarshith]

@EmrysMyrddin I am also running into exact same issue where the headers are not passed. the .meshrc.yml files has below settings for Sofa :-

 - sofa:
      basePath: /rest
      swaggerUI:
        endpoint: /swagger
      info:
        title: "My REST API"
        version: "1.0.0"

[EmrysMyrddin]

Can you open an issue? It will be easier to track than in a discution