create pkg/reuseport (#3455)

* create pkg/reuseport

Move the core server listening functions to a new package so plugins can
use them.

Also make *all* servers use the functions here; as only the udp/tcp
listeners where using SO_REUSEPORT (if available). This is the only
actual change in this PR; in it's core it's just a move of 2 files.

This can also be used to cleanup the dance we're doing now for
re-acquiring the sockets in e.g. the metrics plugins and the ready
plugin.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Also push a small doc update

Signed-off-by: Miek Gieben <miek@miek.nl>
This commit is contained in:
Miek Gieben
2019-11-17 02:02:46 +00:00
committed by Yong Tang
parent 4831e7f947
commit e14e053d3d
9 changed files with 64 additions and 49 deletions

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@@ -1,33 +0,0 @@
// +build go1.11
// +build aix darwin dragonfly freebsd linux netbsd openbsd
package dnsserver
import (
"context"
"net"
"syscall"
"github.com/coredns/coredns/plugin/pkg/log"
"golang.org/x/sys/unix"
)
func reuseportControl(network, address string, c syscall.RawConn) error {
c.Control(func(fd uintptr) {
if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
log.Warningf("Failed to set SO_REUSEPORT on socket: %s", err)
}
})
return nil
}
func listen(network, addr string) (net.Listener, error) {
lc := net.ListenConfig{Control: reuseportControl}
return lc.Listen(context.Background(), network, addr)
}
func listenPacket(network, addr string) (net.PacketConn, error) {
lc := net.ListenConfig{Control: reuseportControl}
return lc.ListenPacket(context.Background(), network, addr)
}

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@@ -1,11 +0,0 @@
// +build !go1.11 !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd
package dnsserver
import "net"
func listen(network, addr string) (net.Listener, error) { return net.Listen(network, addr) }
func listenPacket(network, addr string) (net.PacketConn, error) {
return net.ListenPacket(network, addr)
}

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@@ -15,6 +15,7 @@ import (
"github.com/coredns/coredns/plugin/pkg/edns"
"github.com/coredns/coredns/plugin/pkg/log"
"github.com/coredns/coredns/plugin/pkg/rcode"
"github.com/coredns/coredns/plugin/pkg/reuseport"
"github.com/coredns/coredns/plugin/pkg/trace"
"github.com/coredns/coredns/plugin/pkg/transport"
"github.com/coredns/coredns/request"
@@ -126,7 +127,7 @@ func (s *Server) ServePacket(p net.PacketConn) error {
// Listen implements caddy.TCPServer interface.
func (s *Server) Listen() (net.Listener, error) {
l, err := listen("tcp", s.Addr[len(transport.DNS+"://"):])
l, err := reuseport.Listen("tcp", s.Addr[len(transport.DNS+"://"):])
if err != nil {
return nil, err
}
@@ -140,7 +141,7 @@ func (s *Server) WrapListener(ln net.Listener) net.Listener {
// ListenPacket implements caddy.UDPServer interface.
func (s *Server) ListenPacket() (net.PacketConn, error) {
p, err := listenPacket("udp", s.Addr[len(transport.DNS+"://"):])
p, err := reuseport.ListenPacket("udp", s.Addr[len(transport.DNS+"://"):])
if err != nil {
return nil, err
}

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@@ -8,6 +8,7 @@ import (
"net"
"github.com/coredns/coredns/pb"
"github.com/coredns/coredns/plugin/pkg/reuseport"
"github.com/coredns/coredns/plugin/pkg/transport"
"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
@@ -72,7 +73,7 @@ func (s *ServergRPC) ServePacket(p net.PacketConn) error { return nil }
// Listen implements caddy.TCPServer interface.
func (s *ServergRPC) Listen() (net.Listener, error) {
l, err := net.Listen("tcp", s.Addr[len(transport.GRPC+"://"):])
l, err := reuseport.Listen("tcp", s.Addr[len(transport.GRPC+"://"):])
if err != nil {
return nil, err
}

View File

@@ -12,6 +12,7 @@ import (
"github.com/coredns/coredns/plugin/pkg/dnsutil"
"github.com/coredns/coredns/plugin/pkg/doh"
"github.com/coredns/coredns/plugin/pkg/response"
"github.com/coredns/coredns/plugin/pkg/reuseport"
"github.com/coredns/coredns/plugin/pkg/transport"
)
@@ -61,7 +62,7 @@ func (s *ServerHTTPS) ServePacket(p net.PacketConn) error { return nil }
// Listen implements caddy.TCPServer interface.
func (s *ServerHTTPS) Listen() (net.Listener, error) {
l, err := net.Listen("tcp", s.Addr[len(transport.HTTPS+"://"):])
l, err := reuseport.Listen("tcp", s.Addr[len(transport.HTTPS+"://"):])
if err != nil {
return nil, err
}

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@@ -6,6 +6,7 @@ import (
"fmt"
"net"
"github.com/coredns/coredns/plugin/pkg/reuseport"
"github.com/coredns/coredns/plugin/pkg/transport"
"github.com/miekg/dns"
@@ -57,7 +58,7 @@ func (s *ServerTLS) ServePacket(p net.PacketConn) error { return nil }
// Listen implements caddy.TCPServer interface.
func (s *ServerTLS) Listen() (net.Listener, error) {
l, err := net.Listen("tcp", s.Addr[len(transport.TLS+"://"):])
l, err := reuseport.Listen("tcp", s.Addr[len(transport.TLS+"://"):])
if err != nil {
return nil, err
}

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@@ -64,6 +64,11 @@ a *Metrics* section detailing the metrics.
If the plugin supports signalling readiness it should have a *Ready* section detailing how it
works, and implement the `ready.Readiness` interface.
## Opening Sockets
See the plugin/pkg/reuseport for `Listen` and `ListenPacket` functions. Using these functions makes
you plugin handle reload events better.
## Documentation
Each plugin should have a README.md explaining what the plugin does and how it is configured. The

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@@ -0,0 +1,37 @@
// +build go1.11
// +build aix darwin dragonfly freebsd linux netbsd openbsd
package reuseport
import (
"context"
"net"
"syscall"
"github.com/coredns/coredns/plugin/pkg/log"
"golang.org/x/sys/unix"
)
func control(network, address string, c syscall.RawConn) error {
c.Control(func(fd uintptr) {
if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
log.Warningf("Failed to set SO_REUSEPORT on socket: %s", err)
}
})
return nil
}
// Listen announces on the local network address. See net.Listen for more information.
// If SO_REUSEPORT is available it will be set on the socket.
func Listen(network, addr string) (net.Listener, error) {
lc := net.ListenConfig{Control: control}
return lc.Listen(context.Background(), network, addr)
}
// ListenPacket announces on the local network address. See net.ListenPacket for more information.
// If SO_REUSEPORT is available it will be set on the socket.
func ListenPacket(network, addr string) (net.PacketConn, error) {
lc := net.ListenConfig{Control: control}
return lc.ListenPacket(context.Background(), network, addr)
}

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@@ -0,0 +1,13 @@
// +build !go1.11 !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd
package reuseport
import "net"
// Listen is a wrapper around net.Listen.
func Listen(network, addr string) (net.Listener, error) { return net.Listen(network, addr) }
// ListenPacket is a wrapper around net.ListenPacket.
func ListenPacket(network, addr string) (net.PacketConn, error) {
return net.ListenPacket(network, addr)
}