added option to use emptyDir as additional mount (#512)

related to issue: #484 This commit would allow to add additional volumes as emptyDir, this is necessary if `readOnlyRootFilesystem=true`
opensearch-project · Aug 16, 2023 · ac78faa · ac78faa
2 parents 19c9924 + 7ba69dc
commit ac78faa
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Showing 9 changed files with 127 additions and 2 deletions.
diff --git a/charts/opensearch-operator/files/opensearch.opster.io_opensearchclusters.yaml b/charts/opensearch-operator/files/opensearch.opster.io_opensearchclusters.yaml
@@ -1042,6 +1042,16 @@ spec:
                   additionalVolumes:
                     items:
                       properties:
+                        emptyDir:
+                          description: emptyDir to use to populate the volume
+                          type: object
+                          properties:
+                            sizeLimit:
+                              description: Total amount of local storage required for this EmptyDir volume
+                              type: string
+                            medium:
+                              description: hat type of storage medium should back this directory
+                              type: string
                         configMap:
                           description: ConfigMap to use to populate the volume
                           properties:
@@ -2727,6 +2737,16 @@ spec:
                     description: Additional volumes to mount to all pods in the cluster
                     items:
                       properties:
+                        emptyDir:
+                          description: emptyDir to use to populate the volume
+                          properties:
+                            sizeLimit:
+                              description: Total amount of local storage required for this EmptyDir volume
+                              type: string
+                            medium:
+                              description: hat type of storage medium should back this directory
+                              type: string
+                          type: object
                         configMap:
                           description: ConfigMap to use to populate the volume
                           properties:

diff --git a/docs/designs/crd.md b/docs/designs/crd.md
@@ -221,6 +221,12 @@ GeneralConfig defines global Opensearch cluster configuration
         <td>Snapshot Repo settings</td>
         <td>false</td>
         <td> - </td>
+      </tr><tr>
+        <td><b>additionalVolumes</b></td>
+        <td>[]object</td>
+        <td>List of additional volume mounts</td>
+        <td>false</td>
+        <td>-</td>
       </tr>
 </table>
 
@@ -676,3 +682,51 @@ Every Keystore Value defines a secret to pull secrets from.
       </tr>
     </tbody>
 </table>
+
+<h3 id="GeneralConfig">
+  AdditionalVolume
+</h3>
+
+AdditionalVolume object define additional volume and volumeMount
+<table>
+  <tbody>
+    <tr>
+      <td><b>name</b></td>
+      <td>string</td>
+      <td>Defines name for additional volume</td>
+      <td>true</td>
+      <td>-</td>
+    </tr><tr>
+      <td><b>path</b></td>
+      <td>string</td>
+      <td>Defines mount path for additional volume</td>
+      <td>true</td>
+      <td>-</td>
+    </tr><tr>
+      <td><b>restartPods</b></td>
+      <td>bool</td>
+      <td>Defines if pod should restar or not in case of change in VolumeSource object</td>
+      <td>false</td>
+      <td>false</td>
+    </tr><tr>
+      <td><b>emptyDir</b></td>
+      <td>corev1.EmptyDirVolumeSource</td>
+      <td>Defines emptyDir object to be mouted</td>
+      <td>false</td>
+      <td>-</td>
+    </tr><tr>
+      <td><b>configMap</b></td>
+      <td>corev1.ConfigMapVolumeSource</td>
+      <td>Defines ConfgMap object to be mounted</td>
+      <td>false</td>
+      <td>-</td>
+    </tr><tr>
+      <td><b>secret</b></td>
+      <td>corev1.SecretVolumeSource</td>
+      <td>Defines Secret object to be mounted</td>
+      <td>false</td>
+      <td>-</td>
+    </tr>
+  </tbody>
+</table>
+
diff --git a/docs/userguide/main.md b/docs/userguide/main.md
@@ -694,7 +694,7 @@ spec:
 
 ### Additional Volumes
 
-Sometimes it is neccessary to mount ConfigMaps or Secrets into the Opensearch pods as volumes to provide additional configuration (e.g. plugin config files).  This can be achieved by providing an array of additional volumes to mount to the custom resource. This option is located in either `spec.general.additionalVolumes` or `spec.dashboards.additionalVolumes`.  The format is as follows:
+Sometimes it is neccessary to mount ConfigMaps, Secrets or emptyDir into the Opensearch pods as volumes to provide additional configuration (e.g. plugin config files).  This can be achieved by providing an array of additional volumes to mount to the custom resource. This option is located in either `spec.general.additionalVolumes` or `spec.dashboards.additionalVolumes`.  The format is as follows:
 
 ```yaml
 spec:
@@ -705,6 +705,9 @@ spec:
       configMap:
         name: config-map-name
       restartPods: true #set this to true to restart the pods when the content of the configMap changes
+    - name: temp
+      path: /tmp
+      emptyDir: {}
   dashboards:
     additionalVolumes:
     - name: example-secret

diff --git a/opensearch-operator/api/v1/opensearch_types.go b/opensearch-operator/api/v1/opensearch_types.go
@@ -240,6 +240,8 @@ type AdditionalVolume struct {
 	Secret *corev1.SecretVolumeSource `json:"secret,omitempty"`
 	// ConfigMap to use to populate the volume
 	ConfigMap *corev1.ConfigMapVolumeSource `json:"configMap,omitempty"`
+	// EmptyDir to use to populate the volume
+	EmptyDir *corev1.EmptyDirVolumeSource `json:"emptyDir,omitempty"`
 	// Whether to restart the pods on content change
 	RestartPods bool `json:"restartPods,omitempty"`
 }

diff --git a/opensearch-operator/api/v1/zz_generated.deepcopy.go b/opensearch-operator/api/v1/zz_generated.deepcopy.go
diff --git a/opensearch-operator/config/crd/bases/opensearch.opster.io_opensearchclusters.yaml b/opensearch-operator/config/crd/bases/opensearch.opster.io_opensearchclusters.yaml
@@ -1042,6 +1042,16 @@ spec:
                   additionalVolumes:
                     items:
                       properties:
+                        emptyDir:
+                          description: emptyDir to use to populate the volume
+                          type: object
+                          properties:
+                            sizeLimit:
+                              description: Total amount of local storage required for this EmptyDir volume
+                              type: string
+                            medium:
+                              description: hat type of storage medium should back this directory
+                              type: string
                         configMap:
                           description: ConfigMap to use to populate the volume
                           properties:
@@ -2727,6 +2737,16 @@ spec:
                     description: Additional volumes to mount to all pods in the cluster
                     items:
                       properties:
+                        emptyDir:
+                          description: emptyDir to use to populate the volume
+                          type: object
+                          properties:
+                            sizeLimit:
+                              description: Total amount of local storage required for this EmptyDir volume
+                              type: string
+                            medium:
+                              description: hat type of storage medium should back this directory
+                              type: string
                         configMap:
                           description: ConfigMap to use to populate the volume
                           properties:

diff --git a/opensearch-operator/controllers/cluster_test.go b/opensearch-operator/controllers/cluster_test.go
@@ -172,6 +172,7 @@ var _ = Describe("Cluster Reconciler", func() {
 							HaveVolumeMounts(
 								"test-secret",
 								"test-cm",
+								"test-emptydir",
 							),
 						)),
 						HaveMatchingVolume(And(
@@ -182,6 +183,10 @@ var _ = Describe("Cluster Reconciler", func() {
 							HaveName("test-cm"),
 							HaveVolumeSource("ConfigMap"),
 						)),
+						HaveMatchingVolume(And(
+							HaveName("test-emptydir"),
+							HaveVolumeSource("EmptyDir"),
+						)),
 					))
 				}(nodePool)
 			}

diff --git a/opensearch-operator/controllers/suite_test_helpers.go b/opensearch-operator/controllers/suite_test_helpers.go
@@ -123,6 +123,12 @@ func ComposeOpensearchCrd(clusterName string, namespace string) opsterv1.OpenSea
 						},
 						RestartPods: false,
 					},
+					{
+						Name:        "test-emptydir",
+						Path:        "/tmp/",
+						EmptyDir:    &corev1.EmptyDirVolumeSource{},
+						RestartPods: false,
+					},
 					{
 						Name: "test-cm",
 						Path: "/opt/test-cm",

diff --git a/opensearch-operator/pkg/reconcilers/util/util.go b/opensearch-operator/pkg/reconcilers/util/util.go
@@ -98,6 +98,7 @@ func CreateAdditionalVolumes(
 	namesIndex := map[string]int{}
 
 	for i, volumeConfig := range volumeConfigs {
+		readOnly := true
 		if volumeConfig.ConfigMap != nil {
 			retVolumes = append(retVolumes, corev1.Volume{
 				Name: volumeConfig.Name,
@@ -114,13 +115,22 @@ func CreateAdditionalVolumes(
 				},
 			})
 		}
+		if volumeConfig.EmptyDir != nil {
+			readOnly = false
+			retVolumes = append(retVolumes, corev1.Volume{
+				Name: volumeConfig.Name,
+				VolumeSource: corev1.VolumeSource{
+					EmptyDir: volumeConfig.EmptyDir,
+				},
+			})
+		}
 		if volumeConfig.RestartPods {
 			namesIndex[volumeConfig.Name] = i
 			names = append(names, volumeConfig.Name)
 		}
 		retVolumeMounts = append(retVolumeMounts, corev1.VolumeMount{
 			Name:      volumeConfig.Name,
-			ReadOnly:  true,
+			ReadOnly:  readOnly,
 			MountPath: volumeConfig.Path,
 		})
 	}