Merge pull request #12440 from umohnani8/cm

Add support for configmap volumes to play kube

2 files changed, 69 insertions, 7 deletions

diff --git a/pkg/specgen/generate/kube/kube.go b/pkg/specgen/generate/kube/kube.go
index c502a6e62..6d9f598c9 100644
--- a/pkg/specgen/generate/kube/kube.go
+++ b/pkg/specgen/generate/kube/kube.go
@@ -310,6 +310,11 @@ func ToSpecGen(ctx context.Context, opts *CtrSpecGenOptions) (*specgen.SpecGener
 		if !exists {
 			return nil, errors.Errorf("Volume mount %s specified for container but not configured in volumes", volume.Name)
 		}
+		// Skip if the volume is optional. This means that a configmap for a configmap volume was not found but it was
+		// optional so we can move on without throwing an error
+		if exists && volumeSource.Optional {
+			continue
+		}
 
 		dest, options, err := parseMountPath(volume.MountPath, volume.ReadOnly)
 		if err != nil {
@@ -341,6 +346,13 @@ func ToSpecGen(ctx context.Context, opts *CtrSpecGenOptions) (*specgen.SpecGener
 				Options: options,
 			}
 			s.Volumes = append(s.Volumes, &namedVolume)
+		case KubeVolumeTypeConfigMap:
+			cmVolume := specgen.NamedVolume{
+				Dest:    volume.MountPath,
+				Name:    volumeSource.Source,
+				Options: options,
+			}
+			s.Volumes = append(s.Volumes, &cmVolume)
 		default:
 			return nil, errors.Errorf("Unsupported volume source type")
 		}
diff --git a/pkg/specgen/generate/kube/volume.go b/pkg/specgen/generate/kube/volume.go
index a8042b532..76ec0a390 100644
--- a/pkg/specgen/generate/kube/volume.go
+++ b/pkg/specgen/generate/kube/volume.go
@@ -23,6 +23,7 @@ type KubeVolumeType int
 const (
 	KubeVolumeTypeBindMount KubeVolumeType = iota
 	KubeVolumeTypeNamed     KubeVolumeType = iota
+	KubeVolumeTypeConfigMap KubeVolumeType = iota
 )
 
 // nolint:golint
@@ -31,6 +32,14 @@ type KubeVolume struct {
 	Type KubeVolumeType
 	// Path for bind mount or volume name for named volume
 	Source string
+	// Items to add to a named volume created where the key is the file name and the value is the data
+	// This is only used when there are volumes in the yaml that refer to a configmap
+	// Example: if configmap has data "SPECIAL_LEVEL: very" then the file name is "SPECIAL_LEVEL" and the
+	// data in that file is "very".
+	Items map[string]string
+	// If the volume is optional, we can move on if it is not found
+	// Only used when there are volumes in a yaml that refer to a configmap
+	Optional bool
 }
 
 // Create a KubeVolume from an HostPathVolumeSource
@@ -98,23 +107,64 @@ func VolumeFromPersistentVolumeClaim(claim *v1.PersistentVolumeClaimVolumeSource
 	}, nil
 }
 
+func VolumeFromConfigMap(configMapVolumeSource *v1.ConfigMapVolumeSource, configMaps []v1.ConfigMap) (*KubeVolume, error) {
+	var configMap *v1.ConfigMap
+	kv := &KubeVolume{Type: KubeVolumeTypeConfigMap, Items: map[string]string{}}
+	for _, cm := range configMaps {
+		if cm.Name == configMapVolumeSource.Name {
+			matchedCM := cm
+			// Set the source to the config map name
+			kv.Source = cm.Name
+			configMap = &matchedCM
+			break
+		}
+	}
+
+	if configMap == nil {
+		// If the volumeSource was optional, move on even if a matching configmap wasn't found
+		if *configMapVolumeSource.Optional {
+			kv.Source = configMapVolumeSource.Name
+			kv.Optional = *configMapVolumeSource.Optional
+			return kv, nil
+		}
+		return nil, errors.Errorf("no such ConfigMap %q", configMapVolumeSource.Name)
+	}
+
+	// If there are Items specified in the volumeSource, that overwrites the Data from the configmap
+	if len(configMapVolumeSource.Items) > 0 {
+		for _, item := range configMapVolumeSource.Items {
+			if val, ok := configMap.Data[item.Key]; ok {
+				kv.Items[item.Path] = val
+			}
+		}
+	} else {
+		for k, v := range configMap.Data {
+			kv.Items[k] = v
+		}
+	}
+	return kv, nil
+}
+
 // Create a KubeVolume from one of the supported VolumeSource
-func VolumeFromSource(volumeSource v1.VolumeSource) (*KubeVolume, error) {
-	if volumeSource.HostPath != nil {
+func VolumeFromSource(volumeSource v1.VolumeSource, configMaps []v1.ConfigMap) (*KubeVolume, error) {
+	switch {
+	case volumeSource.HostPath != nil:
 		return VolumeFromHostPath(volumeSource.HostPath)
-	} else if volumeSource.PersistentVolumeClaim != nil {
+	case volumeSource.PersistentVolumeClaim != nil:
 		return VolumeFromPersistentVolumeClaim(volumeSource.PersistentVolumeClaim)
-	} else {
-		return nil, errors.Errorf("HostPath and PersistentVolumeClaim are currently the only supported VolumeSource")
+	case volumeSource.ConfigMap != nil:
+		return VolumeFromConfigMap(volumeSource.ConfigMap, configMaps)
+	default:
+		return nil, errors.Errorf("HostPath, ConfigMap, and PersistentVolumeClaim are currently the only supported VolumeSource")
 	}
 }
 
 // Create a map of volume name to KubeVolume
-func InitializeVolumes(specVolumes []v1.Volume) (map[string]*KubeVolume, error) {
+func InitializeVolumes(specVolumes []v1.Volume, configMaps []v1.ConfigMap) (map[string]*KubeVolume, error) {
 	volumes := make(map[string]*KubeVolume)
 
 	for _, specVolume := range specVolumes {
-		volume, err := VolumeFromSource(specVolume.VolumeSource)
+		volume, err := VolumeFromSource(specVolume.VolumeSource, configMaps)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to create volume %q", specVolume.Name)
 		}