| /* |
| Copyright 2015 The Kubernetes Authors. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| package downwardapi |
| |
| import ( |
| "fmt" |
| "path/filepath" |
| |
| "k8s.io/api/core/v1" |
| "k8s.io/apimachinery/pkg/types" |
| utilerrors "k8s.io/apimachinery/pkg/util/errors" |
| "k8s.io/kubernetes/pkg/api/v1/resource" |
| "k8s.io/kubernetes/pkg/fieldpath" |
| utilstrings "k8s.io/kubernetes/pkg/util/strings" |
| "k8s.io/kubernetes/pkg/volume" |
| volumeutil "k8s.io/kubernetes/pkg/volume/util" |
| |
| "k8s.io/klog" |
| ) |
| |
| // ProbeVolumePlugins is the entry point for plugin detection in a package. |
| func ProbeVolumePlugins() []volume.VolumePlugin { |
| return []volume.VolumePlugin{&downwardAPIPlugin{}} |
| } |
| |
| const ( |
| downwardAPIPluginName = "kubernetes.io/downward-api" |
| ) |
| |
| // downwardAPIPlugin implements the VolumePlugin interface. |
| type downwardAPIPlugin struct { |
| host volume.VolumeHost |
| } |
| |
| var _ volume.VolumePlugin = &downwardAPIPlugin{} |
| |
| func wrappedVolumeSpec() volume.Spec { |
| return volume.Spec{ |
| Volume: &v1.Volume{VolumeSource: v1.VolumeSource{EmptyDir: &v1.EmptyDirVolumeSource{Medium: v1.StorageMediumMemory}}}, |
| } |
| } |
| |
| func (plugin *downwardAPIPlugin) Init(host volume.VolumeHost) error { |
| plugin.host = host |
| return nil |
| } |
| |
| func (plugin *downwardAPIPlugin) GetPluginName() string { |
| return downwardAPIPluginName |
| } |
| |
| func (plugin *downwardAPIPlugin) GetVolumeName(spec *volume.Spec) (string, error) { |
| volumeSource, _ := getVolumeSource(spec) |
| if volumeSource == nil { |
| return "", fmt.Errorf("Spec does not reference a DownwardAPI volume type") |
| } |
| |
| // Return user defined volume name, since this is an ephemeral volume type |
| return spec.Name(), nil |
| } |
| |
| func (plugin *downwardAPIPlugin) CanSupport(spec *volume.Spec) bool { |
| return spec.Volume != nil && spec.Volume.DownwardAPI != nil |
| } |
| |
| func (plugin *downwardAPIPlugin) RequiresRemount() bool { |
| return true |
| } |
| |
| func (plugin *downwardAPIPlugin) SupportsMountOption() bool { |
| return false |
| } |
| |
| func (plugin *downwardAPIPlugin) SupportsBulkVolumeVerification() bool { |
| return false |
| } |
| |
| func (plugin *downwardAPIPlugin) NewMounter(spec *volume.Spec, pod *v1.Pod, opts volume.VolumeOptions) (volume.Mounter, error) { |
| v := &downwardAPIVolume{ |
| volName: spec.Name(), |
| items: spec.Volume.DownwardAPI.Items, |
| pod: pod, |
| podUID: pod.UID, |
| plugin: plugin, |
| } |
| return &downwardAPIVolumeMounter{ |
| downwardAPIVolume: v, |
| source: *spec.Volume.DownwardAPI, |
| opts: &opts, |
| }, nil |
| } |
| |
| func (plugin *downwardAPIPlugin) NewUnmounter(volName string, podUID types.UID) (volume.Unmounter, error) { |
| return &downwardAPIVolumeUnmounter{ |
| &downwardAPIVolume{ |
| volName: volName, |
| podUID: podUID, |
| plugin: plugin, |
| }, |
| }, nil |
| } |
| |
| func (plugin *downwardAPIPlugin) ConstructVolumeSpec(volumeName, mountPath string) (*volume.Spec, error) { |
| downwardAPIVolume := &v1.Volume{ |
| Name: volumeName, |
| VolumeSource: v1.VolumeSource{ |
| DownwardAPI: &v1.DownwardAPIVolumeSource{}, |
| }, |
| } |
| return volume.NewSpecFromVolume(downwardAPIVolume), nil |
| } |
| |
| // downwardAPIVolume retrieves downward API data and placing them into the volume on the host. |
| type downwardAPIVolume struct { |
| volName string |
| items []v1.DownwardAPIVolumeFile |
| pod *v1.Pod |
| podUID types.UID // TODO: remove this redundancy as soon NewUnmounter func will have *v1.POD and not only types.UID |
| plugin *downwardAPIPlugin |
| volume.MetricsNil |
| } |
| |
| // downwardAPIVolumeMounter fetches info from downward API from the pod |
| // and dumps it in files |
| type downwardAPIVolumeMounter struct { |
| *downwardAPIVolume |
| source v1.DownwardAPIVolumeSource |
| opts *volume.VolumeOptions |
| } |
| |
| // downwardAPIVolumeMounter implements volume.Mounter interface |
| var _ volume.Mounter = &downwardAPIVolumeMounter{} |
| |
| // downward API volumes are always ReadOnlyManaged |
| func (d *downwardAPIVolume) GetAttributes() volume.Attributes { |
| return volume.Attributes{ |
| ReadOnly: true, |
| Managed: true, |
| SupportsSELinux: true, |
| } |
| } |
| |
| // Checks prior to mount operations to verify that the required components (binaries, etc.) |
| // to mount the volume are available on the underlying node. |
| // If not, it returns an error |
| func (b *downwardAPIVolumeMounter) CanMount() error { |
| return nil |
| } |
| |
| // SetUp puts in place the volume plugin. |
| // This function is not idempotent by design. We want the data to be refreshed periodically. |
| // The internal sync interval of kubelet will drive the refresh of data. |
| // TODO: Add volume specific ticker and refresh loop |
| func (b *downwardAPIVolumeMounter) SetUp(fsGroup *int64) error { |
| return b.SetUpAt(b.GetPath(), fsGroup) |
| } |
| |
| func (b *downwardAPIVolumeMounter) SetUpAt(dir string, fsGroup *int64) error { |
| klog.V(3).Infof("Setting up a downwardAPI volume %v for pod %v/%v at %v", b.volName, b.pod.Namespace, b.pod.Name, dir) |
| // Wrap EmptyDir. Here we rely on the idempotency of the wrapped plugin to avoid repeatedly mounting |
| wrapped, err := b.plugin.host.NewWrapperMounter(b.volName, wrappedVolumeSpec(), b.pod, *b.opts) |
| if err != nil { |
| klog.Errorf("Couldn't setup downwardAPI volume %v for pod %v/%v: %s", b.volName, b.pod.Namespace, b.pod.Name, err.Error()) |
| return err |
| } |
| |
| data, err := CollectData(b.source.Items, b.pod, b.plugin.host, b.source.DefaultMode) |
| if err != nil { |
| klog.Errorf("Error preparing data for downwardAPI volume %v for pod %v/%v: %s", b.volName, b.pod.Namespace, b.pod.Name, err.Error()) |
| return err |
| } |
| |
| setupSuccess := false |
| if err := wrapped.SetUpAt(dir, fsGroup); err != nil { |
| klog.Errorf("Unable to setup downwardAPI volume %v for pod %v/%v: %s", b.volName, b.pod.Namespace, b.pod.Name, err.Error()) |
| return err |
| } |
| |
| if err := volumeutil.MakeNestedMountpoints(b.volName, dir, *b.pod); err != nil { |
| return err |
| } |
| |
| defer func() { |
| // Clean up directories if setup fails |
| if !setupSuccess { |
| unmounter, unmountCreateErr := b.plugin.NewUnmounter(b.volName, b.podUID) |
| if unmountCreateErr != nil { |
| klog.Errorf("error cleaning up mount %s after failure. Create unmounter failed with %v", b.volName, unmountCreateErr) |
| return |
| } |
| tearDownErr := unmounter.TearDown() |
| if tearDownErr != nil { |
| klog.Errorf("error tearing down volume %s with : %v", b.volName, tearDownErr) |
| } |
| } |
| }() |
| |
| writerContext := fmt.Sprintf("pod %v/%v volume %v", b.pod.Namespace, b.pod.Name, b.volName) |
| writer, err := volumeutil.NewAtomicWriter(dir, writerContext) |
| if err != nil { |
| klog.Errorf("Error creating atomic writer: %v", err) |
| return err |
| } |
| |
| err = writer.Write(data) |
| if err != nil { |
| klog.Errorf("Error writing payload to dir: %v", err) |
| return err |
| } |
| |
| err = volume.SetVolumeOwnership(b, fsGroup) |
| if err != nil { |
| klog.Errorf("Error applying volume ownership settings for group: %v", fsGroup) |
| return err |
| } |
| |
| setupSuccess = true |
| return nil |
| } |
| |
| // CollectData collects requested downwardAPI in data map. |
| // Map's key is the requested name of file to dump |
| // Map's value is the (sorted) content of the field to be dumped in the file. |
| // |
| // Note: this function is exported so that it can be called from the projection volume driver |
| func CollectData(items []v1.DownwardAPIVolumeFile, pod *v1.Pod, host volume.VolumeHost, defaultMode *int32) (map[string]volumeutil.FileProjection, error) { |
| if defaultMode == nil { |
| return nil, fmt.Errorf("No defaultMode used, not even the default value for it") |
| } |
| |
| errlist := []error{} |
| data := make(map[string]volumeutil.FileProjection) |
| for _, fileInfo := range items { |
| var fileProjection volumeutil.FileProjection |
| fPath := filepath.Clean(fileInfo.Path) |
| if fileInfo.Mode != nil { |
| fileProjection.Mode = *fileInfo.Mode |
| } else { |
| fileProjection.Mode = *defaultMode |
| } |
| if fileInfo.FieldRef != nil { |
| // TODO: unify with Kubelet.podFieldSelectorRuntimeValue |
| if values, err := fieldpath.ExtractFieldPathAsString(pod, fileInfo.FieldRef.FieldPath); err != nil { |
| klog.Errorf("Unable to extract field %s: %s", fileInfo.FieldRef.FieldPath, err.Error()) |
| errlist = append(errlist, err) |
| } else { |
| fileProjection.Data = []byte(values) |
| } |
| } else if fileInfo.ResourceFieldRef != nil { |
| containerName := fileInfo.ResourceFieldRef.ContainerName |
| nodeAllocatable, err := host.GetNodeAllocatable() |
| if err != nil { |
| errlist = append(errlist, err) |
| } else if values, err := resource.ExtractResourceValueByContainerNameAndNodeAllocatable(fileInfo.ResourceFieldRef, pod, containerName, nodeAllocatable); err != nil { |
| klog.Errorf("Unable to extract field %s: %s", fileInfo.ResourceFieldRef.Resource, err.Error()) |
| errlist = append(errlist, err) |
| } else { |
| fileProjection.Data = []byte(values) |
| } |
| } |
| |
| data[fPath] = fileProjection |
| } |
| return data, utilerrors.NewAggregate(errlist) |
| } |
| |
| func (d *downwardAPIVolume) GetPath() string { |
| return d.plugin.host.GetPodVolumeDir(d.podUID, utilstrings.EscapeQualifiedNameForDisk(downwardAPIPluginName), d.volName) |
| } |
| |
| // downwardAPIVolumeCleaner handles cleaning up downwardAPI volumes |
| type downwardAPIVolumeUnmounter struct { |
| *downwardAPIVolume |
| } |
| |
| // downwardAPIVolumeUnmounter implements volume.Unmounter interface |
| var _ volume.Unmounter = &downwardAPIVolumeUnmounter{} |
| |
| func (c *downwardAPIVolumeUnmounter) TearDown() error { |
| return c.TearDownAt(c.GetPath()) |
| } |
| |
| func (c *downwardAPIVolumeUnmounter) TearDownAt(dir string) error { |
| return volumeutil.UnmountViaEmptyDir(dir, c.plugin.host, c.volName, wrappedVolumeSpec(), c.podUID) |
| } |
| |
| func getVolumeSource(spec *volume.Spec) (*v1.DownwardAPIVolumeSource, bool) { |
| var readOnly bool |
| var volumeSource *v1.DownwardAPIVolumeSource |
| |
| if spec.Volume != nil && spec.Volume.DownwardAPI != nil { |
| volumeSource = spec.Volume.DownwardAPI |
| readOnly = spec.ReadOnly |
| } |
| |
| return volumeSource, readOnly |
| } |