Fix lint in Unix environments

Signed-off-by: Derek McGowan <derek@mcg.dev>
2020-10-05 09:11:21 -07:00
parent d620c30d7e
commit 07c98d0bf1
50 changed files with 540 additions and 83 deletions
--- a/pkg/server/sandbox_portforward_linux.go
+++ b/pkg/server/sandbox_portforward_linux.go
@@ -0,0 +1,126 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package server
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"time"
+
+	"github.com/containerd/containerd/log"
+	"github.com/containernetworking/plugins/pkg/ns"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+
+	runtime "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
+)
+
+// portForward uses netns to enter the sandbox namespace, and forwards a stream inside the
+// the namespace to a specific port. It keeps forwarding until it exits or client disconnect.
+func (c *criService) portForward(ctx context.Context, id string, port int32, stream io.ReadWriteCloser) error {
+	s, err := c.sandboxStore.Get(id)
+	if err != nil {
+		return errors.Wrapf(err, "failed to find sandbox %q in store", id)
+	}
+
+	var netNSDo func(func(ns.NetNS) error) error
+	// netNSPath is the network namespace path for logging.
+	var netNSPath string
+	securityContext := s.Config.GetLinux().GetSecurityContext()
+	hostNet := securityContext.GetNamespaceOptions().GetNetwork() == runtime.NamespaceMode_NODE
+	if !hostNet {
+		if closed, err := s.NetNS.Closed(); err != nil {
+			return errors.Wrapf(err, "failed to check netwok namespace closed for sandbox %q", id)
+		} else if closed {
+			return errors.Errorf("network namespace for sandbox %q is closed", id)
+		}
+		netNSDo = s.NetNS.Do
+		netNSPath = s.NetNS.GetPath()
+	} else {
+		// Run the function directly for host network.
+		netNSDo = func(do func(_ ns.NetNS) error) error {
+			return do(nil)
+		}
+		netNSPath = "host"
+	}
+
+	log.G(ctx).Infof("Executing port forwarding in network namespace %q", netNSPath)
+	err = netNSDo(func(_ ns.NetNS) error {
+		defer stream.Close()
+		// TODO: hardcoded to tcp4 because localhost resolves to ::1 by default if the system has IPv6 enabled.
+		// Theoretically happy eyeballs will try IPv6 first and fallback to IPv4
+		// but resolving localhost doesn't seem to return and IPv4 address, thus failing the connection.
+		conn, err := net.Dial("tcp4", fmt.Sprintf("localhost:%d", port))
+		if err != nil {
+			return errors.Wrapf(err, "failed to dial %d", port)
+		}
+		defer conn.Close()
+
+		errCh := make(chan error, 2)
+		// Copy from the the namespace port connection to the client stream
+		go func() {
+			log.G(ctx).Debugf("PortForward copying data from namespace %q port %d to the client stream", id, port)
+			_, err := io.Copy(stream, conn)
+			errCh <- err
+		}()
+
+		// Copy from the client stream to the namespace port connection
+		go func() {
+			log.G(ctx).Debugf("PortForward copying data from client stream to namespace %q port %d", id, port)
+			_, err := io.Copy(conn, stream)
+			errCh <- err
+		}()
+
+		// Wait until the first error is returned by one of the connections
+		// we use errFwd to store the result of the port forwarding operation
+		// if the context is cancelled close everything and return
+		var errFwd error
+		select {
+		case errFwd = <-errCh:
+			log.G(ctx).Debugf("PortForward stop forwarding in one direction in network namespace %q port %d: %v", id, port, errFwd)
+		case <-ctx.Done():
+			log.G(ctx).Debugf("PortForward cancelled in network namespace %q port %d: %v", id, port, ctx.Err())
+			return ctx.Err()
+		}
+		// give a chance to terminate gracefully or timeout
+		// after 1s
+		// https://linux.die.net/man/1/socat
+		const timeout = time.Second
+		select {
+		case e := <-errCh:
+			if errFwd == nil {
+				errFwd = e
+			}
+			log.G(ctx).Debugf("PortForward stopped forwarding in both directions in network namespace %q port %d: %v", id, port, e)
+		case <-time.After(timeout):
+			log.G(ctx).Debugf("PortForward timed out waiting to close the connection in network namespace %q port %d", id, port)
+		case <-ctx.Done():
+			log.G(ctx).Debugf("PortForward cancelled in network namespace %q port %d: %v", id, port, ctx.Err())
+			errFwd = ctx.Err()
+		}
+
+		return errFwd
+	})
+
+	if err != nil {
+		return errors.Wrapf(err, "failed to execute portforward in network namespace %q", netNSPath)
+	}
+	log.G(ctx).Infof("Finish port forwarding for %q port %d", id, port)
+
+	return nil
+}