github.com/docker/docker@v299999999.0.0-20200612211812-aaf470eca7b5+incompatible/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/docker/daemon/config"
    12  	"github.com/docker/docker/pkg/idtools"
    13  	"github.com/docker/docker/pkg/stringid"
    14  	"github.com/docker/libnetwork"
    15  	"github.com/moby/buildkit/executor"
    16  	"github.com/moby/buildkit/executor/oci"
    17  	"github.com/moby/buildkit/executor/runcexecutor"
    18  	"github.com/moby/buildkit/identity"
    19  	"github.com/moby/buildkit/solver/pb"
    20  	"github.com/moby/buildkit/util/network"
    21  	specs "github.com/opencontainers/runtime-spec/specs-go"
    22  	"github.com/sirupsen/logrus"
    23  )
    24  
    25  const networkName = "bridge"
    26  
    27  func newExecutor(root, cgroupParent string, net libnetwork.NetworkController, dnsConfig *oci.DNSConfig, rootless bool, idmap *idtools.IdentityMapping) (executor.Executor, error) {
    28  	networkProviders := map[pb.NetMode]network.Provider{
    29  		pb.NetMode_UNSET: &bridgeProvider{NetworkController: net, Root: filepath.Join(root, "net")},
    30  		pb.NetMode_HOST:  network.NewHostProvider(),
    31  		pb.NetMode_NONE:  network.NewNoneProvider(),
    32  	}
    33  	return runcexecutor.New(runcexecutor.Opt{
    34  		Root:                filepath.Join(root, "executor"),
    35  		CommandCandidates:   []string{"runc"},
    36  		DefaultCgroupParent: cgroupParent,
    37  		Rootless:            rootless,
    38  		NoPivot:             os.Getenv("DOCKER_RAMDISK") != "",
    39  		IdentityMapping:     idmap,
    40  		DNS:                 dnsConfig,
    41  	}, networkProviders)
    42  }
    43  
    44  type bridgeProvider struct {
    45  	libnetwork.NetworkController
    46  	Root string
    47  }
    48  
    49  func (p *bridgeProvider) New() (network.Namespace, error) {
    50  	n, err := p.NetworkByName(networkName)
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  
    55  	iface := &lnInterface{ready: make(chan struct{}), provider: p}
    56  	iface.Once.Do(func() {
    57  		go iface.init(p.NetworkController, n)
    58  	})
    59  
    60  	return iface, nil
    61  }
    62  
    63  type lnInterface struct {
    64  	ep  libnetwork.Endpoint
    65  	sbx libnetwork.Sandbox
    66  	sync.Once
    67  	err      error
    68  	ready    chan struct{}
    69  	provider *bridgeProvider
    70  }
    71  
    72  func (iface *lnInterface) init(c libnetwork.NetworkController, n libnetwork.Network) {
    73  	defer close(iface.ready)
    74  	id := identity.NewID()
    75  
    76  	ep, err := n.CreateEndpoint(id, libnetwork.CreateOptionDisableResolution())
    77  	if err != nil {
    78  		iface.err = err
    79  		return
    80  	}
    81  
    82  	sbx, err := c.NewSandbox(id, libnetwork.OptionUseExternalKey(), libnetwork.OptionHostsPath(filepath.Join(iface.provider.Root, id, "hosts")),
    83  		libnetwork.OptionResolvConfPath(filepath.Join(iface.provider.Root, id, "resolv.conf")))
    84  	if err != nil {
    85  		iface.err = err
    86  		return
    87  	}
    88  
    89  	if err := ep.Join(sbx); err != nil {
    90  		iface.err = err
    91  		return
    92  	}
    93  
    94  	iface.sbx = sbx
    95  	iface.ep = ep
    96  }
    97  
    98  func (iface *lnInterface) Set(s *specs.Spec) {
    99  	<-iface.ready
   100  	if iface.err != nil {
   101  		logrus.WithError(iface.err).Error("failed to set networking spec")
   102  		return
   103  	}
   104  	shortNetCtlrID := stringid.TruncateID(iface.provider.NetworkController.ID())
   105  	// attach netns to bridge within the container namespace, using reexec in a prestart hook
   106  	s.Hooks = &specs.Hooks{
   107  		Prestart: []specs.Hook{{
   108  			Path: filepath.Join("/proc", strconv.Itoa(os.Getpid()), "exe"),
   109  			Args: []string{"libnetwork-setkey", "-exec-root=" + iface.provider.Config().Daemon.ExecRoot, iface.sbx.ContainerID(), shortNetCtlrID},
   110  		}},
   111  	}
   112  }
   113  
   114  func (iface *lnInterface) Close() error {
   115  	<-iface.ready
   116  	if iface.sbx != nil {
   117  		go func() {
   118  			if err := iface.sbx.Delete(); err != nil {
   119  				logrus.Errorf("failed to delete builder network sandbox: %v", err)
   120  			}
   121  		}()
   122  	}
   123  	return iface.err
   124  }
   125  
   126  func getDNSConfig(cfg config.DNSConfig) *oci.DNSConfig {
   127  	if cfg.DNS != nil || cfg.DNSSearch != nil || cfg.DNSOptions != nil {
   128  		return &oci.DNSConfig{
   129  			Nameservers:   cfg.DNS,
   130  			SearchDomains: cfg.DNSSearch,
   131  			Options:       cfg.DNSOptions,
   132  		}
   133  	}
   134  	return nil
   135  }