Method call

client/rpc_client.go:79–234

(
	ctx context.Context,
	node *registry.Node,
	req Request,
	resp interface{},
	opts CallOptions,
)

}

func (r *rpcClient) call(
	ctx context.Context,
	node *registry.Node,
	req Request,
	resp interface{},
	opts CallOptions,
) error {
	address := node.Address
	logger := r.Options().Logger

	msg := &transport.Message{
		Header: make(map[string]string),
	}

	md, ok := metadata.FromContext(ctx)
	if ok {
		for k, v := range md {
			// Don't copy Micro-Topic header, that is used for pub/sub
			// this is fixes the case when the client uses the same context that
			// is received in the subscriber.
			if k == headers.Message {
				continue
			}

			msg.Header[k] = v
		}
	}

	// Set connection timeout for single requests to the server. Should be > 0
	// as otherwise requests can't be made.
	cTimeout := opts.ConnectionTimeout
	if cTimeout == 0 {
		logger.Log(log.DebugLevel, "connection timeout was set to 0, overridng to default connection timeout")

		cTimeout = DefaultConnectionTimeout
	}

	// set timeout in nanoseconds
	msg.Header["Timeout"] = fmt.Sprintf("%d", cTimeout)
	// set the content type for the request
	msg.Header["Content-Type"] = req.ContentType()
	// set the accept header
	msg.Header["Accept"] = req.ContentType()

	// setup old protocol
	reqCodec := setupProtocol(msg, node)

	// no codec specified
	if reqCodec == nil {
		var err error
		reqCodec, err = r.newCodec(req.ContentType())

		if err != nil {
			return merrors.InternalServerError("go.micro.client", err.Error())
		}
	}

	dOpts := []transport.DialOption{