[Backport 1.x] allow initial_master_nodes to be disabled

charts/opensearch/CHANGELOG.md

@@ -12,6 +12,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 ### Security
 
+---
+## [1.13.2]
+### Added
+- Add "singleNode" feature to disable the "cluster.initial_master_nodes" env var.
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
 ---
 ## [1.13.1]
 ### Added
@@ -457,7 +466,8 @@ config:
 ### Fixed
 ### Security
 
-[Unreleased]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.13.1...HEAD
+[Unreleased]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.13.2...HEAD
+[1.13.1]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.13.1...opensearch-1.13.2
 [1.13.1]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.13.0...opensearch-1.13.1
 [1.13.0]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.12.1...opensearch-1.13.0
 [1.12.1]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.12.0...opensearch-1.12.1
@@ -503,4 +513,4 @@ config:
 [1.0.6]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.0.5...opensearch-1.0.6
 [1.0.5]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.0.4...opensearch-1.0.5
 [1.0.4]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.0.2...opensearch-1.0.4
-[1.0.2]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.0.1...opensearch-1.0.2
+[1.0.2]: https://github.com/opensearch-project/helm-charts/compare/opensearch-1.0.1...opensearch-1.0.2

charts/opensearch/Chart.yaml

@@ -15,7 +15,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 1.13.1
+version: 1.13.2
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to

charts/opensearch/README.md

@@ -80,6 +80,7 @@ helm uninstall my-release
 | `replicas`                         | Kubernetes replica count for the StatefulSet (i.e. how many pods)                                                                                                                                                                                         | `3`                                             |
 | `resources`                        | Allows you to set the [resources][] for the StatefulSet                                                                                                                                                                                                   | see [values.yaml][]                             |
 | `roles`                            | A list of the specific node [roles][] for the `nodeGroup`                                                                                                                                                                                                | see [values.yaml][]                             |
+| `singleNode`                    |    If `discovery.type` in the opensearch configuration is set to `"single-node"`, this should be set to `true`. If `true`, replicas will be forced to `1`.                                                                                                                                                                                                                    | `false`                                            |
 | `schedulerName`                    | Name of the [alternate scheduler][]                                                                                                                                                                                                                       | `""`                                            |
 | `secretMounts`                     | Allows you easily mount a secret as a file inside the StatefulSet. Useful for mounting certificates and other secrets. See [values.yaml][] for an example                                                                                                 | `[]`                                            |
 | `securityConfig`                   | Configure the opensearch security plugin. There are multiple ways to inject configuration into the chart, see [values.yaml][] details.                           | By default an insecure demonstration configuration is set. This **must** be changed before going to production. |

charts/opensearch/templates/statefulset.yaml

@@ -12,7 +12,11 @@ spec:
   selector:
     matchLabels:
       {{- include "opensearch.selectorLabels" . | nindent 6 }}
+  {{- if .Values.singleNode }}
+  replicas: 1
+  {{- else }}
   replicas: {{ .Values.replicas }}
+  {{- end }}
   podManagementPolicy: {{ .Values.podManagementPolicy }}
   updateStrategy:
     type: {{ .Values.updateStrategy }}
@@ -320,7 +324,7 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.name
-        {{- if has "master" .Values.roles }}
+        {{- if (and (has "master" .Values.roles) (not .Values.singleNode)) }}
         - name: cluster.initial_master_nodes
           value: "{{ template "opensearch.endpoints" . }}"
         {{- end }}
@@ -334,6 +338,10 @@ spec:
           value: "{{ .Values.opensearchJavaOpts }}"
         - name: node.roles
           value: "{{ template "opensearch.roles" . }}"
+        {{- if .Values.singleNode }}
+        - name: discovery.type
+          value: "single-node"
+        {{- end }}
 {{- if .Values.extraEnvs }}
 {{ toYaml .Values.extraEnvs | indent 8 }}
 {{- end }}
@@ -490,4 +498,4 @@ spec:
       {{- else }}
 {{ toYaml .Values.extraContainers | indent 6 }}
       {{- end }}
-      {{- end }}
+      {{- end }}

charts/opensearch/values.yaml

@@ -2,6 +2,11 @@
 clusterName: "opensearch-cluster"
 nodeGroup: "master"
 
+# If discovery.type in the opensearch configuration is set to "single-node",
+# this should be set to "true"
+# If "true", replicas will be forced to 1
+singleNode: false
+
 # The service that non master groups will try to connect to when joining the cluster
 # This should be set to clusterName + "-" + nodeGroup for your master group
 masterService: "opensearch-cluster-master"
@@ -47,6 +52,7 @@ config:
     network.host: 0.0.0.0
 
     # Setting network.host to a non-loopback address enables the annoying bootstrap checks. "Single-node" mode disables them again.
+    # Implicitly done if ".singleNode" is set to "true".
     # discovery.type: single-node
 
     # Start OpenSearch Security Demo Configuration