Add docs for RocketMQ pubsub (#2469)

* Remove Alibaba and incorporate suggestions

Signed-off-by: Shubham Sharma <shubhash@microsoft.com>

* Update metadata

Signed-off-by: Shubham Sharma <shubhash@microsoft.com>

daprdocs/content/en/reference/components-reference/supported-pubsub/_index.md

@@ -31,6 +31,7 @@ Table captions:
 | [Pulsar]({{< ref setup-pulsar.md >}})                 | Alpha  | v1 | 1.0 |
 | [RabbitMQ]({{< ref setup-rabbitmq.md >}})             | Beta  | v1 | 1.6 |
 | [Redis Streams]({{< ref setup-redis-pubsub.md >}})    | Stable | v1 | 1.0 |
+| [RocketMQ]({{< ref setup-rocketmq.md >}})             | Alpha | v1 | 1.8 |
 
 ### Amazon Web Services (AWS)
 

daprdocs/content/en/reference/components-reference/supported-pubsub/setup-rocketmq.md

@@ -0,0 +1,79 @@
+---
+type: docs
+title: "RocketMQ"
+linkTitle: "RocketMQ"
+description: "Detailed documentation on the RocketMQ pubsub component"
+aliases:
+  - "/operations/components/setup-pubsub/supported-pubsub/setup-rocketmq/"
+---
+
+## Component format
+To setup RocketMQ pubsub, create a component of type `pubsub.rocketmq`. See [this guide]({{< ref "howto-publish-subscribe.md#step-1-setup-the-pubsub-component" >}}) on how to create and apply a pubsub configuration.
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: rocketmq-pubsub
+  namespace: default
+spec:
+  type: pubsub.rocketmq
+  version: v1
+  metadata:
+    - name: nameServer
+      value: "http://localhost:9876"
+    - name: accessKey
+      value: "admin"
+    - name: secretKey
+      value: "password"
+    - name: consumerGroup
+      value: "GID_0001"
+    - name: retries
+      value: 10
+```
+
+{{% alert title="Warning" color="warning" %}}
+The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described [here]({{< ref component-secrets.md >}}).
+{{% /alert %}}
+
+## Spec metadata fields
+| Field              | Required | Details | Example |
+|--------------------|:--------:|--------|---------|
+| accessKey          | N        | Access Key (Username) | `"admin"`
+| secretKey          | N        | Secret Key (Password) | `"password"`
+| nameServer         | N        | Name server address | `"127.0.0.1:9876;127.0.0.2:9877"`
+| nameServerDomain   | N        | Name server domain | `"https://my-app.net:8080/nsaddr"`
+| nameSpace          | N        | Namespace of the producer/consumer | `"namespace"` |
+| groupName          | N        | Producer group name for RocketMQ publishers | `"my_unique_group_name"` |
+| consumerGroup      | N        | Consumer group name for RocketMQ subscribers| `"my_unique_group_name"`
+| content-type       | N        | Message content-type, e.g., `"application/cloudevents+json; charset=utf-8"`, `"application/octet-stream"` | `"text/plain"`
+| retries            | N        | Number of times to retry to connect rocketmq's broker, optional | `0`
+| sendTimeOut        | N        | Timeout duration for publishing a message in nanoseconds | `0`
+
+## Setup RocketMQ
+See https://rocketmq.apache.org/docs/quick-start/ to setup a local RocketMQ instance.
+
+## Per-call metadata fields
+
+### Partition Key
+
+When invoking the RocketMQ pub/sub, it's possible to provide an optional partition key by using the `metadata` query param in the request url.
+
+You need to specify `rocketmq-tag`,`"rocketmq-key"` in `metadata`
+
+Example:
+
+```shell
+curl -X POST http://localhost:3500/v1.0/publish/myRocketMQ/myTopic?metadata.rocketmq-tag=?&metadata.rocketmq-key=? \
+  -H "Content-Type: application/json" \
+  -d '{
+        "data": {
+          "message": "Hi"
+        }
+      }'
+```
+
+## Related links
+- [Basic schema for a Dapr component]({{< ref component-schema >}})
+- [Pub/Sub building block]({{< ref pubsub >}})
+- Read [this guide]({{< ref "howto-publish-subscribe.md#step-2-publish-a-topic" >}}) for instructions on configuring pub/sub components