Linux下librdkafka客户端的编译运行

　　librdkafka是一个开源的Kafka客户端C/C++实现，提供了Kafka生产者、消费者接口。

　　由于项目需要，我要将Kafka生产者接口封装起来给别人调用，所以先安装了librdkakfa，然后在demo上进行修改封装一个生产者接口。

[一] 安装librdkafka

　　 首先在github上下载librdkafka源码，解压后进行编译；

　　 cd librdkafka-master

　　 chmod 777 configure lds-gen.py

　　 ./configure

　　 make

　　 make install

　　 在make的时候，如果是64位Linux会报下面这个异常

　　 /bin/ld:librdkafka.lds:1: syntax error in VERSION script

　　 只要Makefile.config里面的WITH_LDS=y这一行注释掉就不会报错了。

[二] 封装librdkafka的生产者接口

#include <ctype.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <syslog.h>
#include <time.h>
#include <sys/time.h>

#include "librdkafka/rdkafka.h"  /* for Kafka driver */

static int run = 1;
static rd_kafka_t *rk;
rd_kafka_topic_t *rkt;
int partition = RD_KAFKA_PARTITION_UA;
rd_kafka_topic_conf_t *topic_conf;

static void stop (int sig) {
    run = 0;
    fclose(stdin); /* abort fgets() */
}

static void sig_usr1 (int sig) {
    rd_kafka_dump(stdout, rk);
}

int initProducer (char *parameters) {
    int argc = 1;
    char **argv;
    char *para;
    char *delim = " ";
    char *brokers = "localhost:9092";
    char *topic = NULL;
    int opt;
    rd_kafka_conf_t *conf;
    char errstr[512];
    char tmp[16];

    char copyParameters[1024];
    strcpy(copyParameters, parameters);
    para = strtok(parameters, delim);
    argc++;
    while((para = strtok(NULL, delim)) != NULL){
        argc++;
    }
    argv = (char**)malloc(argc*sizeof(char*));
    argc = 0;
    argv[argc] = "initProducer";
    para = strtok(copyParameters, delim);
    argc++;
    argv[argc] = para;
    while((para = strtok(NULL, delim)) != NULL){
        argc++;
        argv[argc] = para;
    }
    argc++;
    /* Kafka configuration */
    conf = rd_kafka_conf_new();
    /* Quick termination */
    snprintf(tmp, sizeof(tmp), "%i", SIGIO);
    rd_kafka_conf_set(conf, "internal.termination.signal", tmp, NULL, 0);
    /* Topic configuration */
    topic_conf = rd_kafka_topic_conf_new();
    while ((opt = getopt(argc, argv, "PCLt:p:b:z:qd:o:eX:As:")) != -1) {
        switch (opt) {
        case ‘t‘:
            topic = optarg;
            break;
        case ‘p‘:
            partition = atoi(optarg);
            break;
        case ‘b‘:
            brokers = optarg;
            break;
        default:
            fprintf(stderr, "%% Failed to init producer with error parameters\n");
        }
    }
    if (optind != argc || !topic) {
        exit(1);
    }
    signal(SIGINT, stop);
    signal(SIGUSR1, sig_usr1);
    /* Create Kafka handle */
    if (!(rk = rd_kafka_new(RD_KAFKA_PRODUCER, conf, errstr, sizeof(errstr)))) {
        fprintf(stderr, "%% Failed to create new producer: %s\n", errstr);
        exit(1);
    }
    rd_kafka_set_log_level(rk, LOG_DEBUG);
    /* Add brokers */
    if (rd_kafka_brokers_add(rk, brokers) == 0) {
        fprintf(stderr, "%% No valid brokers specified\n");
        exit(1);
    }
    /* Create topic */
    rkt = rd_kafka_topic_new(rk, topic, topic_conf);
    topic_conf = NULL; /* Now owned by topic */
    return 1;
}

int freeProducer()
{
    /* Destroy topic */
    rd_kafka_topic_destroy(rkt);
    /* Destroy the handle */
    rd_kafka_destroy(rk);
    if (topic_conf)
        rd_kafka_topic_conf_destroy(topic_conf);
    /* Let background threads clean up and terminate cleanly. */
    run = 5;
    while (run-- > 0 && rd_kafka_wait_destroyed(1000) == -1)
        printf("Waiting for librdkafka to decommission\n");
    if (run <= 0)
        rd_kafka_dump(stdout, rk);
    return 1;
}

int main (int argc, char **argv)
{
    char parameter[] = "-t XX-HTTP-KEYWORD-LOG -b 10.10.6.101:9092,10.10.6.102:9092,10.10.6.104:9092";
    char buf[1024];
    initProducer(parameter);
    while (run && fgets(buf, sizeof(buf), stdin)) {
        if(rd_kafka_produce(rkt, partition, RD_KAFKA_MSG_F_COPY, buf, strlen(buf), NULL, 0, NULL) == -1){
            fprintf(stderr, "%% Failed to produce to topic %s partition %i: %s\n", rd_kafka_topic_name(rkt), partition, rd_kafka_err2str(rd_kafka_last_error()));
        }else{
            fprintf(stderr, "%% Sent %zd bytes to topic %s partition %i\n", strlen(buf), rd_kafka_topic_name(rkt), partition);
        }
    }
    freeProducer();
    return 0;
}

[三] 编译运行

　　 编译的时候要加上-lrdkafka -lz -lpthread -lrt这些选项：gcc myProducer.c -o myProducer -lrdkafka -lz -lpthread -lrt

　　 在编译的时候会报error while loading share library librdkafak.so.1，这是因为make的时候将librdkafak.so.1放在了/usr/local/lib下，在Linux的默认共享库路径/lib和/usr/lib下找不到，只要执行下面两句就可以了：

　　 echo "/usr/local/lib" >> /etc/ld.so.conf
　　 ldconfig

　　 运行./myProducer，会不断的从终端读取键入的字符串，然后发送到Kafka，通过Kafka自带的console consumer能够消费查看数据。