feat(entrypoint): implement short link #177

- Added ShortLinkMatcher to handle short link routing.
- Integrated short link handling in Entrypoint.
- Introduced tests for short link matching and dispatching.
- Configured default domain suffix for subdomain aliases.

internal/common/env.go

@@ -13,6 +13,8 @@ var (
 	IsDebug = env.GetEnvBool("DEBUG", IsTest)
 	IsTrace = env.GetEnvBool("TRACE", false) && IsDebug
 
+	ShortLinkPrefix = env.GetEnvString("SHORTLINK_PREFIX", "go")
+
 	ProxyHTTPAddr,
 	ProxyHTTPHost,
 	ProxyHTTPPort,

internal/config/state.go

@@ -3,6 +3,8 @@ package config
 import (
 	"bytes"
 	"context"
+	"crypto/tls"
+	"crypto/x509"
 	"fmt"
 	"iter"
 	"net/http"
@@ -134,6 +136,10 @@ func (state *state) EntrypointHandler() http.Handler {
 	return &state.entrypoint
 }
 
+func (state *state) Entrypoint() *entrypoint.Entrypoint {
+	return &state.entrypoint
+}
+
 // AutoCertProvider returns the autocert provider.
 //
 // If the autocert provider is not configured, it returns nil.
@@ -191,18 +197,52 @@ func (state *state) initAccessLogger() error {
 }
 
 func (state *state) initEntrypoint() error {
-	epCfg := state.Entrypoint
+	epCfg := state.Config.Entrypoint
 	matchDomains := state.MatchDomains
 
 	state.entrypoint.SetFindRouteDomains(matchDomains)
 	state.entrypoint.SetNotFoundRules(epCfg.Rules.NotFound)
 
+	if len(matchDomains) > 0 {
+		state.entrypoint.ShortLinkMatcher().SetDefaultDomainSuffix(matchDomains[0])
+	}
+
+	if state.autocertProvider != nil {
+		if domain := getAutoCertDefaultDomain(state.autocertProvider); domain != "" {
+			state.entrypoint.ShortLinkMatcher().SetDefaultDomainSuffix("." + domain)
+		}
+	}
+
 	errs := gperr.NewBuilder("entrypoint error")
 	errs.Add(state.entrypoint.SetMiddlewares(epCfg.Middlewares))
 	errs.Add(state.entrypoint.SetAccessLogger(state.task, epCfg.AccessLog))
 	return errs.Error()
 }
 
+func getAutoCertDefaultDomain(p *autocert.Provider) string {
+	if p == nil {
+		return ""
+	}
+	cert, err := tls.LoadX509KeyPair(p.GetCertPath(), p.GetKeyPath())
+	if err != nil || len(cert.Certificate) == 0 {
+		return ""
+	}
+	x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		return ""
+	}
+
+	domain := x509Cert.Subject.CommonName
+	if domain == "" && len(x509Cert.DNSNames) > 0 {
+		domain = x509Cert.DNSNames[0]
+	}
+	domain = strings.TrimSpace(domain)
+	if after, ok := strings.CutPrefix(domain, "*."); ok {
+		domain = after
+	}
+	return strings.ToLower(domain)
+}
+
 func (state *state) initMaxMind() error {
 	maxmindCfg := state.Providers.MaxMind
 	if maxmindCfg != nil {

internal/config/types/state.go

@@ -6,6 +6,7 @@ import (
 	"iter"
 	"net/http"
 
+	"github.com/yusing/godoxy/internal/entrypoint"
 	"github.com/yusing/godoxy/internal/types"
 	"github.com/yusing/goutils/server"
 	"github.com/yusing/goutils/synk"
@@ -22,6 +23,7 @@ type State interface {
 	Value() *Config
 
 	EntrypointHandler() http.Handler
+	Entrypoint() *entrypoint.Entrypoint
 	AutoCertProvider() server.CertProvider
 
 	LoadOrStoreProvider(key string, value types.RouteProvider) (actual types.RouteProvider, loaded bool)

internal/entrypoint/entrypoint.go

@@ -6,6 +6,7 @@ import (
 	"sync/atomic"
 
 	"github.com/rs/zerolog/log"
+	"github.com/yusing/godoxy/internal/common"
 	entrypoint "github.com/yusing/godoxy/internal/entrypoint/types"
 	"github.com/yusing/godoxy/internal/logging/accesslog"
 	"github.com/yusing/godoxy/internal/net/gphttp/middleware"
@@ -21,6 +22,7 @@ type Entrypoint struct {
 	notFoundHandler http.Handler
 	accessLogger    accesslog.AccessLogger
 	findRouteFunc   func(host string) types.HTTPRoute
+	shortLinkTree   *ShortLinkMatcher
 }
 
 // nil-safe
@@ -34,9 +36,14 @@ func init() {
 func NewEntrypoint() Entrypoint {
 	return Entrypoint{
 		findRouteFunc: findRouteAnyDomain,
+		shortLinkTree: newShortLinkTree(),
 	}
 }
 
+func (ep *Entrypoint) ShortLinkMatcher() *ShortLinkMatcher {
+	return ep.shortLinkTree
+}
+
 func (ep *Entrypoint) SetFindRouteDomains(domains []string) {
 	if len(domains) == 0 {
 		ep.findRouteFunc = findRouteAnyDomain
@@ -104,6 +111,8 @@ func (ep *Entrypoint) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		} else {
 			route.ServeHTTP(w, r)
 		}
+	case ep.tryHandleShortLink(w, r):
+		return
 	case ep.notFoundHandler != nil:
 		ep.notFoundHandler.ServeHTTP(w, r)
 	default:
@@ -111,6 +120,22 @@ func (ep *Entrypoint) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func (ep *Entrypoint) tryHandleShortLink(w http.ResponseWriter, r *http.Request) (handled bool) {
+	host := r.Host
+	if before, _, ok := strings.Cut(host, ":"); ok {
+		host = before
+	}
+	if strings.EqualFold(host, common.ShortLinkPrefix) {
+		if ep.middleware != nil {
+			ep.middleware.ServeHTTP(ep.shortLinkTree.ServeHTTP, w, r)
+		} else {
+			ep.shortLinkTree.ServeHTTP(w, r)
+		}
+		return true
+	}
+	return false
+}
+
 func (ep *Entrypoint) serveNotFound(w http.ResponseWriter, r *http.Request) {
 	// Why use StatusNotFound instead of StatusBadRequest or StatusBadGateway?
 	// On nginx, when route for domain does not exist, it returns StatusBadGateway.

internal/entrypoint/shortlink.go

@@ -0,0 +1,110 @@
+package entrypoint
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/puzpuzpuz/xsync/v4"
+)
+
+type ShortLinkMatcher struct {
+	defaultDomainSuffix string // e.g. ".example.com"
+
+	fqdnRoutes      *xsync.Map[string, string] // "app" -> "app.example.com"
+	subdomainRoutes *xsync.Map[string, struct{}]
+}
+
+func newShortLinkTree() *ShortLinkMatcher {
+	return &ShortLinkMatcher{
+		fqdnRoutes:      xsync.NewMap[string, string](),
+		subdomainRoutes: xsync.NewMap[string, struct{}](),
+	}
+}
+
+func (st *ShortLinkMatcher) SetDefaultDomainSuffix(suffix string) {
+	if !strings.HasPrefix(suffix, ".") {
+		suffix = "." + suffix
+	}
+	st.defaultDomainSuffix = suffix
+}
+
+func (st *ShortLinkMatcher) AddRoute(alias string) {
+	alias = strings.TrimSpace(alias)
+	if alias == "" {
+		return
+	}
+
+	if strings.Contains(alias, ".") { // FQDN alias
+		st.fqdnRoutes.Store(alias, alias)
+		key, _, _ := strings.Cut(alias, ".")
+		if key != "" {
+			if _, ok := st.subdomainRoutes.Load(key); !ok {
+				if _, ok := st.fqdnRoutes.Load(key); !ok {
+					st.fqdnRoutes.Store(key, alias)
+				}
+			}
+		}
+		return
+	}
+
+	// subdomain alias + defaultDomainSuffix
+	if st.defaultDomainSuffix == "" {
+		return
+	}
+	st.subdomainRoutes.Store(alias, struct{}{})
+}
+
+func (st *ShortLinkMatcher) DelRoute(alias string) {
+	alias = strings.TrimSpace(alias)
+	if alias == "" {
+		return
+	}
+
+	if strings.Contains(alias, ".") {
+		st.fqdnRoutes.Delete(alias)
+		key, _, _ := strings.Cut(alias, ".")
+		if key != "" {
+			if target, ok := st.fqdnRoutes.Load(key); ok && target == alias {
+				st.fqdnRoutes.Delete(key)
+			}
+		}
+		return
+	}
+
+	st.subdomainRoutes.Delete(alias)
+}
+
+func (st *ShortLinkMatcher) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	path := r.URL.EscapedPath()
+	trim := strings.TrimPrefix(path, "/")
+	key, rest, _ := strings.Cut(trim, "/")
+	if key == "" {
+		http.Error(w, "short link key is required", http.StatusBadRequest)
+		return
+	}
+	if rest != "" {
+		rest = "/" + rest
+	} else {
+		rest = "/"
+	}
+
+	targetHost := ""
+	if strings.Contains(key, ".") {
+		targetHost, _ = st.fqdnRoutes.Load(key)
+	} else if target, ok := st.fqdnRoutes.Load(key); ok {
+		targetHost = target
+	} else if _, ok := st.subdomainRoutes.Load(key); ok && st.defaultDomainSuffix != "" {
+		targetHost = key + st.defaultDomainSuffix
+	}
+
+	if targetHost == "" {
+		http.Error(w, "short link not found", http.StatusNotFound)
+		return
+	}
+
+	targetURL := "https://" + targetHost + rest
+	if q := r.URL.RawQuery; q != "" {
+		targetURL += "?" + q
+	}
+	http.Redirect(w, r, targetURL, http.StatusTemporaryRedirect)
+}

internal/entrypoint/shortlink_test.go

@@ -0,0 +1,194 @@
+package entrypoint_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/yusing/godoxy/internal/common"
+	. "github.com/yusing/godoxy/internal/entrypoint"
+)
+
+func TestShortLinkMatcher_FQDNAlias(t *testing.T) {
+	ep := NewEntrypoint()
+	matcher := ep.ShortLinkMatcher()
+	matcher.AddRoute("app.domain.com")
+
+	t.Run("exact path", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.domain.com/", w.Header().Get("Location"))
+	})
+
+	t.Run("with path remainder", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app/foo/bar", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.domain.com/foo/bar", w.Header().Get("Location"))
+	})
+
+	t.Run("with query", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app/foo?x=y&z=1", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.domain.com/foo?x=y&z=1", w.Header().Get("Location"))
+	})
+}
+
+func TestShortLinkMatcher_SubdomainAlias(t *testing.T) {
+	ep := NewEntrypoint()
+	matcher := ep.ShortLinkMatcher()
+	matcher.SetDefaultDomainSuffix(".example.com")
+	matcher.AddRoute("app")
+
+	t.Run("exact path", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.example.com/", w.Header().Get("Location"))
+	})
+
+	t.Run("with path remainder", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app/foo/bar", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.example.com/foo/bar", w.Header().Get("Location"))
+	})
+}
+
+func TestShortLinkMatcher_NotFound(t *testing.T) {
+	ep := NewEntrypoint()
+	matcher := ep.ShortLinkMatcher()
+	matcher.SetDefaultDomainSuffix(".example.com")
+	matcher.AddRoute("app")
+
+	t.Run("missing key", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusBadRequest, w.Code)
+	})
+
+	t.Run("unknown key", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/unknown", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+}
+
+func TestShortLinkMatcher_AddDelRoute(t *testing.T) {
+	ep := NewEntrypoint()
+	matcher := ep.ShortLinkMatcher()
+	matcher.SetDefaultDomainSuffix(".example.com")
+
+	matcher.AddRoute("app1")
+	matcher.AddRoute("app2.domain.com")
+
+	t.Run("both routes work", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app1", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app1.example.com/", w.Header().Get("Location"))
+
+		req = httptest.NewRequest("GET", "/app2.domain.com", nil)
+		w = httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app2.domain.com/", w.Header().Get("Location"))
+	})
+
+	t.Run("delete route", func(t *testing.T) {
+		matcher.DelRoute("app1")
+
+		req := httptest.NewRequest("GET", "/app1", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+		assert.Equal(t, http.StatusNotFound, w.Code)
+
+		req = httptest.NewRequest("GET", "/app2.domain.com", nil)
+		w = httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app2.domain.com/", w.Header().Get("Location"))
+	})
+}
+
+func TestShortLinkMatcher_NoDefaultDomainSuffix(t *testing.T) {
+	ep := NewEntrypoint()
+	matcher := ep.ShortLinkMatcher()
+	// no SetDefaultDomainSuffix called
+
+	t.Run("subdomain alias ignored", func(t *testing.T) {
+		matcher.AddRoute("app")
+
+		req := httptest.NewRequest("GET", "/app", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+
+	t.Run("FQDN alias still works", func(t *testing.T) {
+		matcher.AddRoute("app.domain.com")
+
+		req := httptest.NewRequest("GET", "/app.domain.com", nil)
+		w := httptest.NewRecorder()
+		matcher.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.domain.com/", w.Header().Get("Location"))
+	})
+}
+
+func TestEntrypoint_ShortLinkDispatch(t *testing.T) {
+	ep := NewEntrypoint()
+	ep.ShortLinkMatcher().SetDefaultDomainSuffix(".example.com")
+	ep.ShortLinkMatcher().AddRoute("app")
+
+	t.Run("shortlink host", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app", nil)
+		req.Host = common.ShortLinkPrefix
+		w := httptest.NewRecorder()
+		ep.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.example.com/", w.Header().Get("Location"))
+	})
+
+	t.Run("shortlink host with port", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app", nil)
+		req.Host = common.ShortLinkPrefix + ":8080"
+		w := httptest.NewRecorder()
+		ep.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusTemporaryRedirect, w.Code)
+		assert.Equal(t, "https://app.example.com/", w.Header().Get("Location"))
+	})
+
+	t.Run("normal host", func(t *testing.T) {
+		req := httptest.NewRequest("GET", "/app", nil)
+		req.Host = "app.example.com"
+		w := httptest.NewRecorder()
+		ep.ServeHTTP(w, req)
+
+		// Should not redirect, should try normal route lookup (which will 404)
+		assert.NotEqual(t, http.StatusTemporaryRedirect, w.Code)
+	})
+}

internal/net/gphttp/middleware/errorpage/error_page.go

@@ -32,6 +32,9 @@ func setup() {
 }
 
 func GetStaticFile(filename string) ([]byte, bool) {
+	if common.IsTest {
+		return nil, false
+	}
 	setupOnce.Do(setup)
 	return fileContentMap.Load(filename)
 }

internal/route/fileserver.go

@@ -6,6 +6,7 @@ import (
 	"path"
 	"path/filepath"
 
+	config "github.com/yusing/godoxy/internal/config/types"
 	"github.com/yusing/godoxy/internal/logging/accesslog"
 	gphttp "github.com/yusing/godoxy/internal/net/gphttp"
 	"github.com/yusing/godoxy/internal/net/gphttp/middleware"
@@ -124,8 +125,14 @@ func (s *FileServer) Start(parent task.Parent) gperr.Error {
 	}
 
 	routes.HTTP.Add(s)
+	if state := config.WorkingState.Load(); state != nil {
+		state.Entrypoint().ShortLinkMatcher().AddRoute(s.Alias)
+	}
 	s.task.OnFinished("remove_route_from_http", func() {
 		routes.HTTP.Del(s)
+		if state := config.WorkingState.Load(); state != nil {
+			state.Entrypoint().ShortLinkMatcher().DelRoute(s.Alias)
+		}
 	})
 	return nil
 }

internal/route/reverse_proxy.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/yusing/godoxy/agent/pkg/agent"
 	"github.com/yusing/godoxy/agent/pkg/agentproxy"
+	config "github.com/yusing/godoxy/internal/config/types"
 	"github.com/yusing/godoxy/internal/idlewatcher"
 	"github.com/yusing/godoxy/internal/logging/accesslog"
 	gphttp "github.com/yusing/godoxy/internal/net/gphttp"
@@ -166,8 +167,14 @@ func (r *ReveseProxyRoute) Start(parent task.Parent) gperr.Error {
 		r.addToLoadBalancer(parent)
 	} else {
 		routes.HTTP.Add(r)
-		r.task.OnCancel("remove_route_from_http", func() {
+		if state := config.WorkingState.Load(); state != nil {
+			state.Entrypoint().ShortLinkMatcher().AddRoute(r.Alias)
+		}
+		r.task.OnCancel("remove_route", func() {
 			routes.HTTP.Del(r)
+			if state := config.WorkingState.Load(); state != nil {
+				state.Entrypoint().ShortLinkMatcher().DelRoute(r.Alias)
+			}
 		})
 	}
 	return nil
@@ -208,8 +215,14 @@ func (r *ReveseProxyRoute) addToLoadBalancer(parent task.Parent) {
 		}
 		linked.SetHealthMonitor(lb)
 		routes.HTTP.AddKey(cfg.Link, linked)
+		if state := config.WorkingState.Load(); state != nil {
+			state.Entrypoint().ShortLinkMatcher().AddRoute(cfg.Link)
+		}
 		r.task.OnFinished("remove_loadbalancer_route", func() {
 			routes.HTTP.DelKey(cfg.Link)
+			if state := config.WorkingState.Load(); state != nil {
+				state.Entrypoint().ShortLinkMatcher().DelRoute(cfg.Link)
+			}
 		})
 		lbLock.Unlock()
 	}