Flume之自定义Intercept

Flume 有各种自带的拦截器，比如：TimestampInterceptor、HostInterceptor、RegexExtractorInterceptor 等，通过使用不同的拦截器，实现不同的功能。但是以上的这些拦截器，不能改变原有日志数据的内容或者对日志信息添加一定的处理逻辑，通过自定义Interceptor来实现对字段的控制

主要内容：

• 1.需求
• 2.编码实现

相关文章：
1.CentOS7安装Nginx
2.Flume之采集Nginx的日志
3.Flume之自定义Intercept

1.需求

原始Nginx日志

139.199.86.244|2018-08-17T05:35:45+08:00|104.194.100.87|GET /mysqladmin/index.php HTTP/1.1|0.003|404|76|104.128.100.46:8085|0.002|404|-|Mozilla/5.0

采集后

server1|nginx|access.log|139.199.86.244|2018-08-17T05:35:45+08:00|104.194.100.87|GET /mysqladmin/index.php HTTP/1.1|0.003|404|76|104.128.100.46:8085|0.002|404|-|Mozilla/5.0

其中server1|nginx|access.log是自定义添加的信息（主机、应用名、监听的文件）

2.编码实现

2.1.定义配置常量

public static class Constants {
    public static final String HOST = "host";
    public static final String HOST_DEFAULT = "UNKNOW";
    public static final String APP = "app";
    public static final String APP_DEFAULT = "UNKNOW";
    public static final String FILE_NAME = "fileName";
    public static final String FILE_NAME_DEFAULT = "UNKNOW";
    public static final String DELIMITER = "delimiter";
    public static final String DELIMITER_DEFAULT = "|";
}

其中host=主机名（默认UNKNOW），app=应用名（默认UNKNOW），fileName=文件名（默认UNKNOW），delimiter=分隔符（默认 "|"）

2.2.定义MyIntercepter实现Intercepter接口

public class MyIntercepter implements Interceptor {
    private String host;
    private String app;
    private String fileName;
    private String delimiter;

    public MyIntercepter(String host, String app, String fileName, String delimiter) {
        this.host = host;
        this.app = app;
        this.fileName = fileName;
        this.delimiter = delimiter;
    }

    public void initialize() {

    }

    public Event intercept(Event event) {
        if (event == null) {
            return null;
        }
        try {
            String line = new String(event.getBody(), Charsets.UTF_8);
            StringBuilder sb = new StringBuilder();
            sb.append(host);
            sb.append(delimiter);
            sb.append(app);
            sb.append(delimiter);
            sb.append(fileName);
            sb.append(delimiter);
            sb.append(line);
            event.setBody(sb.toString().getBytes(Charsets.UTF_8));
            return event;
        } catch (Exception e) {
            return event;
        }
    }

    public List<Event> intercept(List<Event> list) {
        List<Event> out = new ArrayList<Event>(list.size());
        for (Event event : list) {
            Event outEvent = intercept(event);
            if (outEvent != null) {
                out.add(outEvent);
            }
        }
        return out;
    }

    public void close() {

    }
}

重写intercept(Event event)和intercept(List<Event> list)方法

2.3.MyIntercepter内部定义Builder

/**
 * 获取配置文件
 */
public static class Builder implements Interceptor.Builder {

  private String host;
  private String app;
  private String fileName;
  private String delimiter;

  /*
   * @see org.apache.flume.conf.Configurable#configure(org.apache.flume.Context)
   */
  public void configure(Context context) {
    host = context.getString(Constants.HOST, Constants.HOST_DEFAULT);
    app = context.getString(Constants.APP, Constants.APP_DEFAULT);
    fileName = context.getString(Constants.FILE_NAME, Constants.FILE_NAME_DEFAULT);
    delimiter = context.getString(Constants.DELIMITER, Constants.DELIMITER_DEFAULT);
  }

  /*
   * @see org.apache.flume.interceptor.Interceptor.Builder#build()
   */
  public Interceptor build() {
    return new MyIntercepter(host, app, fileName, delimiter);
  }
}

接口中定义了一个内部接口 Builder，在 configure 方法中，进行一些参数
配置。并给出，在 flume 的 conf 中没配置一些参数时，给出其默认值。通
过其 builder 方法，返回一个 MyIntercepter对象。

完整代码如下：

package me.jinkun.flume;

import com.google.common.base.Charsets;
import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.interceptor.Interceptor;

import java.util.ArrayList;
import java.util.List;

/**
 * 自定义插件用于指定host和app
 * a1.sources.r1.interceptors = i1
 * a1.sources.r1.interceptors.i1.type = me.jinkun.flume.MyIntercepter$Builder
 * a1.sources.r1.interceptors.i1.host=server1
 * a1.sources.r1.interceptors.i1.app=nginx
 * a1.sources.r1.interceptors.i1.fileName=access.log
 * a1.sources.r1.interceptors.i1.delimiter=|
 *
 */
public class MyIntercepter implements Interceptor {
    private String host;
    private String app;
    private String fileName;
    private String delimiter;

    public MyIntercepter(String host, String app, String fileName, String delimiter) {
        this.host = host;
        this.app = app;
        this.fileName = fileName;
        this.delimiter = delimiter;
    }

    public void initialize() {

    }

    public Event intercept(Event event) {
        if (event == null) {
            return null;
        }
        try {
            String line = new String(event.getBody(), Charsets.UTF_8);
            StringBuilder sb = new StringBuilder();
            sb.append(host);
            sb.append(delimiter);
            sb.append(app);
            sb.append(delimiter);
            sb.append(fileName);
            sb.append(delimiter);
            sb.append(line);
            event.setBody(sb.toString().getBytes(Charsets.UTF_8));
            return event;
        } catch (Exception e) {
            return event;
        }
    }

    public List<Event> intercept(List<Event> list) {
        List<Event> out = new ArrayList<Event>(list.size());
        for (Event event : list) {
            Event outEvent = intercept(event);
            if (outEvent != null) {
                out.add(outEvent);
            }
        }
        return out;
    }

    public void close() {

    }

    /**
     *
     */
    public static class Constants {
        public static final String HOST = "host";
        public static final String HOST_DEFAULT = "UNKNOW";
        public static final String APP = "app";
        public static final String APP_DEFAULT = "UNKNOW";
        public static final String FILE_NAME = "fileName";
        public static final String FILE_NAME_DEFAULT = "UNKNOW";
        public static final String DELIMITER = "delimiter";
        public static final String DELIMITER_DEFAULT = "|";
    }

    /**
     * 获取配置文件
     */
    public static class Builder implements Interceptor.Builder {

        private String host;
        private String app;
        private String fileName;
        private String delimiter;

        /*
         * @see org.apache.flume.conf.Configurable#configure(org.apache.flume.Context)
         */
        public void configure(Context context) {
            host = context.getString(Constants.HOST, Constants.HOST_DEFAULT);
            app = context.getString(Constants.APP, Constants.APP_DEFAULT);
            fileName = context.getString(Constants.FILE_NAME, Constants.FILE_NAME_DEFAULT);
            delimiter = context.getString(Constants.DELIMITER, Constants.DELIMITER_DEFAULT);
        }

        /*
         * @see org.apache.flume.interceptor.Interceptor.Builder#build()
         */
        public Interceptor build() {
            return new MyIntercepter(host, app, fileName, delimiter);
        }
    }
}

2.4.打成jar文件

将编写好的代码打成jar文件，并上传到flume/lib目录下

jar文件
flume/lib

3.使用示例

# Name the components on this agent
a1.sources = r1
a1.sinks = k1
a1.channels = c1

# Describe/configure the source
a1.sources.r1.type = exec
a1.sources.r1.command = tail -F /opt/soft/nginx-1.14.0/logs/access.log

#自定义拦截器
a1.sources.r1.interceptors = i1
a1.sources.r1.interceptors.i1.type = me.jinkun.flume.MyIntercepter$Builder
a1.sources.r1.interceptors.i1.host=server1
a1.sources.r1.interceptors.i1.app=nginx
a1.sources.r1.interceptors.i1.fileName=access.log

# Describe the sink
a1.sinks.k1.type = avro
a1.sinks.k1.hostname = 0.0.0.0
a1.sinks.k1.port = 41414

# Use a channel which buffers events in memory
a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000
a1.channels.c1.transactionCapacity = 100