package libnetwork import ( "bytes" "encoding/json" "fmt" "io/ioutil" "os" "path" "path/filepath" "sync" log "github.com/Sirupsen/logrus" "github.com/docker/docker/pkg/ioutils" "github.com/docker/libnetwork/datastore" "github.com/docker/libnetwork/etchosts" "github.com/docker/libnetwork/netlabel" "github.com/docker/libnetwork/resolvconf" "github.com/docker/libnetwork/sandbox" "github.com/docker/libnetwork/types" ) // Endpoint represents a logical connection between a network and a sandbox. type Endpoint interface { // A system generated id for this endpoint. ID() string // Name returns the name of this endpoint. Name() string // Network returns the name of the network to which this endpoint is attached. Network() string // Join creates a new sandbox for the given container ID and populates the // network resources allocated for the endpoint and joins the sandbox to // the endpoint. Join(containerID string, options ...EndpointOption) error // Leave removes the sandbox associated with container ID and detaches // the network resources populated in the sandbox Leave(containerID string, options ...EndpointOption) error // Return certain operational data belonging to this endpoint Info() EndpointInfo // DriverInfo returns a collection of driver operational data related to this endpoint retrieved from the driver DriverInfo() (map[string]interface{}, error) // ContainerInfo returns the info available at the endpoint about the attached container ContainerInfo() ContainerInfo // Delete and detaches this endpoint from the network. Delete() error // Retrieve the interfaces' statistics from the sandbox Statistics() (map[string]*sandbox.InterfaceStatistics, error) } // EndpointOption is a option setter function type used to pass varios options to Network // and Endpoint interfaces methods. The various setter functions of type EndpointOption are // provided by libnetwork, they look like Option[...](...) type EndpointOption func(ep *endpoint) // ContainerData is a set of data returned when a container joins an endpoint. type ContainerData struct { SandboxKey string } // These are the container configs used to customize container /etc/hosts file. type hostsPathConfig struct { hostName string domainName string hostsPath string extraHosts []extraHost parentUpdates []parentUpdate } // These are the container configs used to customize container /etc/resolv.conf file. type resolvConfPathConfig struct { resolvConfPath string dnsList []string dnsSearchList []string } type containerConfig struct { hostsPathConfig resolvConfPathConfig generic map[string]interface{} useDefaultSandBox bool prio int // higher the value, more the priority } type extraHost struct { name string IP string } type parentUpdate struct { eid string name string ip string } type containerInfo struct { id string config containerConfig data ContainerData sync.Mutex } func (ci *containerInfo) ID() string { return ci.id } func (ci *containerInfo) Labels() map[string]interface{} { return ci.config.generic } type endpoint struct { name string id types.UUID network *network iFaces []*endpointInterface joinInfo *endpointJoinInfo container *containerInfo exposedPorts []types.TransportPort generic map[string]interface{} joinLeaveDone chan struct{} dbIndex uint64 dbExists bool sync.Mutex } func (ci *containerInfo) MarshalJSON() ([]byte, error) { ci.Lock() defer ci.Unlock() // We are just interested in the container ID. This can be expanded to include all of containerInfo if there is a need return json.Marshal(ci.id) } func (ci *containerInfo) UnmarshalJSON(b []byte) (err error) { ci.Lock() defer ci.Unlock() var id string if err := json.Unmarshal(b, &id); err != nil { return err } ci.id = id return nil } func (ep *endpoint) MarshalJSON() ([]byte, error) { ep.Lock() defer ep.Unlock() epMap := make(map[string]interface{}) epMap["name"] = ep.name epMap["id"] = string(ep.id) epMap["ep_iface"] = ep.iFaces epMap["exposed_ports"] = ep.exposedPorts epMap["generic"] = ep.generic if ep.container != nil { epMap["container"] = ep.container } return json.Marshal(epMap) } func (ep *endpoint) UnmarshalJSON(b []byte) (err error) { ep.Lock() defer ep.Unlock() var epMap map[string]interface{} if err := json.Unmarshal(b, &epMap); err != nil { return err } ep.name = epMap["name"].(string) ep.id = types.UUID(epMap["id"].(string)) ib, _ := json.Marshal(epMap["ep_iface"]) var ifaces []endpointInterface json.Unmarshal(ib, &ifaces) ep.iFaces = make([]*endpointInterface, 0) for _, iface := range ifaces { ep.iFaces = append(ep.iFaces, &iface) } tb, _ := json.Marshal(epMap["exposed_ports"]) var tPorts []types.TransportPort json.Unmarshal(tb, &tPorts) ep.exposedPorts = tPorts epc, ok := epMap["container"] if ok { cb, _ := json.Marshal(epc) var cInfo containerInfo json.Unmarshal(cb, &cInfo) ep.container = &cInfo } if epMap["generic"] != nil { ep.generic = epMap["generic"].(map[string]interface{}) } return nil } const defaultPrefix = "/var/lib/docker/network/files" func (ep *endpoint) ID() string { ep.Lock() defer ep.Unlock() return string(ep.id) } func (ep *endpoint) Name() string { ep.Lock() defer ep.Unlock() return ep.name } func (ep *endpoint) Network() string { ep.Lock() defer ep.Unlock() return ep.network.name } // endpoint Key structure : endpoint/network-id/endpoint-id func (ep *endpoint) Key() []string { ep.Lock() n := ep.network defer ep.Unlock() return []string{datastore.EndpointKeyPrefix, string(n.id), string(ep.id)} } func (ep *endpoint) KeyPrefix() []string { ep.Lock() n := ep.network defer ep.Unlock() return []string{datastore.EndpointKeyPrefix, string(n.id)} } func (ep *endpoint) networkIDFromKey(key []string) (types.UUID, error) { // endpoint Key structure : endpoint/network-id/endpoint-id // it's an invalid key if the key doesn't have all the 3 key elements above if key == nil || len(key) < 3 || key[0] != datastore.EndpointKeyPrefix { return types.UUID(""), fmt.Errorf("invalid endpoint key : %v", key) } // network-id is placed at index=1. pls refer to endpoint.Key() method return types.UUID(key[1]), nil } func (ep *endpoint) Value() []byte { b, err := json.Marshal(ep) if err != nil { return nil } return b } func (ep *endpoint) SetValue(value []byte) error { return json.Unmarshal(value, ep) } func (ep *endpoint) Index() uint64 { ep.Lock() defer ep.Unlock() return ep.dbIndex } func (ep *endpoint) SetIndex(index uint64) { ep.Lock() defer ep.Unlock() ep.dbIndex = index ep.dbExists = true } func (ep *endpoint) Exists() bool { ep.Lock() defer ep.Unlock() return ep.dbExists } func (ep *endpoint) processOptions(options ...EndpointOption) { ep.Lock() defer ep.Unlock() for _, opt := range options { if opt != nil { opt(ep) } } } func createBasePath(dir string) error { return os.MkdirAll(dir, 0644) } func createFile(path string) error { var f *os.File dir, _ := filepath.Split(path) err := createBasePath(dir) if err != nil { return err } f, err = os.Create(path) if err == nil { f.Close() } return err } // joinLeaveStart waits to ensure there are no joins or leaves in progress and // marks this join/leave in progress without race func (ep *endpoint) joinLeaveStart() { ep.Lock() defer ep.Unlock() for ep.joinLeaveDone != nil { joinLeaveDone := ep.joinLeaveDone ep.Unlock() select { case <-joinLeaveDone: } ep.Lock() } ep.joinLeaveDone = make(chan struct{}) } // joinLeaveEnd marks the end of this join/leave operation and // signals the same without race to other join and leave waiters func (ep *endpoint) joinLeaveEnd() { ep.Lock() defer ep.Unlock() if ep.joinLeaveDone != nil { close(ep.joinLeaveDone) ep.joinLeaveDone = nil } } func (ep *endpoint) Join(containerID string, options ...EndpointOption) error { var err error if containerID == "" { return InvalidContainerIDError(containerID) } ep.joinLeaveStart() defer func() { ep.joinLeaveEnd() }() ep.Lock() if ep.container != nil { ep.Unlock() return ErrInvalidJoin{} } ep.container = &containerInfo{ id: containerID, config: containerConfig{ hostsPathConfig: hostsPathConfig{ extraHosts: []extraHost{}, parentUpdates: []parentUpdate{}, }, }} ep.joinInfo = &endpointJoinInfo{} container := ep.container network := ep.network epid := ep.id ep.Unlock() defer func() { if err != nil { ep.Lock() ep.container = nil ep.Unlock() } }() network.Lock() driver := network.driver nid := network.id ctrlr := network.ctrlr network.Unlock() ep.processOptions(options...) sboxKey := sandbox.GenerateKey(containerID) if container.config.useDefaultSandBox { sboxKey = sandbox.GenerateKey("default") } err = driver.Join(nid, epid, sboxKey, ep, container.config.generic) if err != nil { return err } defer func() { if err != nil { // Do not alter global err variable, it's needed by the previous defer if err := driver.Leave(nid, epid); err != nil { log.Warnf("driver leave failed while rolling back join: %v", err) } } }() err = ep.buildHostsFiles() if err != nil { return err } err = ep.updateParentHosts() if err != nil { return err } err = ep.setupDNS() if err != nil { return err } sb, err := ctrlr.sandboxAdd(sboxKey, !container.config.useDefaultSandBox, ep) if err != nil { return fmt.Errorf("failed sandbox add: %v", err) } defer func() { if err != nil { ctrlr.sandboxRm(sboxKey, ep) } }() if err := network.ctrlr.updateEndpointToStore(ep); err != nil { return err } container.data.SandboxKey = sb.Key() return nil } func (ep *endpoint) hasInterface(iName string) bool { ep.Lock() defer ep.Unlock() for _, iface := range ep.iFaces { if iface.srcName == iName { return true } } return false } func (ep *endpoint) Leave(containerID string, options ...EndpointOption) error { var err error ep.joinLeaveStart() defer ep.joinLeaveEnd() ep.processOptions(options...) ep.Lock() container := ep.container n := ep.network if container == nil || container.id == "" || container.data.SandboxKey == "" || containerID == "" || container.id != containerID { if container == nil { err = ErrNoContainer{} } else { err = InvalidContainerIDError(containerID) } ep.Unlock() return err } ep.container = nil ep.Unlock() n.Lock() driver := n.driver ctrlr := n.ctrlr n.Unlock() if err := ctrlr.updateEndpointToStore(ep); err != nil { ep.Lock() ep.container = container ep.Unlock() return err } err = driver.Leave(n.id, ep.id) ctrlr.sandboxRm(container.data.SandboxKey, ep) return err } func (ep *endpoint) Delete() error { var err error ep.Lock() epid := ep.id name := ep.name n := ep.network if ep.container != nil { ep.Unlock() return &ActiveContainerError{name: name, id: string(epid)} } n.Lock() ctrlr := n.ctrlr n.Unlock() ep.Unlock() if err = ctrlr.deleteEndpointFromStore(ep); err != nil { return err } defer func() { if err != nil { ep.SetIndex(0) if e := ctrlr.updateEndpointToStore(ep); e != nil { log.Warnf("failed to recreate endpoint in store %s : %v", name, err) } } }() // Update the endpoint count in network and update it in the datastore n.DecEndpointCnt() if err = ctrlr.updateNetworkToStore(n); err != nil { return err } defer func() { if err != nil { n.IncEndpointCnt() if e := ctrlr.updateNetworkToStore(n); e != nil { log.Warnf("failed to update network %s : %v", n.name, e) } } }() if err = ep.deleteEndpoint(); err != nil { return err } return nil } func (ep *endpoint) Statistics() (map[string]*sandbox.InterfaceStatistics, error) { m := make(map[string]*sandbox.InterfaceStatistics) ep.Lock() n := ep.network skey := ep.container.data.SandboxKey ep.Unlock() n.Lock() c := n.ctrlr n.Unlock() sbox := c.sandboxGet(skey) if sbox == nil { return m, nil } var err error for _, i := range sbox.Info().Interfaces() { if m[i.DstName()], err = i.Statistics(); err != nil { return m, err } } return m, nil } func (ep *endpoint) deleteEndpoint() error { ep.Lock() n := ep.network name := ep.name epid := ep.id ep.Unlock() n.Lock() _, ok := n.endpoints[epid] if !ok { n.Unlock() return nil } nid := n.id driver := n.driver delete(n.endpoints, epid) n.Unlock() if err := driver.DeleteEndpoint(nid, epid); err != nil { if _, ok := err.(types.ForbiddenError); ok { n.Lock() n.endpoints[epid] = ep n.Unlock() return err } log.Warnf("driver error deleting endpoint %s : %v", name, err) } n.updateSvcRecord(ep, false) return nil } func (ep *endpoint) addHostEntries(recs []etchosts.Record) { ep.Lock() container := ep.container ep.Unlock() if container == nil { return } if err := etchosts.Add(container.config.hostsPath, recs); err != nil { log.Warnf("Failed adding service host entries to the running container: %v", err) } } func (ep *endpoint) deleteHostEntries(recs []etchosts.Record) { ep.Lock() container := ep.container ep.Unlock() if container == nil { return } if err := etchosts.Delete(container.config.hostsPath, recs); err != nil { log.Warnf("Failed deleting service host entries to the running container: %v", err) } } func (ep *endpoint) buildHostsFiles() error { var extraContent []etchosts.Record ep.Lock() container := ep.container joinInfo := ep.joinInfo ifaces := ep.iFaces n := ep.network ep.Unlock() if container == nil { return ErrNoContainer{} } if container.config.hostsPath == "" { container.config.hostsPath = defaultPrefix + "/" + container.id + "/hosts" } dir, _ := filepath.Split(container.config.hostsPath) err := createBasePath(dir) if err != nil { return err } if joinInfo != nil && joinInfo.hostsPath != "" { content, err := ioutil.ReadFile(joinInfo.hostsPath) if err != nil && !os.IsNotExist(err) { return err } if err == nil { return ioutil.WriteFile(container.config.hostsPath, content, 0644) } } for _, extraHost := range container.config.extraHosts { extraContent = append(extraContent, etchosts.Record{Hosts: extraHost.name, IP: extraHost.IP}) } extraContent = append(extraContent, n.getSvcRecords()...) IP := "" if len(ifaces) != 0 && ifaces[0] != nil { IP = ifaces[0].addr.IP.String() } return etchosts.Build(container.config.hostsPath, IP, container.config.hostName, container.config.domainName, extraContent) } func (ep *endpoint) updateParentHosts() error { ep.Lock() container := ep.container network := ep.network ep.Unlock() if container == nil { return ErrNoContainer{} } for _, update := range container.config.parentUpdates { network.Lock() pep, ok := network.endpoints[types.UUID(update.eid)] if !ok { network.Unlock() continue } network.Unlock() pep.Lock() pContainer := pep.container pep.Unlock() if pContainer != nil { if err := etchosts.Update(pContainer.config.hostsPath, update.ip, update.name); err != nil { return err } } } return nil } func (ep *endpoint) updateDNS(resolvConf []byte) error { ep.Lock() container := ep.container network := ep.network ep.Unlock() if container == nil { return ErrNoContainer{} } oldHash := []byte{} hashFile := container.config.resolvConfPath + ".hash" resolvBytes, err := ioutil.ReadFile(container.config.resolvConfPath) if err != nil { if !os.IsNotExist(err) { return err } } else { oldHash, err = ioutil.ReadFile(hashFile) if err != nil { if !os.IsNotExist(err) { return err } oldHash = []byte{} } } curHash, err := ioutils.HashData(bytes.NewReader(resolvBytes)) if err != nil { return err } if string(oldHash) != "" && curHash != string(oldHash) { // Seems the user has changed the container resolv.conf since the last time // we checked so return without doing anything. return nil } // replace any localhost/127.* and remove IPv6 nameservers if IPv6 disabled. resolvConf, _ = resolvconf.FilterResolvDNS(resolvConf, network.enableIPv6) newHash, err := ioutils.HashData(bytes.NewReader(resolvConf)) if err != nil { return err } // for atomic updates to these files, use temporary files with os.Rename: dir := path.Dir(container.config.resolvConfPath) tmpHashFile, err := ioutil.TempFile(dir, "hash") if err != nil { return err } tmpResolvFile, err := ioutil.TempFile(dir, "resolv") if err != nil { return err } // Change the perms to 0644 since ioutil.TempFile creates it by default as 0600 if err := os.Chmod(tmpResolvFile.Name(), 0644); err != nil { return err } // write the updates to the temp files if err = ioutil.WriteFile(tmpHashFile.Name(), []byte(newHash), 0644); err != nil { return err } if err = ioutil.WriteFile(tmpResolvFile.Name(), resolvConf, 0644); err != nil { return err } // rename the temp files for atomic replace if err = os.Rename(tmpHashFile.Name(), hashFile); err != nil { return err } return os.Rename(tmpResolvFile.Name(), container.config.resolvConfPath) } func copyFile(src, dst string) error { sBytes, err := ioutil.ReadFile(src) if err != nil { return err } return ioutil.WriteFile(dst, sBytes, 0644) } func (ep *endpoint) setupDNS() error { ep.Lock() container := ep.container joinInfo := ep.joinInfo ep.Unlock() if container == nil { return ErrNoContainer{} } if container.config.resolvConfPath == "" { container.config.resolvConfPath = defaultPrefix + "/" + container.id + "/resolv.conf" } dir, _ := filepath.Split(container.config.resolvConfPath) err := createBasePath(dir) if err != nil { return err } if joinInfo.resolvConfPath != "" { if err := copyFile(joinInfo.resolvConfPath, container.config.resolvConfPath); err != nil { return fmt.Errorf("could not copy source resolv.conf file %s to %s: %v", joinInfo.resolvConfPath, container.config.resolvConfPath, err) } return nil } resolvConf, err := resolvconf.Get() if err != nil { return err } if len(container.config.dnsList) > 0 || len(container.config.dnsSearchList) > 0 { var ( dnsList = resolvconf.GetNameservers(resolvConf) dnsSearchList = resolvconf.GetSearchDomains(resolvConf) ) if len(container.config.dnsList) > 0 { dnsList = container.config.dnsList } if len(container.config.dnsSearchList) > 0 { dnsSearchList = container.config.dnsSearchList } return resolvconf.Build(container.config.resolvConfPath, dnsList, dnsSearchList) } return ep.updateDNS(resolvConf) } // EndpointOptionGeneric function returns an option setter for a Generic option defined // in a Dictionary of Key-Value pair func EndpointOptionGeneric(generic map[string]interface{}) EndpointOption { return func(ep *endpoint) { for k, v := range generic { ep.generic[k] = v } } } // JoinOptionPriority function returns an option setter for priority option to // be passed to endpoint Join method. func JoinOptionPriority(prio int) EndpointOption { return func(ep *endpoint) { ep.container.config.prio = prio } } // JoinOptionHostname function returns an option setter for hostname option to // be passed to endpoint Join method. func JoinOptionHostname(name string) EndpointOption { return func(ep *endpoint) { ep.container.config.hostName = name } } // JoinOptionDomainname function returns an option setter for domainname option to // be passed to endpoint Join method. func JoinOptionDomainname(name string) EndpointOption { return func(ep *endpoint) { ep.container.config.domainName = name } } // JoinOptionHostsPath function returns an option setter for hostspath option to // be passed to endpoint Join method. func JoinOptionHostsPath(path string) EndpointOption { return func(ep *endpoint) { ep.container.config.hostsPath = path } } // JoinOptionExtraHost function returns an option setter for extra /etc/hosts options // which is a name and IP as strings. func JoinOptionExtraHost(name string, IP string) EndpointOption { return func(ep *endpoint) { ep.container.config.extraHosts = append(ep.container.config.extraHosts, extraHost{name: name, IP: IP}) } } // JoinOptionParentUpdate function returns an option setter for parent container // which needs to update the IP address for the linked container. func JoinOptionParentUpdate(eid string, name, ip string) EndpointOption { return func(ep *endpoint) { ep.container.config.parentUpdates = append(ep.container.config.parentUpdates, parentUpdate{eid: eid, name: name, ip: ip}) } } // JoinOptionResolvConfPath function returns an option setter for resolvconfpath option to // be passed to endpoint Join method. func JoinOptionResolvConfPath(path string) EndpointOption { return func(ep *endpoint) { ep.container.config.resolvConfPath = path } } // JoinOptionDNS function returns an option setter for dns entry option to // be passed to endpoint Join method. func JoinOptionDNS(dns string) EndpointOption { return func(ep *endpoint) { ep.container.config.dnsList = append(ep.container.config.dnsList, dns) } } // JoinOptionDNSSearch function returns an option setter for dns search entry option to // be passed to endpoint Join method. func JoinOptionDNSSearch(search string) EndpointOption { return func(ep *endpoint) { ep.container.config.dnsSearchList = append(ep.container.config.dnsSearchList, search) } } // JoinOptionUseDefaultSandbox function returns an option setter for using default sandbox to // be passed to endpoint Join method. func JoinOptionUseDefaultSandbox() EndpointOption { return func(ep *endpoint) { ep.container.config.useDefaultSandBox = true } } // CreateOptionExposedPorts function returns an option setter for the container exposed // ports option to be passed to network.CreateEndpoint() method. func CreateOptionExposedPorts(exposedPorts []types.TransportPort) EndpointOption { return func(ep *endpoint) { // Defensive copy eps := make([]types.TransportPort, len(exposedPorts)) copy(eps, exposedPorts) // Store endpoint label and in generic because driver needs it ep.exposedPorts = eps ep.generic[netlabel.ExposedPorts] = eps } } // CreateOptionPortMapping function returns an option setter for the mapping // ports option to be passed to network.CreateEndpoint() method. func CreateOptionPortMapping(portBindings []types.PortBinding) EndpointOption { return func(ep *endpoint) { // Store a copy of the bindings as generic data to pass to the driver pbs := make([]types.PortBinding, len(portBindings)) copy(pbs, portBindings) ep.generic[netlabel.PortMap] = pbs } } // JoinOptionGeneric function returns an option setter for Generic configuration // that is not managed by libNetwork but can be used by the Drivers during the call to // endpoint join method. Container Labels are a good example. func JoinOptionGeneric(generic map[string]interface{}) EndpointOption { return func(ep *endpoint) { ep.container.config.generic = generic } }