feat: Add SubPathExpr option for additionalVolumes

Author: smutel

docs/reference/cluster_manifest.md

@@ -226,7 +226,8 @@ These parameters are grouped directly under  the `spec` key in the manifest.
   [kubernetes volumeSource](https://godoc.org/k8s.io/api/core/v1#VolumeSource).
   It allows you to mount existing PersistentVolumeClaims, ConfigMaps and Secrets inside the StatefulSet.
   Also an `emptyDir` volume can be shared between initContainer and statefulSet.
-  Additionaly, you can provide a `SubPath` for volume mount (a file in a configMap source volume, for example).
+  Additionaly, you can provide a `SubPath` for volume mount (a file in a configMap source volume, for example) 
+  or a `SubPathExpr`.
   You can also specify in which container the additional Volumes will be mounted with the `targetContainers` array option.
   If `targetContainers` is empty, additional volumes will be mounted only in the `postgres` container.
   If you set the `all` special item, it will be mounted in all containers (postgres + sidecars).

manifests/complete-postgres-manifest.yaml

@@ -81,6 +81,15 @@ spec:
 #        PersistentVolumeClaim:
 #          claimName: pvc-postgresql-data-partitions
 #          readyOnly: false
+#    - name: data
+#      mountPath: /home/postgres/pgdata/partitions
+#      subPathExpr: $(NODE_NAME)/$(POD_NAME)
+#      targetContainers:
+#        - postgres
+#      volumeSource:
+#        PersistentVolumeClaim:
+#          claimName: pvc-postgresql-data-partitions
+#          readyOnly: false
 #    - name: conf
 #      mountPath: /etc/telegraf
 #      subPath: telegraf.conf

manifests/postgresql.crd.yaml

@@ -97,8 +97,11 @@ spec:
                     volumeSource:
                       type: object
                       x-kubernetes-preserve-unknown-fields: true
-                    subPath:
-                      type: string
+                    oneOff:
+                      - properties:
+                          subPath: string
+                      - properties:
+                          subPathExpr: string
               allowedSourceRanges:
                 type: array
                 nullable: true

pkg/apis/acid.zalan.do/v1/crds.go

@@ -167,6 +167,9 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 									"subPath": {
 										Type: "string",
 									},
+									"subPathExpr": {
+										Type: "string",
+									},
 								},
 							},
 						},

pkg/apis/acid.zalan.do/v1/postgresql_type.go

@@ -141,6 +141,7 @@ type AdditionalVolume struct {
 	Name             string          `json:"name"`
 	MountPath        string          `json:"mountPath"`
 	SubPath          string          `json:"subPath,omitempty"`
+	SubPathExpr      string          `json:"subPathExpr,omitemtpy"`
 	TargetContainers []string        `json:"targetContainers"`
 	VolumeSource     v1.VolumeSource `json:"volumeSource"`
 }

pkg/apis/zalando.org/v1/zz_generated.deepcopy.go

@@ -1752,9 +1752,10 @@ func (c *Cluster) addAdditionalVolumes(podSpec *v1.PodSpec,
 			for _, target := range additionalVolume.TargetContainers {
 				if podSpec.Containers[i].Name == target || target == "all" {
 					mounts = append(mounts, v1.VolumeMount{
-						Name:      additionalVolume.Name,
-						MountPath: additionalVolume.MountPath,
-						SubPath:   additionalVolume.SubPath,
+						Name:        additionalVolume.Name,
+						MountPath:   additionalVolume.MountPath,
+						SubPath:     additionalVolume.SubPath,
+						SubPathExpr: additionalVolume.SubPathExpr,
 					})
 				}
 			}