kafka: document numPartitions in pubsub and bindings metadata

Signed-off-by: akshitguptaa <akshitguptaa29@gmail.com>

Author: Akshitguptaa

bindings/kafka/metadata.yaml

@@ -342,6 +342,20 @@ metadata:
       The maximum size in bytes allowed for a single Kafka message.
     example: '2048'
     default: '1024'
+  - name: numPartitions
+    type: number
+    description: |
+      If set to a value greater than 0, dapr will create the topic with
+      this many partitions if it does not already exist. If unset
+      (default), dapr does not create topics; this is left to the
+      Kafka broker's own auto-create behavior or external provisioning.
+    example: '3'
+  - name: replicationFactor
+    type: number
+    description: |
+      Replication factor used when numPartitions is set and dapr
+      creates the topic. Defaults to 1.
+    example: '3'
   - name: consumeRetryInterval
     type: duration
     description: |

common/component/kafka/metadata.go

@@ -382,7 +382,7 @@ func (k *Kafka) getKafkaMetadata(meta map[string]string) (*KafkaMetadata, error)
 	if m.NumPartitions < 0 {
 		return nil, errors.New("kafka error: 'numPartitions' must be a non-negative number")
 	}
-	if m.NumPartitions > 0 && strings.ToLower(m.AuthType) == awsIAMAuthType {
+	if m.NumPartitions > 0 && strings.EqualFold(m.AuthType, awsIAMAuthType) {
 		return nil, errors.New("kafka error: 'numPartitions' auto-topic-creation is not supported with authType 'awsiam'")
 	}
 	if m.NumPartitions > 0 && m.ReplicationFactor <= 0 {

pubsub/kafka/metadata.yaml

@@ -303,6 +303,20 @@ metadata:
         The maximum size in bytes allowed for a single Kafka message.
       example: '2048'
       default: '1024'
+    - name: numPartitions
+      type: number
+      description: |
+        If set to a value greater than 0, dapr will create the topic with
+        this many partitions if it does not already exist. If unset
+        (default), dapr does not create topics; this is left to the
+        Kafka broker's own auto-create behavior or external provisioning.
+      example: '3'
+    - name: replicationFactor
+      type: number
+      description: |
+        Replication factor used when numPartitions is set and dapr
+        creates the topic. Defaults to 1.
+      example: '3'
     - name: consumeRetryInterval
       type: duration
       description: |