service.go

Documentation: github.com/emissary-ingress/emissary/v3/cmd/kat-server/services

     1  package services
     2  
     3  import (
     4  	// stdlib
     5  	"context"
     6  	"crypto/tls"
     7  	"fmt"
     8  	"net/http"
     9  	"strings"
    10  
    11  	// third party
    12  	"google.golang.org/grpc"
    13  
    14  	// first party
    15  	"github.com/datawire/dlib/dgroup"
    16  	"github.com/datawire/dlib/dhttp"
    17  	"github.com/datawire/dlib/dlog"
    18  )
    19  
    20  // Service defines a KAT backend service interface.
    21  type Service interface {
    22  	Start(context.Context) <-chan bool
    23  }
    24  
    25  type HTTPListener struct {
    26  	CleartextPort int16
    27  	TLSPort       int16
    28  	TLSCert       string
    29  	TLSKey        string
    30  }
    31  
    32  func (hl HTTPListener) Run(ctx context.Context, name string, httpHandler *http.ServeMux, grpcHandler *grpc.Server) <-chan bool {
    33  	dlog.Printf(ctx, "GRPCRLS: %s listening on cleartext :%d and tls :%d", name, hl.CleartextPort, hl.TLSPort)
    34  
    35  	cer, err := tls.LoadX509KeyPair(hl.TLSCert, hl.TLSKey)
    36  	if err != nil {
    37  		dlog.Error(ctx, err)
    38  		panic(err) // TODO: do something better
    39  	}
    40  
    41  	sc := &dhttp.ServerConfig{
    42  		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    43  			dlog.Infof(r.Context(), "handling request to %q...", r.RequestURI)
    44  			if r.ProtoMajor == 2 && strings.HasPrefix(r.Header.Get("Content-Type"), "application/grpc") {
    45  				grpcHandler.ServeHTTP(w, r)
    46  			} else {
    47  				httpHandler.ServeHTTP(w, r)
    48  			}
    49  		}),
    50  		TLSConfig: &tls.Config{
    51  			Certificates: []tls.Certificate{cer},
    52  		},
    53  	}
    54  
    55  	grp := dgroup.NewGroup(ctx, dgroup.GroupConfig{})
    56  	grp.Go("cleartext", func(ctx context.Context) error {
    57  		return sc.ListenAndServe(ctx, fmt.Sprintf(":%v", hl.CleartextPort))
    58  	})
    59  	grp.Go("tls", func(ctx context.Context) error {
    60  		return sc.ListenAndServeTLS(ctx, fmt.Sprintf(":%v", hl.TLSPort), "", "")
    61  	})
    62  
    63  	dlog.Printf(ctx, "starting %s", name)
    64  
    65  	exited := make(chan bool)
    66  	go func() {
    67  		if err := grp.Wait(); err != nil {
    68  			dlog.Error(ctx, err)
    69  			panic(err) // TODO: do something better
    70  		}
    71  		close(exited)
    72  	}()
    73  	return exited
    74  }
    75
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