make getUpStream with http2 work

[nickwinger]

make getUpStream with http2 work

[nickwinger]

ok, so digging into it more i think the pool is too much for the plugin, however there is a better way i found, just mention in the docs or also a code-check that getUpStream is not working with http2.

Then to make multiple different proxy-routes work with http2, you just use more server.registers AND the contraints magic which is built into fastify (the find-my-way lib)

so in my case i want to check the content-type, so made this contraints-strategy infastify:

const contentTypeMatchContraintStrategy = {
    // strategy name for referencing in the route handler `constraints` options
    name: 'contentType',
    // storage factory for storing routes in the find-my-way route tree
    storage: function () {
      let handlers = {}
      return {
        get: (type: any) => { return handlers[type] || null },
        set: (type: any, store: any) => { handlers[type] = store }
      }
    },
    // function to get the value of the constraint from each incoming request
    deriveConstraint: (req: any, ctx: any) => {
      return req.headers['content-type']
    },
    // optional flag marking if handlers without constraints can match requests that have a value for this constraint
    mustMatchWhenDerived: true,
    // Bug not used no more
    validate: (value: unknown) => {}
  }
 
  server.addConstraintStrategy(contentTypeMatchContraintStrategy);

And then you can use it for the proxy to check the different content-type's like so:

server.register(fastifyHttpProxy, {
      http2: true,
      upstream: "http://grpc-web-server",
      httpMethods: ['DELETE', 'GET', 'HEAD', 'PATCH', 'POST', 'PUT'],
      constraints: { "contentType":"application/grpc-web+proto" },    
      disableCache: true,
      preHandler(req, reply, next) {
        // Just for logging
        console.log(`content-type match ${contentType}, forwarding to ${forwardUrl}`);  
        next();        
      }
    });
server.register(fastifyHttpProxy, {
      http2: true,
      upstream: "http://grpc-server",
      httpMethods: ['DELETE', 'GET', 'HEAD', 'PATCH', 'POST', 'PUT'],
      constraints: { "contentType":"application/grpc+proto" },    
      disableCache: true,
      preHandler(req, reply, next) {
        // Just for logging
        console.log(`content-type match ${contentType}, forwarding to ${forwardUrl}`);  
        next();        
      }
    });