api/resolver: update resolver to enable subdomain routing (#1747)

* api/resolver: update domain / service prefix usage

* api/resolver/subdomain: implement subdomain resolver for domain resolution

* api/handler: fix tests

api/handler/http/http_test.go

@@ -58,7 +58,7 @@ func testHttp(t *testing.T, path, service, ns string) {
 		router.WithHandler("http"),
 		router.WithRegistry(r),
 		router.WithResolver(vpath.NewResolver(
-			resolver.WithNamespace(resolver.StaticNamespace(ns)),
+			resolver.WithServicePrefix(ns),
 		)),
 	)
 

api/resolver/grpc/grpc.go

@@ -9,7 +9,9 @@ import (
 	"github.com/micro/go-micro/v2/api/resolver"
 )
 
-type Resolver struct{}
+type Resolver struct {
+	opts resolver.Options
+}
 
 func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 	// /foo.Bar/Service
@@ -26,6 +28,7 @@ func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 		Host:   req.Host,
 		Method: req.Method,
 		Path:   req.URL.Path,
+		Domain: r.opts.Domain,
 	}, nil
 }
 
@@ -34,5 +37,5 @@ func (r *Resolver) String() string {
 }
 
 func NewResolver(opts ...resolver.Option) resolver.Resolver {
-	return &Resolver{}
+	return &Resolver{opts: resolver.NewOptions(opts...)}
 }

api/resolver/host/host.go

@@ -17,6 +17,7 @@ func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 		Host:   req.Host,
 		Method: req.Method,
 		Path:   req.URL.Path,
+		Domain: r.opts.Domain,
 	}, nil
 }
 

api/resolver/options.go

@@ -1,23 +1,17 @@
 package resolver
 
 import (
-	"net/http"
+	"github.com/micro/go-micro/v2/registry"
 )
 
-// NewOptions returns new initialised options
-func NewOptions(opts ...Option) Options {
-	var options Options
-	for _, o := range opts {
-		o(&options)
-	}
-
-	if options.Namespace == nil {
-		options.Namespace = StaticNamespace("go.micro")
-	}
-
-	return options
+type Options struct {
+	Handler       string
+	Domain     string
+	ServicePrefix string
 }
 
+type Option func(o *Options)
+
 // WithHandler sets the handler being used
 func WithHandler(h string) Option {
 	return func(o *Options) {
@@ -25,9 +19,29 @@ func WithHandler(h string) Option {
 	}
 }
 
-// WithNamespace sets the function which determines the namespace for a request
-func WithNamespace(n func(*http.Request) string) Option {
+// WithDomain sets the namespace option
+func WithDomain(n string) Option {
 	return func(o *Options) {
-		o.Namespace = n
+		o.Domain = n
 	}
 }
+
+// WithServicePrefix sets the ServicePrefix option
+func WithServicePrefix(p string) Option {
+	return func(o *Options) {
+		o.ServicePrefix = p
+	}
+}
+
+// NewOptions returns new initialised options
+func NewOptions(opts ...Option) Options {
+	var options Options
+	for _, o := range opts {
+		o(&options)
+	}
+	if len(options.Domain) == 0 {
+		options.Domain = registry.DefaultDomain
+	}
+
+	return options
+}

api/resolver/path/path.go

@@ -18,13 +18,13 @@ func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 	}
 
 	parts := strings.Split(req.URL.Path[1:], "/")
-	ns := r.opts.Namespace(req)
 
 	return &resolver.Endpoint{
-		Name:   ns + "." + parts[0],
+		Name:   r.opts.ServicePrefix + "." + parts[0],
 		Host:   req.Host,
 		Method: req.Method,
 		Path:   req.URL.Path,
+		Domain: r.opts.Domain,
 	}, nil
 }
 

api/resolver/resolver.go

@@ -27,18 +27,6 @@ type Endpoint struct {
 	Method string
 	// HTTP Path e.g /greeter.
 	Path string
-}
-
-type Options struct {
-	Handler   string
-	Namespace func(*http.Request) string
-}
-
-type Option func(o *Options)
-
-// StaticNamespace returns the same namespace for each request
-func StaticNamespace(ns string) func(*http.Request) string {
-	return func(*http.Request) string {
-		return ns
-	}
+	// Domain endpoint exists within
+	Domain string
 }

api/resolver/subdomain/subdomain.go

@@ -0,0 +1,86 @@
+// Package subdomain is a resolver which uses the subdomain to determine the domain to route to. It
+// offloads the endpoint resolution to a child resolver which is provided in New.
+package subdomain
+
+import (
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/micro/go-micro/v2/api/resolver"
+	"github.com/micro/go-micro/v2/logger"
+	"golang.org/x/net/publicsuffix"
+)
+
+func NewResolver(parent resolver.Resolver, opts ...resolver.Option) resolver.Resolver {
+	options := resolver.NewOptions(opts...)
+	return &Resolver{options, parent}
+}
+
+type Resolver struct {
+	opts resolver.Options
+	resolver.Resolver
+}
+
+func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
+	// resolve the endpoint using the provided resolver
+	endpoint, err := r.Resolver.Resolve(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// override the domain
+	endpoint.Domain = r.resolveDomain(req)
+
+	// return the result
+	return endpoint, nil
+}
+
+func (r *Resolver) resolveDomain(req *http.Request) string {
+	// determine the host, e.g. foobar.m3o.app
+	host := req.URL.Hostname()
+	if len(host) == 0 {
+		if h, _, err := net.SplitHostPort(req.Host); err == nil {
+			host = h // host does contain a port
+		} else if strings.Contains(err.Error(), "missing port in address") {
+			host = req.Host // host does not contain a port
+		}
+	}
+
+	// check for an ip address
+	if net.ParseIP(host) != nil {
+		return r.opts.Domain
+	}
+
+	// check for dev enviroment
+	if host == "localhost" || host == "127.0.0.1" {
+		return r.opts.Domain
+	}
+
+	// extract the top level domain plus one (e.g. 'myapp.com')
+	domain, err := publicsuffix.EffectiveTLDPlusOne(host)
+	if err != nil {
+		logger.Debugf("Unable to extract domain from %v", host)
+		return r.opts.Domain
+	}
+
+	// there was no subdomain
+	if host == domain {
+		return r.opts.Domain
+	}
+
+	// remove the domain from the host, leaving the subdomain, e.g. "staging.foo.myapp.com" => "staging.foo"
+	subdomain := strings.TrimSuffix(host, "."+domain)
+
+	// return the reversed subdomain as the namespace, e.g. "staging.foo" => "foo-staging"
+	comps := strings.Split(subdomain, ".")
+	for i := len(comps)/2 - 1; i >= 0; i-- {
+		opp := len(comps) - 1 - i
+		comps[i], comps[opp] = comps[opp], comps[i]
+	}
+	return strings.Join(comps, "-")
+}
+
+func (r *Resolver) String() string {
+	return "subdomain"
+}

api/resolver/subdomain/subdomain_test.go

@@ -0,0 +1,71 @@
+package subdomain
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+
+	"github.com/micro/go-micro/v2/api/resolver/vpath"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestResolve(t *testing.T) {
+	tt := []struct {
+		Name   string
+		Host   string
+		Result string
+	}{
+		{
+			Name:   "Top level domain",
+			Host:   "micro.mu",
+			Result: "micro",
+		},
+		{
+			Name:   "Effective top level domain",
+			Host:   "micro.com.au",
+			Result: "micro",
+		},
+		{
+			Name:   "Subdomain dev",
+			Host:   "dev.micro.mu",
+			Result: "dev",
+		},
+		{
+			Name:   "Subdomain foo",
+			Host:   "foo.micro.mu",
+			Result: "foo",
+		},
+		{
+			Name:   "Multi-level subdomain",
+			Host:   "staging.myapp.m3o.app",
+			Result: "myapp-staging",
+		},
+		{
+			Name:   "Dev host",
+			Host:   "127.0.0.1",
+			Result: "micro",
+		},
+		{
+			Name:   "Localhost",
+			Host:   "localhost",
+			Result: "micro",
+		},
+		{
+			Name:   "IP host",
+			Host:   "81.151.101.146",
+			Result: "micro",
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.Name, func(t *testing.T) {
+			r := NewResolver(vpath.NewResolver())
+			result, err := r.Resolve(&http.Request{URL: &url.URL{Host: tc.Host, Path: "foo/bar"}})
+			assert.Nil(t, err, "Expecter err to be nil")
+			if result != nil {
+				assert.Equal(t, tc.Result, result.Domain, "Expected %v but got %v", tc.Result, result.Domain)
+			}
+		})
+	}
+}

api/resolver/vpath/vpath.go

@@ -30,28 +30,31 @@ func (r *Resolver) Resolve(req *http.Request) (*resolver.Endpoint, error) {
 	parts := strings.Split(req.URL.Path[1:], "/")
 	if len(parts) == 1 {
 		return &resolver.Endpoint{
-			Name:   r.withNamespace(req, parts...),
+			Name:   r.withPrefix(parts...),
 			Host:   req.Host,
 			Method: req.Method,
 			Path:   req.URL.Path,
+			Domain: r.opts.Domain,
 		}, nil
 	}
 
 	// /v1/foo
 	if re.MatchString(parts[0]) {
 		return &resolver.Endpoint{
-			Name:   r.withNamespace(req, parts[0:2]...),
+			Name:   r.withPrefix(parts[0:2]...),
 			Host:   req.Host,
 			Method: req.Method,
 			Path:   req.URL.Path,
+			Domain: r.opts.Domain,
 		}, nil
 	}
 
 	return &resolver.Endpoint{
-		Name:   r.withNamespace(req, parts[0]),
+		Name:   r.withPrefix(parts[0]),
 		Host:   req.Host,
 		Method: req.Method,
 		Path:   req.URL.Path,
+		Domain: r.opts.Domain,
 	}, nil
 }
 
@@ -59,11 +62,12 @@ func (r *Resolver) String() string {
 	return "path"
 }
 
-func (r *Resolver) withNamespace(req *http.Request, parts ...string) string {
-	ns := r.opts.Namespace(req)
-	if len(ns) == 0 {
-		return strings.Join(parts, ".")
+// withPrefix transforms "foo" into "go.micro.api.foo"
+func (r *Resolver) withPrefix(parts ...string) string {
+	p := r.opts.ServicePrefix
+	if len(p) > 0 {
+		parts = append([]string{p}, parts...)
 	}
 
-	return strings.Join(append([]string{ns}, parts...), ".")
+	return strings.Join(parts, ".")
 }

api/router/registry/registry.go

@@ -99,7 +99,7 @@ func (r *registryRouter) process(res *registry.Result) {
 	service, err := r.rc.GetService(res.Service.Name)
 	if err != nil {
 		if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
-			logger.Errorf("unable to get service: %v", err)
+			logger.Errorf("unable to get %v service: %v", res.Service.Name, err)
 		}
 		return
 	}