112 lines
3.1 KiB
Go
112 lines
3.1 KiB
Go
package main
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import (
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"context"
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"flag"
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"fmt"
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"log/slog"
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"net"
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"os"
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"os/signal"
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"syscall"
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"google.golang.org/grpc"
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"git.ipng.ch/ipng/vpp-maglev/internal/checker"
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"git.ipng.ch/ipng/vpp-maglev/internal/config"
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"git.ipng.ch/ipng/vpp-maglev/internal/grpcapi"
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)
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func main() {
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if err := run(); err != nil {
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slog.Error("startup-fatal", "err", err)
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os.Exit(1)
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}
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}
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func run() error {
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// ---- flags / env --------------------------------------------------------
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configPath := stringFlag("config", "/etc/maglev/frontend.yaml", "MAGLEV_CONFIG", "path to frontend.yaml")
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grpcAddr := stringFlag("grpc-addr", ":9090", "MAGLEV_GRPC_ADDR", "gRPC listen address")
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logLevel := stringFlag("log-level", "info", "MAGLEV_LOG_LEVEL", "log level (debug|info|warn|error)")
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flag.Parse()
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// ---- logging ------------------------------------------------------------
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var level slog.Level
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if err := level.UnmarshalText([]byte(*logLevel)); err != nil {
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return fmt.Errorf("invalid log level %q: %w", *logLevel, err)
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}
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slog.SetDefault(slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level})))
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// ---- config -------------------------------------------------------------
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cfg, err := config.Load(*configPath)
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if err != nil {
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return fmt.Errorf("load config: %w", err)
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}
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slog.Info("config-loaded", "path", *configPath, "vips", len(cfg.VIPs))
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// ---- checker ------------------------------------------------------------
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chkr := checker.New(cfg)
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ctx, rootCancel := context.WithCancel(context.Background())
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defer rootCancel()
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go func() {
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if err := chkr.Run(ctx); err != nil {
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slog.Error("checker-exited", "err", err)
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}
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}()
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// ---- gRPC server --------------------------------------------------------
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lis, err := net.Listen("tcp", *grpcAddr)
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if err != nil {
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return fmt.Errorf("listen %s: %w", *grpcAddr, err)
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}
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srv := grpc.NewServer()
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grpcapi.RegisterHealthCheckerServer(srv, grpcapi.NewServer(chkr))
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slog.Info("grpc-listening", "addr", *grpcAddr)
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go func() {
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if err := srv.Serve(lis); err != nil {
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slog.Error("grpc-serve-error", "err", err)
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}
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}()
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// ---- signal handling ----------------------------------------------------
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sigCh := make(chan os.Signal, 1)
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signal.Notify(sigCh, syscall.SIGHUP, syscall.SIGTERM, syscall.SIGINT)
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for sig := range sigCh {
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switch sig {
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case syscall.SIGHUP:
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slog.Info("config-reload-start")
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newCfg, err := config.Load(*configPath)
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if err != nil {
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slog.Error("config-reload-error", "err", err)
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continue
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}
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if err := chkr.Reload(ctx, newCfg); err != nil {
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slog.Error("checker-reload-error", "err", err)
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continue
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}
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slog.Info("config-reload-done", "vips", len(newCfg.VIPs))
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case syscall.SIGTERM, syscall.SIGINT:
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slog.Info("shutdown", "signal", sig)
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rootCancel()
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srv.GracefulStop()
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return nil
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}
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}
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return nil
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}
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// stringFlag declares a flag that falls back to an environment variable.
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func stringFlag(name, defaultVal, envKey, usage string) *string {
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val := defaultVal
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if v := os.Getenv(envKey); v != "" {
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val = v
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}
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return flag.String(name, val, fmt.Sprintf("%s (env: %s)", usage, envKey))
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}
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