Attach additional volume for postgres,

config/crd/bases/postgres-operator.crunchydata.com_postgresclusters.yaml

@@ -11027,6 +11027,44 @@ spec:
                       type: array
                     volumes:
                       properties:
+                        additional:
+                          description: Additional pre-existing volumes to add to the
+                            pod.
+                          items:
+                            properties:
+                              claimName:
+                                description: A reference to a preexisting PVC.
+                                type: string
+                              containers:
+                                description: |-
+                                  The containers to attach this volume to.
+                                  A blank/unset `Containers` field matches all containers.
+                                items:
+                                  type: string
+                                maxItems: 10
+                                type: array
+                                x-kubernetes-list-type: atomic
+                              name:
+                                description: |-
+                                  The name of the volume used for mounting path.
+                                  Volumes are mounted in the pods at `volumes/<NAME>`
+                                  Must be unique.
+                                maxLength: 253
+                                minLength: 1
+                                pattern: ^[a-z0-9]([-a-z0-9]*[a-z0-9])?([.][a-z0-9]([-a-z0-9]*[a-z0-9])?)*$
+                                type: string
+                              readOnly:
+                                description: Sets the write/read mode of the volume
+                                type: boolean
+                            required:
+                            - claimName
+                            - name
+                            type: object
+                          maxItems: 10
+                          type: array
+                          x-kubernetes-list-map-keys:
+                          - name
+                          x-kubernetes-list-type: map
                         temp:
                           description: |-
                             An ephemeral volume for temporary files.
@@ -29598,6 +29636,44 @@ spec:
                       type: array
                     volumes:
                       properties:
+                        additional:
+                          description: Additional pre-existing volumes to add to the
+                            pod.
+                          items:
+                            properties:
+                              claimName:
+                                description: A reference to a preexisting PVC.
+                                type: string
+                              containers:
+                                description: |-
+                                  The containers to attach this volume to.
+                                  A blank/unset `Containers` field matches all containers.
+                                items:
+                                  type: string
+                                maxItems: 10
+                                type: array
+                                x-kubernetes-list-type: atomic
+                              name:
+                                description: |-
+                                  The name of the volume used for mounting path.
+                                  Volumes are mounted in the pods at `volumes/<NAME>`
+                                  Must be unique.
+                                maxLength: 253
+                                minLength: 1
+                                pattern: ^[a-z0-9]([-a-z0-9]*[a-z0-9])?([.][a-z0-9]([-a-z0-9]*[a-z0-9])?)*$
+                                type: string
+                              readOnly:
+                                description: Sets the write/read mode of the volume
+                                type: boolean
+                            required:
+                            - claimName
+                            - name
+                            type: object
+                          maxItems: 10
+                          type: array
+                          x-kubernetes-list-map-keys:
+                          - name
+                          x-kubernetes-list-type: map
                         temp:
                           description: |-
                             An ephemeral volume for temporary files.

internal/controller/postgrescluster/instance.go

@@ -1253,6 +1253,11 @@ func (r *Reconciler) reconcileInstance(
 		addDevSHM(&instance.Spec.Template)
 	}
 
+	// mount additional volumes to the Postgres instance containers
+	if err == nil && spec.Volumes != nil && len(spec.Volumes.Additional) > 0 {
+		addAdditionalVolumesToSpecifiedContainers(&instance.Spec.Template, spec.Volumes.Additional)
+	}
+
 	if err == nil {
 		err = errors.WithStack(r.apply(ctx, instance))
 	}

internal/controller/postgrescluster/util.go

@@ -13,9 +13,11 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/apimachinery/pkg/util/sets"
 
 	"github.com/crunchydata/postgres-operator/internal/initialize"
 	"github.com/crunchydata/postgres-operator/internal/naming"
+	"github.com/crunchydata/postgres-operator/pkg/apis/postgres-operator.crunchydata.com/v1beta1"
 )
 
 var tmpDirSizeLimit = resource.MustParse("16Mi")
@@ -285,3 +287,61 @@ func safeHash32(content func(w io.Writer) error) (string, error) {
 	}
 	return rand.SafeEncodeString(fmt.Sprint(hash.Sum32())), nil
 }
+
+// AdditionalVolumeMount returns the name and mount path of the additional volume.
+func AdditionalVolumeMount(name string, readOnly bool) corev1.VolumeMount {
+	return corev1.VolumeMount{
+		Name:      fmt.Sprintf("volumes-%s", name),
+		MountPath: "/volumes/" + name,
+		ReadOnly:  readOnly,
+	}
+}
+
+// addAdditionalVolumesToSpecifiedContainers adds additional volumes to the specified
+// containers in the specified pod
+// addAdditionalVolumesToSpecifiedContainers adds the volumes to the pod
+// as `volumes-<additionalVolumeRequest.Name>`
+// and adds the directory to the path `/volumes/<additionalVolumeRequest.Name>`
+func addAdditionalVolumesToSpecifiedContainers(template *corev1.PodTemplateSpec,
+	additionalVolumes []v1beta1.AdditionalVolume) {
+
+	for _, additionalVolumeRequest := range additionalVolumes {
+
+		additionalVolumeMount := AdditionalVolumeMount(
+			additionalVolumeRequest.Name,
+			additionalVolumeRequest.ReadOnly,
+		)
+
+		additionalVolume := corev1.Volume{
+			Name: additionalVolumeMount.Name,
+			VolumeSource: corev1.VolumeSource{
+				PersistentVolumeClaim: &corev1.PersistentVolumeClaimVolumeSource{
+					ClaimName: additionalVolumeRequest.ClaimName,
+					ReadOnly:  additionalVolumeMount.ReadOnly,
+				},
+			},
+		}
+
+		names := sets.New(additionalVolumeRequest.Containers...)
+
+		for i := range template.Spec.Containers {
+			if names.Len() == 0 || names.Has(template.Spec.Containers[i].Name) {
+				template.Spec.Containers[i].VolumeMounts = append(
+					template.Spec.Containers[i].VolumeMounts,
+					additionalVolumeMount)
+			}
+		}
+
+		for i := range template.Spec.InitContainers {
+			if names.Len() == 0 || names.Has(template.Spec.InitContainers[i].Name) {
+				template.Spec.InitContainers[i].VolumeMounts = append(
+					template.Spec.InitContainers[i].VolumeMounts,
+					additionalVolumeMount)
+			}
+		}
+
+		template.Spec.Volumes = append(
+			template.Spec.Volumes,
+			additionalVolume)
+	}
+}

internal/controller/postgrescluster/util_test.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/crunchydata/postgres-operator/internal/naming"
 	"github.com/crunchydata/postgres-operator/internal/testing/cmp"
+	"github.com/crunchydata/postgres-operator/pkg/apis/postgres-operator.crunchydata.com/v1beta1"
 )
 
 func TestSafeHash32(t *testing.T) {
@@ -378,3 +379,167 @@ func TestJobFailed(t *testing.T) {
 		})
 	}
 }
+
+func TestAddAdditionalVolumesToSpecifiedContainers(t *testing.T) {
+
+	podTemplate := &corev1.PodTemplateSpec{
+		Spec: corev1.PodSpec{
+			InitContainers: []corev1.Container{
+				{Name: "startup"},
+				{Name: "config"},
+			},
+			Containers: []corev1.Container{
+				{Name: "database"},
+				{Name: "other"},
+			}}}
+
+	testCases := []struct {
+		tcName                 string
+		additionalVolumes      []v1beta1.AdditionalVolume
+		expectedContainers     string
+		expectedInitContainers string
+		expectedVolumes        string
+	}{{
+		tcName: "all",
+		additionalVolumes: []v1beta1.AdditionalVolume{{
+			Containers: []string{},
+			ClaimName:  "required",
+			Name:       "required",
+		}},
+		expectedContainers: `- name: database
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+- name: other
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required`,
+		expectedInitContainers: `- name: startup
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+- name: config
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required`,
+		expectedVolumes: `- name: volumes-required
+  persistentVolumeClaim:
+    claimName: required`,
+	}, {
+		tcName: "multiple additional volumes",
+		additionalVolumes: []v1beta1.AdditionalVolume{{
+			Containers: []string{},
+			ClaimName:  "required",
+			Name:       "required",
+		}, {
+			Containers: []string{},
+			ClaimName:  "also",
+			Name:       "other",
+		}},
+		expectedContainers: `- name: database
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+  - mountPath: /volumes/other
+    name: volumes-other
+- name: other
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+  - mountPath: /volumes/other
+    name: volumes-other`,
+		expectedInitContainers: `- name: startup
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+  - mountPath: /volumes/other
+    name: volumes-other
+- name: config
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+  - mountPath: /volumes/other
+    name: volumes-other`,
+		expectedVolumes: `- name: volumes-required
+  persistentVolumeClaim:
+    claimName: required
+- name: volumes-other
+  persistentVolumeClaim:
+    claimName: also`,
+	}, {
+		tcName: "database container only",
+		additionalVolumes: []v1beta1.AdditionalVolume{{
+			Containers: []string{"database"},
+			ClaimName:  "required",
+			Name:       "required",
+		}},
+		expectedContainers: `- name: database
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+- name: other
+  resources: {}`,
+		expectedInitContainers: `- name: startup
+  resources: {}
+- name: config
+  resources: {}`,
+		expectedVolumes: `- name: volumes-required
+  persistentVolumeClaim:
+    claimName: required`,
+	}, {
+		tcName: "readonly",
+		additionalVolumes: []v1beta1.AdditionalVolume{{
+			Containers: []string{"database"},
+			ClaimName:  "required",
+			Name:       "required",
+			ReadOnly:   true,
+		}},
+		expectedContainers: `- name: database
+  resources: {}
+  volumeMounts:
+  - mountPath: /volumes/required
+    name: volumes-required
+    readOnly: true
+- name: other
+  resources: {}`,
+		expectedInitContainers: `- name: startup
+  resources: {}
+- name: config
+  resources: {}`,
+		expectedVolumes: `- name: volumes-required
+  persistentVolumeClaim:
+    claimName: required
+    readOnly: true`,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.tcName, func(t *testing.T) {
+
+			copyPodTemplate := podTemplate.DeepCopy()
+
+			addAdditionalVolumesToSpecifiedContainers(
+				copyPodTemplate,
+				tc.additionalVolumes,
+			)
+
+			assert.Assert(t, cmp.MarshalMatches(
+				copyPodTemplate.Spec.Containers,
+				tc.expectedContainers))
+			assert.Assert(t, cmp.MarshalMatches(
+				copyPodTemplate.Spec.InitContainers,
+				tc.expectedInitContainers))
+			assert.Assert(t, cmp.MarshalMatches(
+				copyPodTemplate.Spec.Volumes,
+				tc.expectedVolumes))
+		})
+	}
+}

pkg/apis/postgres-operator.crunchydata.com/v1/postgrescluster_types.go

@@ -534,6 +534,14 @@ type PostgresVolumesSpec struct {
 	// ---
 	// +optional
 	Temp *v1beta1.VolumeClaimSpec `json:"temp,omitempty"`
+
+	// Additional pre-existing volumes to add to the pod.
+	// ---
+	// +optional
+	// +listType=map
+	// +listMapKey=name
+	// +kubebuilder:validation:MaxItems=10
+	Additional []v1beta1.AdditionalVolume `json:"additional,omitempty"`
 }
 
 type TablespaceVolume struct {