github.com/containerd/containerd@v22.0.0-20200918172823-438c87b8e050+incompatible/runtime/v2/shim/util_windows.go (about)

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  package shim
    18  
    19  import (
    20  	"context"
    21  	"net"
    22  	"os"
    23  	"syscall"
    24  	"time"
    25  
    26  	winio "github.com/Microsoft/go-winio"
    27  	"github.com/pkg/errors"
    28  )
    29  
    30  const shimBinaryFormat = "containerd-shim-%s-%s.exe"
    31  
    32  func getSysProcAttr() *syscall.SysProcAttr {
    33  	return nil
    34  }
    35  
    36  // AnonReconnectDialer returns a dialer for an existing npipe on containerd reconnection
    37  func AnonReconnectDialer(address string, timeout time.Duration) (net.Conn, error) {
    38  	ctx, cancel := context.WithTimeout(context.Background(), timeout)
    39  	defer cancel()
    40  
    41  	c, err := winio.DialPipeContext(ctx, address)
    42  	if os.IsNotExist(err) {
    43  		return nil, errors.Wrap(os.ErrNotExist, "npipe not found on reconnect")
    44  	} else if err == context.DeadlineExceeded {
    45  		return nil, errors.Wrapf(err, "timed out waiting for npipe %s", address)
    46  	} else if err != nil {
    47  		return nil, err
    48  	}
    49  	return c, nil
    50  }
    51  
    52  // AnonDialer returns a dialer for a npipe
    53  func AnonDialer(address string, timeout time.Duration) (net.Conn, error) {
    54  	ctx, cancel := context.WithTimeout(context.Background(), timeout)
    55  	defer cancel()
    56  
    57  	// If there is nobody serving the pipe we limit the timeout for this case to
    58  	// 5 seconds because any shim that would serve this endpoint should serve it
    59  	// within 5 seconds.
    60  	serveTimer := time.NewTimer(5 * time.Second)
    61  	defer serveTimer.Stop()
    62  	for {
    63  		c, err := winio.DialPipeContext(ctx, address)
    64  		if err != nil {
    65  			if os.IsNotExist(err) {
    66  				select {
    67  				case <-serveTimer.C:
    68  					return nil, errors.Wrap(os.ErrNotExist, "pipe not found before timeout")
    69  				default:
    70  					// Wait 10ms for the shim to serve and try again.
    71  					time.Sleep(10 * time.Millisecond)
    72  					continue
    73  				}
    74  			} else if err == context.DeadlineExceeded {
    75  				return nil, errors.Wrapf(err, "timed out waiting for npipe %s", address)
    76  			}
    77  			return nil, err
    78  		}
    79  		return c, nil
    80  	}
    81  }