Exemplo n.º 1
0
// TODO: should take a writer, not []byte
func (writer *NsenterWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
	cmd := "nsenter"
	base_args := []string{
		"--mount=/rootfs/proc/1/ns/mnt",
		"--",
	}

	echo_args := append(base_args, "sh", "-c", fmt.Sprintf("cat > %s", filename))
	glog.V(5).Infof("Command to write data to file: %v %v", cmd, echo_args)
	command := exec.Command(cmd, echo_args...)
	command.Stdin = bytes.NewBuffer(data)
	outputBytes, err := command.CombinedOutput()
	if err != nil {
		glog.Errorf("Output from writing to %q: %v", filename, string(outputBytes))
		return err
	}

	chmod_args := append(base_args, "chmod", fmt.Sprintf("%o", perm), filename)
	glog.V(5).Infof("Command to change permissions to file: %v %v", cmd, chmod_args)
	outputBytes, err = exec.Command(cmd, chmod_args...).CombinedOutput()
	if err != nil {
		glog.Errorf("Output from chmod command: %v", string(outputBytes))
		return err
	}

	return nil
}
Exemplo n.º 2
0
// IsLikelyNotMountPoint determines whether a path is a mountpoint by calling findmnt
// in the host's root mount namespace.
func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
	file, err := filepath.Abs(file)
	if err != nil {
		return true, err
	}

	args := []string{"--mount=/rootfs/proc/1/ns/mnt", "--", n.absHostPath("findmnt"), "-o", "target", "--noheadings", "--target", file}
	glog.V(5).Infof("findmnt command: %v %v", nsenterPath, args)

	exec := exec.New()
	out, err := exec.Command(nsenterPath, args...).CombinedOutput()
	if err != nil {
		glog.Errorf("Failed to nsenter mount, return file doesn't exist: %v", err)
		// If the command itself is correct, then if we encountered error
		// then most likely this means that the directory does not exist.
		return true, os.ErrNotExist
	}
	strOut := strings.TrimSuffix(string(out), "\n")

	glog.V(5).Infof("IsLikelyNotMountPoint findmnt output: %v", strOut)
	if strOut == file {
		return false, nil
	}

	return true, nil
}
Exemplo n.º 3
0
// receive reads result from the decoder in a loop and sends down the result channel.
func (sw *StreamWatcher) receive() {
	defer close(sw.result)
	defer sw.Stop()
	defer util.HandleCrash()
	for {
		action, obj, err := sw.source.Decode()
		if err != nil {
			// Ignore expected error.
			if sw.stopping() {
				return
			}
			switch err {
			case io.EOF:
				// watch closed normally
			case io.ErrUnexpectedEOF:
				glog.V(1).Infof("Unexpected EOF during watch stream event decoding: %v", err)
			default:
				msg := "Unable to decode an event from the watch stream: %v"
				if util.IsProbableEOF(err) {
					glog.V(5).Infof(msg, err)
				} else {
					glog.Errorf(msg, err)
				}
			}
			return
		}
		sw.result <- Event{
			Type:   action,
			Object: obj,
		}
	}
}
Exemplo n.º 4
0
func chooseHostInterfaceFromRoute(inFile io.Reader, nw networkInterfacer) (net.IP, error) {
	routes, err := getRoutes(inFile)
	if err != nil {
		return nil, err
	}
	zero := net.IP{0, 0, 0, 0}
	var finalIP net.IP
	for i := range routes {
		//find interface with gateway
		if routes[i].Destination.Equal(zero) {
			glog.V(4).Infof("Default route transits interface %q", routes[i].Interface)
			finalIP, err := getIPFromInterface(routes[i].Interface, nw)
			if err != nil {
				return nil, err
			}
			if finalIP != nil {
				glog.V(4).Infof("Choosing IP %v ", finalIP)
				return finalIP, nil
			}
		}
	}
	glog.V(4).Infof("No valid IP found")
	if finalIP == nil {
		return nil, fmt.Errorf("Unable to select an IP.")
	}
	return nil, nil
}
Exemplo n.º 5
0
//getFinalIP method receives all the IP addrs of a Interface
//and returns a nil if the address is Loopback, Ipv6, link-local or nil.
//It returns a valid IPv4 if an Ipv4 address is found in the array.
func getFinalIP(addrs []net.Addr) (net.IP, error) {
	if len(addrs) > 0 {
		for i := range addrs {
			glog.V(4).Infof("Checking addr  %s.", addrs[i].String())
			ip, _, err := net.ParseCIDR(addrs[i].String())
			if err != nil {
				return nil, err
			}
			//Only IPv4
			//TODO : add IPv6 support
			if ip.To4() != nil {
				if !ip.IsLoopback() && !ip.IsLinkLocalMulticast() && !ip.IsLinkLocalUnicast() {
					glog.V(4).Infof("IP found %v", ip)
					return ip, nil
				} else {
					glog.V(4).Infof("Loopback/link-local found %v", ip)
				}
			} else {
				glog.V(4).Infof("%v is not a valid IPv4 address", ip)
			}

		}
	}
	return nil, nil
}
Exemplo n.º 6
0
func (t *tcShaper) execAndLog(cmdStr string, args ...string) error {
	glog.V(6).Infof("Running: %s %s", cmdStr, strings.Join(args, " "))
	cmd := t.e.Command(cmdStr, args...)
	out, err := cmd.CombinedOutput()
	glog.V(6).Infof("Output from tc: %s", string(out))
	return err
}
Exemplo n.º 7
0
// doNsenterMount nsenters the host's mount namespace and performs the
// requested mount.
func (n *NsenterMounter) doNsenterMount(source, target, fstype string, options []string) error {
	glog.V(5).Infof("nsenter Mounting %s %s %s %v", source, target, fstype, options)
	args := n.makeNsenterArgs(source, target, fstype, options)

	glog.V(5).Infof("Mount command: %v %v", nsenterPath, args)
	exec := exec.New()
	outputBytes, err := exec.Command(nsenterPath, args...).CombinedOutput()
	if len(outputBytes) != 0 {
		glog.V(5).Infof("Output from mount command: %v", string(outputBytes))
	}

	return err
}
Exemplo n.º 8
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// Decode unmarshals the next object from the underlying stream into the
// provide object, or returns an error.
func (d *YAMLOrJSONDecoder) Decode(into interface{}) error {
	if d.decoder == nil {
		buffer, isJSON := guessJSONStream(d.r, d.bufferSize)
		if isJSON {
			glog.V(4).Infof("decoding stream as JSON")
			d.decoder = json.NewDecoder(buffer)
		} else {
			glog.V(4).Infof("decoding stream as YAML")
			d.decoder = NewYAMLToJSONDecoder(buffer)
		}
	}
	return d.decoder.Decode(into)
}
Exemplo n.º 9
0
// Releases the lock associated with the specified ID.
// Returns an error if the specified ID doesn't exist.
func (km *keyMutex) UnlockKey(id string) error {
	glog.V(5).Infof("UnlockKey(...) called for id %q\r\n", id)
	km.RLock()
	defer km.RUnlock()
	mutex, exists := km.mutexMap[id]
	if !exists {
		return fmt.Errorf("id %q not found", id)
	}
	glog.V(5).Infof("UnlockKey(...) for id. Mutex found, trying to unlock it. %q\r\n", id)

	mutex.Unlock()
	glog.V(5).Infof("UnlockKey(...) for id %q completed.\r\n", id)
	return nil
}
Exemplo n.º 10
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// DebugWrappers wraps a round tripper and logs based on the current log level.
func DebugWrappers(rt http.RoundTripper) http.RoundTripper {
	switch {
	case bool(glog.V(9)):
		rt = newDebuggingRoundTripper(rt, debugCurlCommand, debugURLTiming, debugResponseHeaders)
	case bool(glog.V(8)):
		rt = newDebuggingRoundTripper(rt, debugJustURL, debugRequestHeaders, debugResponseStatus, debugResponseHeaders)
	case bool(glog.V(7)):
		rt = newDebuggingRoundTripper(rt, debugJustURL, debugRequestHeaders, debugResponseStatus)
	case bool(glog.V(6)):
		rt = newDebuggingRoundTripper(rt, debugURLTiming)
	}

	return rt
}
Exemplo n.º 11
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// runs all reload funcs to re-sync iptables rules
func (runner *runner) reload() {
	glog.V(1).Infof("reloading iptables rules")

	for _, f := range runner.reloadFuncs {
		f()
	}
}
Exemplo n.º 12
0
// handle implements a websocket handler.
func (conn *Conn) handle(ws *websocket.Conn) {
	defer conn.Close()
	conn.initialize(ws)

	for {
		conn.resetTimeout()
		var data []byte
		if err := websocket.Message.Receive(ws, &data); err != nil {
			if err != io.EOF {
				glog.Errorf("Error on socket receive: %v", err)
			}
			break
		}
		if len(data) == 0 {
			continue
		}
		channel := data[0]
		if conn.codec == base64Codec {
			channel = channel - '0'
		}
		data = data[1:]
		if int(channel) >= len(conn.channels) {
			glog.V(6).Infof("Frame is targeted for a reader %d that is not valid, possible protocol error", channel)
			continue
		}
		if _, err := conn.channels[channel].DataFromSocket(data); err != nil {
			glog.Errorf("Unable to write frame to %d: %v\n%s", channel, err, string(data))
			continue
		}
	}
}
Exemplo n.º 13
0
// Stream opens a protocol streamer to the server and streams until a client closes
// the connection or the server disconnects.
func (e *streamExecutor) Stream(stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
	supportedProtocols := []string{StreamProtocolV2Name, StreamProtocolV1Name}
	conn, protocol, err := e.Dial(supportedProtocols...)
	if err != nil {
		return err
	}
	defer conn.Close()

	var streamer streamProtocolHandler

	switch protocol {
	case StreamProtocolV2Name:
		streamer = &streamProtocolV2{
			stdin:  stdin,
			stdout: stdout,
			stderr: stderr,
			tty:    tty,
		}
	case "":
		glog.V(4).Infof("The server did not negotiate a streaming protocol version. Falling back to %s", StreamProtocolV1Name)
		fallthrough
	case StreamProtocolV1Name:
		streamer = &streamProtocolV1{
			stdin:  stdin,
			stdout: stdout,
			stderr: stderr,
			tty:    tty,
		}
	}

	return streamer.stream(conn)
}
Exemplo n.º 14
0
// Unmount runs umount(8) in the host's mount namespace.
func (n *NsenterMounter) Unmount(target string) error {
	args := []string{
		"--mount=/rootfs/proc/1/ns/mnt",
		"--",
		n.absHostPath("umount"),
		target,
	}

	glog.V(5).Infof("Unmount command: %v %v", nsenterPath, args)
	exec := exec.New()
	outputBytes, err := exec.Command(nsenterPath, args...).CombinedOutput()
	if len(outputBytes) != 0 {
		glog.V(5).Infof("Output from mount command: %v", string(outputBytes))
	}

	return err
}
Exemplo n.º 15
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func (runner *runner) run(op operation, args []string) ([]byte, error) {
	iptablesCmd := runner.iptablesCommand()

	fullArgs := append(runner.waitFlag, string(op))
	fullArgs = append(fullArgs, args...)
	glog.V(4).Infof("running iptables %s %v", string(op), args)
	return runner.exec.Command(iptablesCmd, fullArgs...).CombinedOutput()
	// Don't log err here - callers might not think it is an error.
}
Exemplo n.º 16
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// Unmount unmounts the target.
func (mounter *Mounter) Unmount(target string) error {
	glog.V(5).Infof("Unmounting %s", target)
	command := exec.Command("umount", target)
	output, err := command.CombinedOutput()
	if err != nil {
		return fmt.Errorf("Unmount failed: %v\nUnmounting arguments: %s\nOutput: %s\n", err, target, string(output))
	}
	return nil
}
Exemplo n.º 17
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// Executes the rule check without using the "-C" flag, instead parsing iptables-save.
// Present for compatibility with <1.4.11 versions of iptables.  This is full
// of hack and half-measures.  We should nix this ASAP.
func (runner *runner) checkRuleWithoutCheck(table Table, chain Chain, args ...string) (bool, error) {
	glog.V(1).Infof("running iptables-save -t %s", string(table))
	out, err := runner.exec.Command(cmdIptablesSave, "-t", string(table)).CombinedOutput()
	if err != nil {
		return false, fmt.Errorf("error checking rule: %v", err)
	}

	// Sadly, iptables has inconsistent quoting rules for comments. Just remove all quotes.
	// Also, quoted multi-word comments (which are counted as a single arg)
	// will be unpacked into multiple args,
	// in order to compare against iptables-save output (which will be split at whitespace boundary)
	// e.g. a single arg('"this must be before the NodePort rules"') will be unquoted and unpacked into 7 args.
	var argsCopy []string
	for i := range args {
		tmpField := strings.Trim(args[i], "\"")
		argsCopy = append(argsCopy, strings.Fields(tmpField)...)
	}
	argset := sets.NewString(argsCopy...)

	for _, line := range strings.Split(string(out), "\n") {
		var fields = strings.Fields(line)

		// Check that this is a rule for the correct chain, and that it has
		// the correct number of argument (+2 for "-A <chain name>")
		if !strings.HasPrefix(line, fmt.Sprintf("-A %s", string(chain))) || len(fields) != len(argsCopy)+2 {
			continue
		}

		// Sadly, iptables has inconsistent quoting rules for comments.
		// Just remove all quotes.
		for i := range fields {
			fields[i] = strings.Trim(fields[i], "\"")
		}

		// TODO: This misses reorderings e.g. "-x foo ! -y bar" will match "! -x foo -y bar"
		if sets.NewString(fields...).IsSuperset(argset) {
			return true, nil
		}
		glog.V(5).Infof("DBG: fields is not a superset of args: fields=%v  args=%v", fields, args)
	}

	return false, nil
}
Exemplo n.º 18
0
func isInterfaceUp(intf *net.Interface) bool {
	if intf == nil {
		return false
	}
	if intf.Flags&net.FlagUp != 0 {
		glog.V(4).Infof("Interface %v is up", intf.Name)
		return true
	}
	return false
}
Exemplo n.º 19
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// baseUrlKey returns the key which urls will be mapped to.
// For example, 127.0.0.1:8080/api/v2/abcde -> 127.0.0.1:8080.
func (b *URLBackoff) baseUrlKey(rawurl *url.URL) string {
	// Simple implementation for now, just the host.
	// We may backoff specific paths (i.e. "pods") differentially
	// in the future.
	host, err := url.Parse(rawurl.String())
	if err != nil {
		glog.V(4).Infof("Error extracting url: %v", rawurl)
		panic("bad url!")
	}
	return host.Host
}
Exemplo n.º 20
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// doMount runs the mount command.
func doMount(source string, target string, fstype string, options []string) error {
	glog.V(5).Infof("Mounting %s %s %s %v", source, target, fstype, options)
	mountArgs := makeMountArgs(source, target, fstype, options)
	command := exec.Command("mount", mountArgs...)
	output, err := command.CombinedOutput()
	if err != nil {
		return fmt.Errorf("Mount failed: %v\nMounting arguments: %s %s %s %v\nOutput: %s\n",
			err, source, target, fstype, options, string(output))
	}
	return err
}
Exemplo n.º 21
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// UpdateBackoff updates backoff metadata
func (b *URLBackoff) UpdateBackoff(actualUrl *url.URL, err error, responseCode int) {
	// range for retry counts that we store is [0,13]
	if responseCode > maxResponseCode || serverIsOverloadedSet.Has(responseCode) {
		b.Backoff.Next(b.baseUrlKey(actualUrl), time.Now())
		return
	} else if responseCode >= 300 || err != nil {
		glog.V(4).Infof("Client is returning errors: code %v, error %v", responseCode, err)
	}

	//If we got this far, there is no backoff required for this URL anymore.
	b.Backoff.Reset(b.baseUrlKey(actualUrl))
}
Exemplo n.º 22
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func init() {
	registered.RegisterVersions(availableVersions...)

	externalVersions := []unversioned.GroupVersion{}
	for _, v := range availableVersions {
		if registered.IsAllowedVersion(v) {
			externalVersions = append(externalVersions, v)
		}
	}
	if len(externalVersions) == 0 {
		glog.V(4).Infof("No version is registered for group %v", componentconfig.GroupName)
		return
	}
	if err := registered.EnableVersions(externalVersions...); err != nil {
		glog.V(4).Infof("%v", err)
		return
	}
	if err := enableVersions(externalVersions); err != nil {
		glog.V(4).Infof("%v", err)
		return
	}
}
Exemplo n.º 23
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func (d *deadlockDetector) runOnce() bool {
	ch := make(chan bool, 1)
	go func() {
		d.lock.Lock()
		d.lock.Unlock()

		ch <- true
	}()
	exitCh := d.exitChannelFn()
	select {
	case <-exitCh:
		d.exiter.Exitf("Deadlock on %s, exiting", d.name)
		// return is here for when we use a fake exiter in testing
		return false
	case <-ch:
		glog.V(6).Infof("%s is not deadlocked", d.name)
	case <-d.stopChannel:
		glog.V(4).Infof("Stopping deadlock detector for %s", d.name)
		return false
	}
	return true
}
Exemplo n.º 24
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func (s *SwaggerSchema) ValidateObject(obj interface{}, fieldName, typeName string) []error {
	allErrs := []error{}
	models := s.api.Models
	model, ok := models.At(typeName)
	if !ok {
		return append(allErrs, fmt.Errorf("couldn't find type: %s", typeName))
	}
	properties := model.Properties
	if len(properties.List) == 0 {
		// The object does not have any sub-fields.
		return nil
	}
	fields, ok := obj.(map[string]interface{})
	if !ok {
		return append(allErrs, fmt.Errorf("field %s: expected object of type map[string]interface{}, but the actual type is %T", fieldName, obj))
	}
	if len(fieldName) > 0 {
		fieldName = fieldName + "."
	}
	// handle required fields
	for _, requiredKey := range model.Required {
		if _, ok := fields[requiredKey]; !ok {
			allErrs = append(allErrs, fmt.Errorf("field %s: is required", requiredKey))
		}
	}
	for key, value := range fields {
		details, ok := properties.At(key)
		if !ok {
			allErrs = append(allErrs, fmt.Errorf("found invalid field %s for %s", key, typeName))
			continue
		}
		if details.Type == nil && details.Ref == nil {
			allErrs = append(allErrs, fmt.Errorf("could not find the type of %s from object: %v", key, details))
		}
		var fieldType string
		if details.Type != nil {
			fieldType = *details.Type
		} else {
			fieldType = *details.Ref
		}
		if value == nil {
			glog.V(2).Infof("Skipping nil field: %s", key)
			continue
		}
		errs := s.validateField(value, fieldName+key, fieldType, &details)
		if len(errs) > 0 {
			allErrs = append(allErrs, errs...)
		}
	}
	return allErrs
}
Exemplo n.º 25
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func getIPFromInterface(intfName string, nw networkInterfacer) (net.IP, error) {
	intf, err := nw.InterfaceByName(intfName)
	if err != nil {
		return nil, err
	}
	if isInterfaceUp(intf) {
		addrs, err := nw.Addrs(intf)
		if err != nil {
			return nil, err
		}
		glog.V(4).Infof("Interface %q has %d addresses :%v.", intfName, len(addrs), addrs)
		finalIP, err := getFinalIP(addrs)
		if err != nil {
			return nil, err
		}
		if finalIP != nil {
			glog.V(4).Infof("valid IPv4 address for interface %q found as %v.", intfName, finalIP)
			return finalIP, nil
		}
	}

	return nil, nil
}
Exemplo n.º 26
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// Body makes the request use obj as the body. Optional.
// If obj is a string, try to read a file of that name.
// If obj is a []byte, send it directly.
// If obj is an io.Reader, use it directly.
// If obj is a runtime.Object, marshal it correctly, and set Content-Type header.
// If obj is a runtime.Object and nil, do nothing.
// Otherwise, set an error.
func (r *Request) Body(obj interface{}) *Request {
	if r.err != nil {
		return r
	}
	switch t := obj.(type) {
	case string:
		data, err := ioutil.ReadFile(t)
		if err != nil {
			r.err = err
			return r
		}
		glog.V(8).Infof("Request Body: %s", string(data))
		r.body = bytes.NewBuffer(data)
	case []byte:
		glog.V(8).Infof("Request Body: %s", string(t))
		r.body = bytes.NewBuffer(t)
	case io.Reader:
		r.body = t
	case runtime.Object:
		// callers may pass typed interface pointers, therefore we must check nil with reflection
		if reflect.ValueOf(t).IsNil() {
			return r
		}
		data, err := runtime.Encode(r.codec, t)
		if err != nil {
			r.err = err
			return r
		}
		glog.V(8).Infof("Request Body: %s", string(data))
		r.body = bytes.NewBuffer(data)
		r.SetHeader("Content-Type", "application/json")
	default:
		r.err = fmt.Errorf("unknown type used for body: %+v", obj)
	}
	return r
}
Exemplo n.º 27
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// transformUnstructuredResponseError handles an error from the server that is not in a structured form.
// It is expected to transform any response that is not recognizable as a clear server sent error from the
// K8S API using the information provided with the request. In practice, HTTP proxies and client libraries
// introduce a level of uncertainty to the responses returned by servers that in common use result in
// unexpected responses. The rough structure is:
//
// 1. Assume the server sends you something sane - JSON + well defined error objects + proper codes
//    - this is the happy path
//    - when you get this output, trust what the server sends
// 2. Guard against empty fields / bodies in received JSON and attempt to cull sufficient info from them to
//    generate a reasonable facsimile of the original failure.
//    - Be sure to use a distinct error type or flag that allows a client to distinguish between this and error 1 above
// 3. Handle true disconnect failures / completely malformed data by moving up to a more generic client error
// 4. Distinguish between various connection failures like SSL certificates, timeouts, proxy errors, unexpected
//    initial contact, the presence of mismatched body contents from posted content types
//    - Give these a separate distinct error type and capture as much as possible of the original message
//
// TODO: introduce transformation of generic http.Client.Do() errors that separates 4.
func (r *Request) transformUnstructuredResponseError(resp *http.Response, req *http.Request, body []byte) error {
	if body == nil && resp.Body != nil {
		if data, err := ioutil.ReadAll(resp.Body); err == nil {
			body = data
		}
	}
	glog.V(8).Infof("Response Body: %s", string(body))

	message := "unknown"
	if isTextResponse(resp) {
		message = strings.TrimSpace(string(body))
	}
	retryAfter, _ := retryAfterSeconds(resp)
	return errors.NewGenericServerResponse(resp.StatusCode, req.Method, unversioned.GroupResource{Group: r.groupVersion.Group, Resource: r.resource}, r.resourceName, message, retryAfter, true)
}
Exemplo n.º 28
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// NewRequest creates a new request helper object for accessing runtime.Objects on a server.
func NewRequest(client HTTPClient, verb string, baseURL *url.URL, groupVersion unversioned.GroupVersion, codec runtime.Codec, backoff BackoffManager) *Request {
	if backoff == nil {
		glog.V(2).Infof("Not implementing request backoff strategy.")
		backoff = &NoBackoff{}
	}
	metrics.Register()
	return &Request{
		client:       client,
		verb:         verb,
		baseURL:      baseURL,
		path:         baseURL.Path,
		groupVersion: groupVersion,
		codec:        codec,
		backoffMgr:   backoff,
	}
}
Exemplo n.º 29
0
// Connects to D-Bus and listens for FirewallD start/restart. (On non-FirewallD-using
// systems, this is effectively a no-op; we listen for the signals, but they will never be
// emitted, so reload() will never be called.)
func (runner *runner) connectToFirewallD() {
	bus, err := runner.dbus.SystemBus()
	if err != nil {
		glog.V(1).Infof("Could not connect to D-Bus system bus: %s", err)
		return
	}

	rule := fmt.Sprintf("type='signal',sender='%s',path='%s',interface='%s',member='Reloaded'", firewalldName, firewalldPath, firewalldInterface)
	bus.BusObject().Call("org.freedesktop.DBus.AddMatch", 0, rule)

	rule = fmt.Sprintf("type='signal',interface='org.freedesktop.DBus',member='NameOwnerChanged',path='/org/freedesktop/DBus',sender='org.freedesktop.DBus',arg0='%s'", firewalldName)
	bus.BusObject().Call("org.freedesktop.DBus.AddMatch", 0, rule)

	runner.signal = make(chan *godbus.Signal, 10)
	bus.Signal(runner.signal)

	go runner.dbusSignalHandler(bus)
}
Exemplo n.º 30
0
func (t *tcShaper) ReconcileInterface() error {
	exists, output, err := t.interfaceExists()
	if err != nil {
		return err
	}
	if !exists {
		glog.V(4).Info("Didn't find bandwidth interface, creating")
		return t.initializeInterface()
	}
	fields := strings.Split(output, " ")
	if len(fields) != 12 || fields[1] != "htb" || fields[2] != "1:" {
		if err := t.deleteInterface(fields[2]); err != nil {
			return err
		}
		return t.initializeInterface()
	}
	return nil
}