Kafka partitioning support (#530)

* Kafka rule extension. Added payload, key and headers for JSON.

* Kafka avro support.

* Adding support for kafka custom partitioning.

Co-authored-by: Mittul Madaan <mittul.madaan@reedelsevier.com>

backend/extensions/Squidex.Extensions/Actions/Kafka/KafkaAction.cs

@@ -36,6 +36,15 @@ namespace Squidex.Extensions.Actions.Kafka
         [Formattable]
         public string Key { get; set; }
 
+        [Display(Name = "Partition Key", Description = "The partition key, only used when we don't want to define partiontionig with key.")]
+        [DataType(DataType.Text)]
+        [Formattable]
+        public string PartitionKey { get; set; }
+
+        [Display(Name = "Partition Count", Description = "Define the number of partitions for specific topic.")]
+        [DataType(DataType.Text)]
+        public int PartitionCount { get; set; }
+
         [Display(Name = "Headers (Optional)", Description = "The message headers in the format '[Key]=[Value]', one entry per line.")]
         [DataType(DataType.MultilineText)]
         [Formattable]

backend/extensions/Squidex.Extensions/Actions/Kafka/KafkaActionHandler.cs

@@ -7,10 +7,8 @@
 
 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using Confluent.Kafka;
 using Squidex.Domain.Apps.Core.HandleRules;
 using Squidex.Domain.Apps.Core.Rules.EnrichedEvents;
 
@@ -55,7 +53,9 @@ namespace Squidex.Extensions.Actions.Kafka
                 MessageKey = key,
                 MessageValue = value,
                 Headers = await ParseHeadersAsync(action.Headers, @event),
-                Schema = action.Schema
+                Schema = action.Schema,
+                PartitionKey = await FormatAsync(action.PartitionKey, @event),
+                PartitionCount = action.PartitionCount
             };
 
             return (Description, ruleJob);
@@ -94,19 +94,7 @@ namespace Squidex.Extensions.Actions.Kafka
         {
             try
             {
-                var message = new Message<string, string> { Key = job.MessageKey, Value = job.MessageValue };
-
-                if (job.Headers?.Count > 0)
-                {
-                    message.Headers = new Headers();
-
-                    foreach (var header in job.Headers)
-                    {
-                        message.Headers.Add(header.Key, Encoding.UTF8.GetBytes(header.Value));
-                    }
-                }
-
-                await kafkaProducer.Send(job.TopicName, message, job.Schema);
+                await kafkaProducer.SendAsync(job);
 
                 return Result.Success($"Event pushed to {job.TopicName} kafka topic.");
             }
@@ -128,5 +116,9 @@ namespace Squidex.Extensions.Actions.Kafka
         public Dictionary<string, string> Headers { get; set; }
 
         public string Schema { get; set; }
+
+        public string PartitionKey { get; set; }
+
+        public int PartitionCount { get; set; }
     }
 }

backend/extensions/Squidex.Extensions/Actions/Kafka/KafkaProducer.cs

@@ -5,7 +5,9 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System;
 using System.Collections.Generic;
+using System.Text;
 using System.Threading.Tasks;
 using Avro;
 using Avro.Generic;
@@ -107,18 +109,48 @@ namespace Squidex.Extensions.Actions.Kafka
                 .WriteProperty("reason", error.Reason));
         }
 
-        public async Task<DeliveryResult<string, string>> Send(string topicName, Message<string, string> message, string schema)
+        public async Task SendAsync(KafkaJob job)
         {
-            if (!string.IsNullOrWhiteSpace(schema))
+            if (!string.IsNullOrWhiteSpace(job.Schema))
             {
-                var value = CreateAvroRecord(message.Value, schema);
+                var value = CreateAvroRecord(job.MessageValue, job.Schema);
 
-                var avroMessage = new Message<string, GenericRecord> { Key = message.Key, Headers = message.Headers, Value = value };
+                var message = new Message<string, GenericRecord> { Value = value };
 
-                await avroProducer.ProduceAsync(topicName, avroMessage);
+                await ProduceAsync(avroProducer, message, job);
             }
+            else
+            {
+                var message = new Message<string, string> { Value = job.MessageValue };
+
+                await ProduceAsync(textProducer, message, job);
+            }
+        }
+
+        private async Task ProduceAsync<T>(IProducer<string, T> producer, Message<string, T> message, KafkaJob job)
+        {
+            message.Key = job.MessageKey;
+
+            if (job.Headers?.Count > 0)
+            {
+                message.Headers = new Headers();
 
-            return await textProducer.ProduceAsync(topicName, message);
+                foreach (var header in job.Headers)
+                {
+                    message.Headers.Add(header.Key, Encoding.UTF8.GetBytes(header.Value));
+                }
+            }
+
+            if (!string.IsNullOrWhiteSpace(job.PartitionKey) && job.PartitionCount > 0)
+            {
+                var partition = Math.Abs(job.PartitionKey.GetHashCode()) % job.PartitionCount;
+
+                await producer.ProduceAsync(new TopicPartition(job.TopicName, partition), message);
+            }
+            else
+            {
+                await producer.ProduceAsync(job.TopicName, message);
+            }
         }
 
         private GenericRecord CreateAvroRecord(string json, string avroSchema)