github.com/zhouyu0/docker-note@v0.0.0-20190722021225-b8d3825084db/builder/builder-next/executor_unix.go (about)

     1  // +build !windows
     2  
     3  package buildkit
     4  
     5  import (
     6  	"os"
     7  	"path/filepath"
     8  	"strconv"
     9  	"sync"
    10  
    11  	"github.com/docker/libnetwork"
    12  	"github.com/moby/buildkit/executor"
    13  	"github.com/moby/buildkit/executor/runcexecutor"
    14  	"github.com/moby/buildkit/identity"
    15  	"github.com/moby/buildkit/solver/pb"
    16  	"github.com/moby/buildkit/util/network"
    17  	specs "github.com/opencontainers/runtime-spec/specs-go"
    18  	"github.com/sirupsen/logrus"
    19  )
    20  
    21  const networkName = "bridge"
    22  
    23  func newExecutor(root, cgroupParent string, net libnetwork.NetworkController) (executor.Executor, error) {
    24  	networkProviders := map[pb.NetMode]network.Provider{
    25  		pb.NetMode_UNSET: &bridgeProvider{NetworkController: net},
    26  		pb.NetMode_HOST:  network.NewHostProvider(),
    27  		pb.NetMode_NONE:  network.NewNoneProvider(),
    28  	}
    29  	return runcexecutor.New(runcexecutor.Opt{
    30  		Root:                filepath.Join(root, "executor"),
    31  		CommandCandidates:   []string{"runc"},
    32  		DefaultCgroupParent: cgroupParent,
    33  	}, networkProviders)
    34  }
    35  
    36  type bridgeProvider struct {
    37  	libnetwork.NetworkController
    38  }
    39  
    40  func (p *bridgeProvider) New() (network.Namespace, error) {
    41  	n, err := p.NetworkByName(networkName)
    42  	if err != nil {
    43  		return nil, err
    44  	}
    45  
    46  	iface := &lnInterface{ready: make(chan struct{}), provider: p}
    47  	iface.Once.Do(func() {
    48  		go iface.init(p.NetworkController, n)
    49  	})
    50  
    51  	return iface, nil
    52  }
    53  
    54  type lnInterface struct {
    55  	ep  libnetwork.Endpoint
    56  	sbx libnetwork.Sandbox
    57  	sync.Once
    58  	err      error
    59  	ready    chan struct{}
    60  	provider *bridgeProvider
    61  }
    62  
    63  func (iface *lnInterface) init(c libnetwork.NetworkController, n libnetwork.Network) {
    64  	defer close(iface.ready)
    65  	id := identity.NewID()
    66  
    67  	ep, err := n.CreateEndpoint(id, libnetwork.CreateOptionDisableResolution())
    68  	if err != nil {
    69  		iface.err = err
    70  		return
    71  	}
    72  
    73  	sbx, err := c.NewSandbox(id, libnetwork.OptionUseExternalKey())
    74  	if err != nil {
    75  		iface.err = err
    76  		return
    77  	}
    78  
    79  	if err := ep.Join(sbx); err != nil {
    80  		iface.err = err
    81  		return
    82  	}
    83  
    84  	iface.sbx = sbx
    85  	iface.ep = ep
    86  }
    87  
    88  func (iface *lnInterface) Set(s *specs.Spec) {
    89  	<-iface.ready
    90  	if iface.err != nil {
    91  		return
    92  	}
    93  	// attach netns to bridge within the container namespace, using reexec in a prestart hook
    94  	s.Hooks = &specs.Hooks{
    95  		Prestart: []specs.Hook{{
    96  			Path: filepath.Join("/proc", strconv.Itoa(os.Getpid()), "exe"),
    97  			Args: []string{"libnetwork-setkey", iface.sbx.ContainerID(), iface.provider.NetworkController.ID()},
    98  		}},
    99  	}
   100  }
   101  
   102  func (iface *lnInterface) Close() error {
   103  	<-iface.ready
   104  	go func() {
   105  		if err := iface.sbx.Delete(); err != nil {
   106  			logrus.Errorf("failed to delete builder network sandbox: %v", err)
   107  		}
   108  	}()
   109  	return iface.err
   110  }