Files
nginx-logtail/cmd/aggregator/main.go

82 lines
2.0 KiB
Go

package main
import (
"context"
"flag"
"log"
"net"
"os"
"os/signal"
"strings"
"syscall"
pb "git.ipng.ch/ipng/nginx-logtail/proto/logtailpb"
"google.golang.org/grpc"
)
func main() {
listen := flag.String("listen", envOr("AGGREGATOR_LISTEN", ":9091"), "gRPC listen address (env: AGGREGATOR_LISTEN)")
collectors := flag.String("collectors", envOr("AGGREGATOR_COLLECTORS", ""), "comma-separated collector host:port addresses (env: AGGREGATOR_COLLECTORS)")
source := flag.String("source", envOr("AGGREGATOR_SOURCE", hostname()), "name for this aggregator in responses (env: AGGREGATOR_SOURCE, default: hostname)")
flag.Parse()
if *collectors == "" {
log.Fatal("aggregator: --collectors / AGGREGATOR_COLLECTORS is required")
}
ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
defer stop()
var collectorAddrs []string
for _, addr := range strings.Split(*collectors, ",") {
addr = strings.TrimSpace(addr)
if addr != "" {
collectorAddrs = append(collectorAddrs, addr)
}
}
merger := NewMerger()
cache := NewCache(merger, *source)
registry := NewTargetRegistry(collectorAddrs)
go cache.Run(ctx)
for _, addr := range collectorAddrs {
sub := NewCollectorSub(addr, merger, registry)
go sub.Run(ctx)
log.Printf("aggregator: subscribing to collector %s", addr)
}
lis, err := net.Listen("tcp", *listen)
if err != nil {
log.Fatalf("aggregator: failed to listen on %s: %v", *listen, err)
}
grpcServer := grpc.NewServer()
pb.RegisterLogtailServiceServer(grpcServer, NewServer(cache, *source, registry))
go func() {
log.Printf("aggregator: gRPC listening on %s (source=%s)", *listen, *source)
if err := grpcServer.Serve(lis); err != nil {
log.Printf("aggregator: gRPC server stopped: %v", err)
}
}()
<-ctx.Done()
log.Printf("aggregator: shutting down")
grpcServer.GracefulStop()
}
func hostname() string {
h, err := os.Hostname()
if err != nil {
return "unknown"
}
return h
}
func envOr(key, def string) string {
if v := os.Getenv(key); v != "" {
return v
}
return def
}