chore: revert to use ReadWriteOnce as default accessMode to avoid breaking changes (#3070)

Signed-off-by: Derek Wang <[email protected]>

Author: whynowy

docs/core-concepts/inter-step-buffer-service.md

@@ -1,9 +1,13 @@
 # Inter-Step Buffer Service
 
-Inter-Step Buffer Service is the service to provide [Inter-Step Buffers](inter-step-buffer.md).
+Inter-Step Buffer Service is the service to provide
+[Inter-Step Buffers](inter-step-buffer.md).
 
-An Inter-Step Buffer Service is described by a [Custom Resource](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/). It is required to be existing in a namespace before
-Pipeline objects are created. A sample `InterStepBufferService` with JetStream implementation looks like below.
+An Inter-Step Buffer Service is described by a
+[Custom Resource](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/).
+It is required to be existing in a namespace before Pipeline objects are
+created. A sample `InterStepBufferService` with JetStream implementation looks
+like below.
 
 ```yaml
 apiVersion: numaflow.numaproj.io/v1alpha1
@@ -15,9 +19,11 @@ spec:
     version: latest # Do NOT use "latest" but a specific version in your real deployment
 ```
 
-`InterStepBufferService` is a namespaced object. It can be used by all the Pipelines in the same namespace. By default,
-Pipeline objects look for an `InterStepBufferService` named `default`, so a common practice is to create an `InterStepBufferService`
-with the name `default`. If you give the `InterStepBufferService` a name other than `default`, then you need to give the
+`InterStepBufferService` is a namespaced object. It can be used by all the
+Pipelines in the same namespace. By default, Pipeline objects look for an
+`InterStepBufferService` named `default`, so a common practice is to create an
+`InterStepBufferService` with the name `default`. If you give the
+`InterStepBufferService` a name other than `default`, then you need to give the
 same name in the Pipeline spec.
 
 ```yaml
@@ -38,25 +44,29 @@ kubectl get isbsvc
 
 ## JetStream
 
-`JetStream` is one of the supported `Inter-Step Buffer Service` implementations. A keyword `jetstream` under `spec` means
-a JetStream cluster will be created in the namespace.
+`JetStream` is one of the supported `Inter-Step Buffer Service` implementations.
+A keyword `jetstream` under `spec` means a JetStream cluster will be created in
+the namespace.
 
-**For Production Setup**, please make sure you configure [replicas](#replicas), [persistence](#persistence),
-[anti-affinity](#anti-affinity), and [PDB](#pdb).
+**For Production Setup**, please make sure you configure [replicas](#replicas),
+[persistence](#persistence), [anti-affinity](#anti-affinity), and [PDB](#pdb).
 
 ### Version
 
-Property `spec.jetstream.version` is required for a JetStream `InterStepBufferService`. Supported versions can be found
-from the ConfigMap [`numaflow-controller-config`](https://github.com/numaproj/numaflow/blob/main/config/base/controller-manager/numaflow-controller-config.yaml) in the control plane namespace.
+Property `spec.jetstream.version` is required for a JetStream
+`InterStepBufferService`. Supported versions can be found from the ConfigMap
+[`numaflow-controller-config`](https://github.com/numaproj/numaflow/blob/main/config/base/controller-manager/numaflow-controller-config.yaml)
+in the control plane namespace.
 
 **Note**
 
-The version `latest` in the ConfigMap should only be used for testing purpose. It's recommended that you always use a
-fixed version in your real workload.
+The version `latest` in the ConfigMap should only be used for testing purpose.
+It's recommended that you always use a fixed version in your real workload.
 
 ### Replicas
 
-An optional property `spec.jetstream.replicas` (defaults to 3) can be specified, which gives the total number of nodes.
+An optional property `spec.jetstream.replicas` (defaults to 3) can be specified,
+which gives the total number of nodes.
 
 ### Persistence
 
@@ -72,7 +82,7 @@ spec:
     version: latest # Do NOT use "latest" but a specific version in your real deployment
     persistence:
       storageClassName: standard # Optional, will use K8s cluster default storage class if not specified
-      accessMode: ReadWriteOncePod # Optional, defaults to ReadWriteOncePod
+      accessMode: ReadWriteOncePod # Optional, defaults to ReadWriteOnce
       volumeSize: 10Gi # Optional, defaults to 20Gi
 ```
 
@@ -104,7 +114,8 @@ spec:
 
 ### PDB
 
-PDB (Pod Disruption Budget) is essential for running ISB in production to ensure availability.
+PDB (Pod Disruption Budget) is essential for running ISB in production to ensure
+availability.
 
 #### Example PDB Configuration
 
@@ -127,11 +138,13 @@ There are 2 places to configure JetStream settings:
 
 - ConfigMap `numaflow-controller-config` in the control plane namespace.
 
-  This is the default configuration for all the JetStream `InterStepBufferService` created in the Kubernetes cluster.
+  This is the default configuration for all the JetStream
+  `InterStepBufferService` created in the Kubernetes cluster.
 
 - Property `spec.jetstream.settings` in an `InterStepBufferService` object.
 
-  This optional property can be used to override the default configuration defined in the ConfigMap `numaflow-controller-config`.
+  This optional property can be used to override the default configuration
+  defined in the ConfigMap `numaflow-controller-config`.
 
 A sample JetStream configuration:
 
@@ -152,21 +165,27 @@ max_file_store: 1TB
 
 ### Buffer Configuration
 
-For the Inter-Step Buffers created in JetStream ISB Service, there are 2 places to configure the default properties.
+For the Inter-Step Buffers created in JetStream ISB Service, there are 2 places
+to configure the default properties.
 
 - ConfigMap `numaflow-controller-config` in the control plane namespace.
 
-  This is the place to configure the default properties for the streams and consumers created in all the Jet Stream ISB
+  This is the place to configure the default properties for the streams and
+  consumers created in all the Jet Stream ISB
 
 - Services in the Kubernetes cluster.
 
 - Field `spec.jetstream.bufferConfig` in an `InterStepBufferService` object.
 
-  This optional field can be used to customize the stream and consumer properties of that particular `InterStepBufferService`,
+  This optional field can be used to customize the stream and consumer
+  properties of that particular `InterStepBufferService`,
 
-- and the configuration will be merged into the default one from the ConfigMap `numaflow-controller-config`. For example,
-- if you only want to change `maxMsgs` for created streams, then you only need to give `stream.maxMsgs` in the field, all
-- the rest config will still go with the default values in the control plane ConfigMap.
+- and the configuration will be merged into the default one from the ConfigMap
+  `numaflow-controller-config`. For example,
+- if you only want to change `maxMsgs` for created streams, then you only need
+  to give `stream.maxMsgs` in the field, all
+- the rest config will still go with the default values in the control plane
+  ConfigMap.
 
 Both these 2 places expect a YAML format configuration like below:
 
@@ -191,23 +210,28 @@ bufferConfig: |
 
 **Note**
 
-Changing the buffer configuration either in the control plane ConfigMap or in the `InterStepBufferService` object does
-**NOT** make any change to the buffers (streams) already existing.
+Changing the buffer configuration either in the control plane ConfigMap or in
+the `InterStepBufferService` object does **NOT** make any change to the buffers
+(streams) already existing.
 
 ### TLS
 
-`TLS` is optional to configure through `spec.jetstream.tls: true`. Enabling TLS will use a self signed CERT to encrypt
-the connection from Vertex Pods to JetStream service. By default `TLS` is not enabled.
+`TLS` is optional to configure through `spec.jetstream.tls: true`. Enabling TLS
+will use a self signed CERT to encrypt the connection from Vertex Pods to
+JetStream service. By default `TLS` is not enabled.
 
 ### Encryption At Rest
 
-Encryption at rest can be enabled by setting `spec.jetstream.encryption: true`. Be aware this will impact the performance
-a bit, see the detail at [official doc](https://docs.nats.io/running-a-nats-service/nats_admin/jetstream_admin/encryption_at_rest).
+Encryption at rest can be enabled by setting `spec.jetstream.encryption: true`.
+Be aware this will impact the performance a bit, see the detail at
+[official doc](https://docs.nats.io/running-a-nats-service/nats_admin/jetstream_admin/encryption_at_rest).
 
-Once a JetStream ISB Service is created, toggling the `encryption` field will cause problem for the exiting messages, so
-if you want to change the value, please delete and recreate the ISB Service, and you also need to restart all the Vertex
-Pods to pick up the new credentials.
+Once a JetStream ISB Service is created, toggling the `encryption` field will
+cause problem for the exiting messages, so if you want to change the value,
+please delete and recreate the ISB Service, and you also need to restart all the
+Vertex Pods to pick up the new credentials.
 
 ### Other Configuration
 
-Check [here](../APIs.md#numaflow.numaproj.io/v1alpha1.JetStreamBufferService) for the full spec of `spec.jetstream`.
+Check [here](../APIs.md#numaflow.numaproj.io/v1alpha1.JetStreamBufferService)
+for the full spec of `spec.jetstream`.

pkg/apis/numaflow/v1alpha1/persistence_strategy.go

@@ -23,7 +23,7 @@ import (
 )
 
 var DefaultVolumeSize = apiresource.MustParse("20Gi")
-var DefaultAccessMode = corev1.ReadWriteOncePod
+var DefaultAccessMode = corev1.ReadWriteOnce
 
 // PersistenceStrategy defines the strategy of persistence
 type PersistenceStrategy struct {
@@ -46,7 +46,6 @@ func (ps PersistenceStrategy) GetPVCSpec(name string) corev1.PersistentVolumeCla
 	if ps.VolumeSize != nil {
 		volSize = *ps.VolumeSize
 	}
-	// Default to ReadWriteOncePod
 	accessMode := DefaultAccessMode
 	if ps.AccessMode != nil {
 		accessMode = *ps.AccessMode