1.Basic Producer Examples

using System;
using Confluent.Kafka;

class Program
{
    public static void Main(string[] args)
    {
        var conf = new ProducerConfig { BootstrapServers = "localhost:9092" };

        Action<DeliveryReport<Null, string>> handler = r => 
            Console.WriteLine(!r.Error.IsError
                ? $"Delivered message to {r.TopicPartitionOffset}"
                : $"Delivery Error: {r.Error.Reason}");

        using (var p = new ProducerBuilder<Null, string>(conf).Build())
        {
            for (int i=0; i<100; ++i)
            {
                p.Produce("my-topic", new Message<Null, string> { Value = i.ToString() }, handler);
            }

            // wait for up to 10 seconds for any inflight messages to be delivered.
            p.Flush(TimeSpan.FromSeconds(10));
        }
    }
}

2.Basic Consumer Example

using System;
using System.Threading;
using Confluent.Kafka;

class Program
{
    public static void Main(string[] args)
    {
        var conf = new ConsumerConfig
        { 
            GroupId = "test-consumer-group",
            BootstrapServers = "localhost:9092",
            // Note: The AutoOffsetReset property determines the start offset in the event
            // there are not yet any committed offsets for the consumer group for the
            // topic/partitions of interest. By default, offsets are committed
            // automatically, so in this example, consumption will only start from the
            // earliest message in the topic 'my-topic' the first time you run the program.
            AutoOffsetReset = AutoOffsetReset.Earliest
        };

        using (var c = new ConsumerBuilder<Ignore, string>(conf).Build())
        {
            c.Subscribe("my-topic");

            //c.Committed(new TimeSpan(1000000 * 30));   
            //var lstOffset = c.GetWatermarkOffsets(new TopicPartition(kafkaTopic, 0));  获取缓存中的topic的最大最小偏移

             QueryWatermarkOffsets();//查询topic的最大最少offset，一般获取用这个方法。
            //c.Assign(new TopicPartitionOffset(kafkaTopic, 0, lOffset));  设置从offset开始获取

            CancellationTokenSource cts = new CancellationTokenSource();
            Console.CancelKeyPress += (_, e) => {
                e.Cancel = true; // prevent the process from terminating.
                cts.Cancel();
            };

            try
            {
                while (true)
                {
                    try
                    {
                        var cr = c.Consume(cts.Token);
                        Console.WriteLine($"Consumed message '{cr.Value}' at: '{cr.TopicPartitionOffset}'.");
                    }
                    catch (ConsumeException e)
                    {
                        Console.WriteLine($"Error occured: {e.Error.Reason}");
                    }
                }
            }
            catch (OperationCanceledException)
            {
                // Ensure the consumer leaves the group cleanly and final offsets are committed.
                c.Close();
            }
        }
    }
}

3.另外，制作docker容器时报错：

docker exec -it 029e6df30836 /bin/bash exec: “/bin/bash”: stat /bin/bash: no such file or directory

我们一般可能会在容器启动后进入容器，常用的是docker attach 镜像id，但是启动镜像的时候如果没有带 参数 -it的话，attach进去后可能是日志界面，并不能执行命令。所以我们会用docker exec -it 镜像id /bin/bash/

平常的容器一般都可以执行/bin/bash，很是后缀为-alpine的镜像容器没有，改成 docker exec -it 镜像id sh 就好了。