rename ngin to rest

rest/server.go

@@ -0,0 +1,218 @@
+package rest
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"time"
+
+	"zero/core/codec"
+	"zero/core/load"
+	"zero/core/stat"
+	"zero/rest/handler"
+	"zero/rest/internal"
+	"zero/rest/internal/router"
+
+	"github.com/justinas/alice"
+)
+
+// use 1000m to represent 100%
+const topCpuUsage = 1000
+
+var ErrSignatureConfig = errors.New("bad config for Signature")
+
+type (
+	Middleware func(next http.HandlerFunc) http.HandlerFunc
+
+	server struct {
+		conf                 RtConf
+		routes               []featuredRoutes
+		unauthorizedCallback handler.UnauthorizedCallback
+		unsignedCallback     handler.UnsignedCallback
+		middlewares          []Middleware
+		shedder              load.Shedder
+		priorityShedder      load.Shedder
+	}
+)
+
+func newServer(c RtConf) *server {
+	srv := &server{
+		conf: c,
+	}
+	if c.CpuThreshold > 0 {
+		srv.shedder = load.NewAdaptiveShedder(load.WithCpuThreshold(c.CpuThreshold))
+		srv.priorityShedder = load.NewAdaptiveShedder(load.WithCpuThreshold(
+			(c.CpuThreshold + topCpuUsage) >> 1))
+	}
+
+	return srv
+}
+
+func (s *server) AddRoutes(r featuredRoutes) {
+	s.routes = append(s.routes, r)
+}
+
+func (s *server) SetUnauthorizedCallback(callback handler.UnauthorizedCallback) {
+	s.unauthorizedCallback = callback
+}
+
+func (s *server) SetUnsignedCallback(callback handler.UnsignedCallback) {
+	s.unsignedCallback = callback
+}
+
+func (s *server) Start() error {
+	return s.StartWithRouter(router.NewPatRouter())
+}
+
+func (s *server) StartWithRouter(router router.Router) error {
+	if err := s.bindRoutes(router); err != nil {
+		return err
+	}
+
+	return internal.StartHttp(s.conf.Host, s.conf.Port, router)
+}
+
+func (s *server) appendAuthHandler(fr featuredRoutes, chain alice.Chain,
+	verifier func(alice.Chain) alice.Chain) alice.Chain {
+	if fr.jwt.enabled {
+		if len(fr.jwt.prevSecret) == 0 {
+			chain = chain.Append(handler.Authorize(fr.jwt.secret,
+				handler.WithUnauthorizedCallback(s.unauthorizedCallback)))
+		} else {
+			chain = chain.Append(handler.Authorize(fr.jwt.secret,
+				handler.WithPrevSecret(fr.jwt.prevSecret),
+				handler.WithUnauthorizedCallback(s.unauthorizedCallback)))
+		}
+	}
+
+	return verifier(chain)
+}
+
+func (s *server) bindFeaturedRoutes(router router.Router, fr featuredRoutes, metrics *stat.Metrics) error {
+	verifier, err := s.signatureVerifier(fr.signature)
+	if err != nil {
+		return err
+	}
+
+	for _, route := range fr.routes {
+		if err := s.bindRoute(fr, router, metrics, route, verifier); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *server) bindRoute(fr featuredRoutes, router router.Router, metrics *stat.Metrics,
+	route Route, verifier func(chain alice.Chain) alice.Chain) error {
+	chain := alice.New(
+		handler.TracingHandler,
+		s.getLogHandler(),
+		handler.MaxConns(s.conf.MaxConns),
+		handler.BreakerHandler(route.Method, route.Path, metrics),
+		handler.SheddingHandler(s.getShedder(fr.priority), metrics),
+		handler.TimeoutHandler(time.Duration(s.conf.Timeout)*time.Millisecond),
+		handler.RecoverHandler,
+		handler.MetricHandler(metrics),
+		handler.PromMetricHandler(route.Path),
+		handler.MaxBytesHandler(s.conf.MaxBytes),
+		handler.GunzipHandler,
+	)
+	chain = s.appendAuthHandler(fr, chain, verifier)
+
+	for _, middleware := range s.middlewares {
+		chain = chain.Append(convertMiddleware(middleware))
+	}
+	handle := chain.ThenFunc(route.Handler)
+
+	return router.Handle(route.Method, route.Path, handle)
+}
+
+func (s *server) bindRoutes(router router.Router) error {
+	metrics := s.createMetrics()
+
+	for _, fr := range s.routes {
+		if err := s.bindFeaturedRoutes(router, fr, metrics); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (s *server) createMetrics() *stat.Metrics {
+	var metrics *stat.Metrics
+
+	if len(s.conf.Name) > 0 {
+		metrics = stat.NewMetrics(s.conf.Name)
+	} else {
+		metrics = stat.NewMetrics(fmt.Sprintf("%s:%d", s.conf.Host, s.conf.Port))
+	}
+
+	return metrics
+}
+
+func (s *server) getLogHandler() func(http.Handler) http.Handler {
+	if s.conf.Verbose {
+		return handler.DetailedLogHandler
+	} else {
+		return handler.LogHandler
+	}
+}
+
+func (s *server) getShedder(priority bool) load.Shedder {
+	if priority && s.priorityShedder != nil {
+		return s.priorityShedder
+	}
+	return s.shedder
+}
+
+func (s *server) signatureVerifier(signature signatureSetting) (func(chain alice.Chain) alice.Chain, error) {
+	if !signature.enabled {
+		return func(chain alice.Chain) alice.Chain {
+			return chain
+		}, nil
+	}
+
+	if len(signature.PrivateKeys) == 0 {
+		if signature.Strict {
+			return nil, ErrSignatureConfig
+		} else {
+			return func(chain alice.Chain) alice.Chain {
+				return chain
+			}, nil
+		}
+	}
+
+	decrypters := make(map[string]codec.RsaDecrypter)
+	for _, key := range signature.PrivateKeys {
+		fingerprint := key.Fingerprint
+		file := key.KeyFile
+		decrypter, err := codec.NewRsaDecrypter(file)
+		if err != nil {
+			return nil, err
+		}
+
+		decrypters[fingerprint] = decrypter
+	}
+
+	return func(chain alice.Chain) alice.Chain {
+		if s.unsignedCallback != nil {
+			return chain.Append(handler.ContentSecurityHandler(
+				decrypters, signature.Expiry, signature.Strict, s.unsignedCallback))
+		} else {
+			return chain.Append(handler.ContentSecurityHandler(
+				decrypters, signature.Expiry, signature.Strict))
+		}
+	}, nil
+}
+
+func (s *server) use(middleware Middleware) {
+	s.middlewares = append(s.middlewares, middleware)
+}
+
+func convertMiddleware(ware Middleware) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(ware(next.ServeHTTP))
+	}
+}