selector: use custom domain (#1760)

* util/wrapper: improve auth errors

* client: add network call option

* client/selector: add domain select option

* client/grpc: pass network option to selector

client/grpc/grpc.go

@@ -84,8 +84,14 @@ func (g *grpcClient) next(request client.Request, opts client.CallOptions) (sele
 		}, nil
 	}
 
+	// if the network was set, pass it to the selector
+	sopts := opts.SelectOptions
+	if len(opts.Network) > 0 {
+		sopts = append(sopts, selector.WithDomain(opts.Network))
+	}
+
 	// get next nodes from the selector
-	next, err := g.opts.Selector.Select(service, opts.SelectOptions...)
+	next, err := g.opts.Selector.Select(service, sopts...)
 	if err != nil {
 		if err == selector.ErrNotFound {
 			return nil, errors.InternalServerError("go.micro.client", "service %s: %s", service, err.Error())

client/options.go

@@ -64,6 +64,8 @@ type CallOptions struct {
 	ServiceToken bool
 	// Duration to cache the response for
 	CacheExpiry time.Duration
+	// Network to lookup the route within
+	Network string
 
 	// Middleware for low level call func
 	CallWrappers []CallWrapper
@@ -338,6 +340,13 @@ func WithCache(c time.Duration) CallOption {
 	}
 }
 
+// WithNetwork is a CallOption which sets the network attribute
+func WithNetwork(n string) CallOption {
+	return func(o *CallOptions) {
+		o.Network = n
+	}
+}
+
 func WithMessageContentType(ct string) MessageOption {
 	return func(o *MessageOptions) {
 		o.ContentType = ct

client/selector/default.go

@@ -38,14 +38,26 @@ func (c *registrySelector) Options() Options {
 }
 
 func (c *registrySelector) Select(service string, opts ...SelectOption) (Next, error) {
-	sopts := SelectOptions{
-		Strategy: c.so.Strategy,
-	}
-
+	sopts := SelectOptions{Strategy: c.so.Strategy}
 	for _, opt := range opts {
 		opt(&sopts)
 	}
 
+	// a specific domain was requested, only lookup the services in that domain
+	if len(sopts.Domain) > 0 {
+		services, err := c.rc.GetService(service, registry.GetDomain(sopts.Domain))
+		if err != nil && err != registry.ErrNotFound {
+			return nil, err
+		}
+		for _, filter := range sopts.Filters {
+			services = filter(services)
+		}
+		if len(services) == 0 {
+			return nil, ErrNoneAvailable
+		}
+		return sopts.Strategy(services), nil
+	}
+
 	// get the service. Because the service could be running in the current or the default domain,
 	// we call both. For example, go.micro.service.foo could be running in the services current domain,
 	// however the runtime (go.micro.runtime) will always be run in the default domain.

client/selector/options.go

@@ -21,6 +21,7 @@ type Options struct {
 type SelectOptions struct {
 	Filters  []Filter
 	Strategy Strategy
+	Domain   string
 
 	// Other options for implementations of the interface
 	// can be stored in a context
@@ -68,3 +69,10 @@ func WithStrategy(fn Strategy) SelectOption {
 		o.Strategy = fn
 	}
 }
+
+// WithDomain sets the registry domain to use for the selection
+func WithDomain(d string) SelectOption {
+	return func(o *SelectOptions) {
+		o.Domain = d
+	}
+}

util/wrapper/wrapper.go

@@ -222,10 +222,10 @@ func AuthHandler(fn func() auth.Auth) server.HandlerWrapper {
 				ctx = metadata.Set(ctx, "Micro-Namespace", ns)
 			}
 
-			// Check the issuer matches the services namespace. TODO: Stop allowing go.micro to access
+			// Check the issuer matches the services namespace. TODO: Stop allowing micro to access
 			// any namespace and instead check for the server issuer.
 			if account != nil && account.Issuer != ns && account.Issuer != "micro" {
-				return errors.Forbidden(req.Service(), "Account was not issued by %v", ns)
+				return errors.Forbidden(req.Service(), "Account was issued by %v, not %v", account.Issuer, ns)
 			}
 
 			// construct the resource