# egg-yanxin-kafkajs

用于`egg.js`的kafka消息队列插件，依赖于`kafkajs`，相关文档详情：[kafkajs](https://www.npmjs.com/package/kafkajs)

## 依赖说明

### 依赖的 egg 版本

enn-egg-kafka 版本 | egg 1.x
--- | ---
1.x | 😁
0.x | ❌

### 依赖的插件

- kafkajs

## 开启插件

```js
// config/plugin.js
exports.ennEggKafka = {
  enable: true,
  package: 'kafkajs',
};
```

## 使用场景

- 对[kafkajs](https://www.npmjs.com/package/kafkajs)模块封装的eggjs插件


## 配置

- 配置 `config/config.default.js`
```js
// 普通配置
config.ennEggKafka = {
    client: {
        clientId: 'my-app',
        brokers: ['1.1.1.1:9092'],
    },
    consumer: {
        groupId: 'group-test',
        fetchLogger: false, // 是否开启消费记录日志
    },
    producer: {
        allowAutoTopicCreation: true,
    },
};


// 阿里云kafka服务的SASL_SSL协议配置，仅作参考
config.ennEggKafka = {
    client: {
        clientId: 'my-app',
        // 可配置多个地址
        brokers: ['1.1.1.1:9093'],
        ssl: {
            rejectUnauthorized: false,
            // 阿里云ca文件
            ca: [path.join(__dirname, './config/ca-cert')],
        },
        sasl: {
            mechanism: 'plain',
            username: 'your username',
            password: 'your password',
        },
    },
    consumer: {
        groupId: 'group-test',
        fetchLogger: false, // 是否开启消费记录日志
    },
    producer: {
        allowAutoTopicCreation: true,
    }
}
```
其中fetchLogger为新增字段，其他配置字段详见 https://kafka.js.org/docs/getting-started
## 使用

```js
// 生产消息
await app.kafka.producer.sendMessage('test_topic', [{ key: 'key2111', value: 'hey hey!1111' }])

// 单条信息消费
await app.kafka.consumer.initSubscribe({ topics: ['test_topic'] });
app.kafka.consumer.run({
    eachMessage: async ({
      topic,
      partition,
      message,
      heartbeat
    }) => {
      const data = {
        partition,
        topic,
        key: message.key.toString(),
        value: message.value.toString(),
        headers: message.headers,
        timestamp: message.timestamp,
        offset: message.offset,
      };
      if (message.extra) {
        data.extra = message.extra.toString();
      }
      console.log(message)
    }
});
  
// 批量消费信息
await app.kafka.consumer.initConsumer({ topic: 'test_topic' }); 
app.kafka.consumer.run({
    eachBatchAutoResolve: true,
    eachBatch: async ({
      batch,
      resolveOffset,
      heartbeat,
      commitOffsetsIfNecessary,
      uncommittedOffsets,
      isRunning,
      isStale,
    }) => {
        const datas = [];
        for (let message of batch.messages) {
            console.log(message)
            const data = {
            topic: batch.topic,
            partition: batch.partition,
            highWatermark: batch.highWatermark,
            message: {
                offset: message.offset,
                key: message.key.toString(),
                value: message.value.toString(),
                headers: message.headers,
            }
            };
            if (message.extra) {
                data.extra = message.extra.toString();
            }
            resolveOffset(message.offset);
            await heartbeat();
        }
    },
})
```

## License

[MIT](LICENSE)