talos/internal/pkg/dns/runnner.go
Dmitriy Matrenichev dab30a8b9f
fix: ensure no goroutines escape in dns controller
- Remove all reliance on finalizers.
- Add `Close` method to CoreDNS `Proxy` struct.
- Wait for `Runner.Serve` to complete.

Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>
2025-03-07 22:08:46 +03:00

96 lines
2.2 KiB
Go

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
package dns
import (
"context"
"errors"
"io"
"net"
"time"
"github.com/miekg/dns"
"go.uber.org/zap"
"golang.org/x/sync/errgroup"
)
// RunnerOptions is a [Runner] options.
type RunnerOptions struct {
Listener net.Listener
PacketConn net.PacketConn
Handler dns.Handler
ReadTimeout time.Duration
WriteTimeout time.Duration
IdleTimeout func() time.Duration
MaxTCPQueries int
}
// NewRunner creates a new [Runner].
func NewRunner(opts RunnerOptions, l *zap.Logger) *Runner {
return &Runner{
srv: &dns.Server{
Listener: opts.Listener,
PacketConn: opts.PacketConn,
Handler: opts.Handler,
UDPSize: dns.DefaultMsgSize, // 4096 since default is [dns.MinMsgSize] = 512 bytes, which is too small.
ReadTimeout: opts.ReadTimeout,
WriteTimeout: opts.WriteTimeout,
IdleTimeout: opts.IdleTimeout,
MaxTCPQueries: opts.MaxTCPQueries,
},
logger: l,
}
}
// Runner is a DNS server runner.
type Runner struct {
srv *dns.Server
logger *zap.Logger
}
// Serve starts the DNS server. Implements [suture.Service] interface.
func (r *Runner) Serve(ctx context.Context) error {
eg, ctx := errgroup.WithContext(ctx)
eg.Go(r.srv.ActivateAndServe)
<-ctx.Done()
r.close()
return eg.Wait()
}
func (r *Runner) close() {
l := r.logger
if r.srv.Listener != nil {
l = l.With(zap.String("net", "tcp"), zap.String("local_addr", r.srv.Listener.Addr().String()))
} else if r.srv.PacketConn != nil {
l = l.With(zap.String("net", "udp"), zap.String("local_addr", r.srv.PacketConn.LocalAddr().String()))
}
closer := io.Closer(r.srv.Listener)
if closer == nil {
closer = r.srv.PacketConn
}
if closer != nil {
if err := closer.Close(); err != nil {
l.Error("error closing dns server listener", zap.Error(err))
} else {
l.Debug("dns server listener closed")
}
}
sCtx, sCancel := context.WithTimeout(context.Background(), 5*time.Second)
defer sCancel()
err := r.srv.ShutdownContext(sCtx)
if err != nil && !errors.Is(err, net.ErrClosed) {
l.Error("error shutting down dns server", zap.Error(err))
}
}