Add in the ability to expose the ip address of a container.

container/container.go

@@ -59,6 +59,9 @@ type ContainerHandler interface {
 	// Returns container labels, if available.
 	GetContainerLabels() map[string]string
 
+	// Returns the container's ip address, if available
+	GetContainerIPAddress() string
+
 	// Returns whether the container still exists.
 	Exists() bool
 

container/docker/handler.go

@@ -94,6 +94,9 @@ type dockerContainerHandler struct {
 	// Filesystem handler.
 	fsHandler common.FsHandler
 
+	// The IP address of the container
+	ipAddress string
+
 	ignoreMetrics container.MetricSet
 
 	// thin pool watcher
@@ -222,6 +225,22 @@ func newDockerContainerHandler(
 	handler.networkMode = ctnr.HostConfig.NetworkMode
 	handler.deviceID = ctnr.GraphDriver.Data["DeviceId"]
 
+	// Obtain the IP address for the contianer.
+	// If the NetworkMode starts with 'container:' then we need to use the IP address of the container specified.
+	// This happens in cases such as kubernetes where the containers doesn't have an IP address itself and we need to use the pod's address
+	ipAddress := ctnr.NetworkSettings.IPAddress
+	networkMode := string(ctnr.HostConfig.NetworkMode)
+	if ipAddress == "" && strings.HasPrefix(networkMode, "container:") {
+		containerId := strings.TrimPrefix(networkMode, "container:")
+		c, err := client.ContainerInspect(context.Background(), containerId)
+		if err != nil {
+			return nil, fmt.Errorf("failed to inspect container %q: %v", id, err)
+		}
+		ipAddress = c.NetworkSettings.IPAddress
+	}
+
+	handler.ipAddress = ipAddress
+
 	if !ignoreMetrics.Has(container.DiskUsageMetrics) {
 		handler.fsHandler = &dockerFsHandler{
 			fsHandler:       common.NewFsHandler(time.Minute, rootfsStorageDir, otherStorageDir, fsInfo),
@@ -412,6 +431,10 @@ func (self *dockerContainerHandler) GetContainerLabels() map[string]string {
 	return self.labels
 }
 
+func (self *dockerContainerHandler) GetContainerIPAddress() string {
+	return self.ipAddress
+}
+
 func (self *dockerContainerHandler) ListProcesses(listType container.ListType) ([]int, error) {
 	return containerlibcontainer.GetProcesses(self.cgroupManager)
 }

container/raw/handler.go

@@ -256,6 +256,11 @@ func (self *rawContainerHandler) GetContainerLabels() map[string]string {
 	return map[string]string{}
 }
 
+func (self *rawContainerHandler) GetContainerIPAddress() string {
+	// the IP address for the raw container corresponds to the system ip address.
+	return "127.0.0.1"
+}
+
 func (self *rawContainerHandler) ListContainers(listType container.ListType) ([]info.ContainerReference, error) {
 	return common.ListContainers(self.name, self.cgroupPaths, listType)
 }

container/rkt/handler.go

@@ -250,6 +250,21 @@ func (handler *rktContainerHandler) GetStats() (*info.ContainerStats, error) {
 	return stats, nil
 }
 
+func (self *rktContainerHandler) GetContainerIPAddress() string {
+	// attempt to return the ip address of the pod
+	// if a specific ip address of the pod could not be determined, return the system ip address
+	if self.isPod && len(self.apiPod.Networks) > 0 {
+		address := self.apiPod.Networks[0].Ipv4
+		if address != "" {
+			return address
+		} else {
+			return self.apiPod.Networks[0].Ipv6
+		}
+	} else {
+		return "127.0.0.1"
+	}
+}
+
 func (handler *rktContainerHandler) GetCgroupPath(resource string) (string, error) {
 	path, ok := handler.cgroupPaths[resource]
 	if !ok {

container/testing/mock_handler.go

@@ -96,6 +96,11 @@ func (self *MockContainerHandler) Type() container.ContainerType {
 	return args.Get(0).(container.ContainerType)
 }
 
+func (self *MockContainerHandler) GetContainerIPAddress() string {
+	args := self.Called()
+	return args.Get(0).(string)
+}
+
 type FactoryForMockContainerHandler struct {
 	Name                        string
 	PrepareContainerHandlerFunc func(name string, handler *MockContainerHandler)