kafka restful api功能介绍与使用

• 前述

采用实现kafka restful service时候（），通过http协议数据传输，需要注意的是采用了base64编码（或者称之为加密），如果消息再post之前不采用base64处理将会出现：服务端消息乱码、程序报错等，因此正常的处理流程是：
1.先对待post的消息做utf-8统一处理
2.采用base64编码包处理消息

s='kafka,hi'
ad="hi,kafka,i'm xnchall"
aa=ad.encode()#utf-8统一处理
print(aa)
b64=base64.b64encode(ad.encode())#base64编码包统一处理

• 利用kafka-rest生产消息

post /topics/(string:topic_name)

data={"records":[
{
"key":"a2v5",
"value":"y29uzmx1zw50"
},
{
"value":"a2fma2e=",
"partition":1
},
{
"value":"bg9ncw=="
}
]}
data1={"records":[{"value":"5bck5pws55qe5a6i5oi35oko5aw977ymagkga2fma2esigknbsb4bmnoywxs"}]}
header={"content-type":"application/vnd.kafka.v1+json"}
r=requests.post(url=url,json=data,headers=header)
r=requests.post(url=url,json=data1,headers=header)

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• 向指定分区生产消息：produce messages to one partition of the topic

post /topics/(string:topic_name)/partitions/(int:partition_id)

ad="hi kafka,i'm xnchall"
url11="http://192.168.160.101:8082/topics/test_kfk_lk/partitions/1"

data2={"records":[{"value":(base64.b64encode(ad.encode())).decode()}]}
print(data2)
r2=requests.post(url=url11,json=data2,headers=header)
print(r2)
print(r2.content)

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• 创建或者注册消费实例：create a new consumer instance in the consumer group

post /consumers/(string:group_name)

url3="http://192.168.160.101:8082/consumers/my_group"
data3={
"id":"my_consumer1",
"format":"binary",
"auto.offset.reset":"smallest",
"auto.commit.enable":"false"
}

r3=requests.post(url=url3,json=data3,headers=header)

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• 提交偏移  commit offsets for the consumer

post /consumers/(string:group_name)/instances/(string:instance)/offsets

url4="http://192.168.160.101:8082/consumers/my_group/instances/my_consumer1/offsets"
r4=requests.post(url=url4,headers=header)

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• 消费消息

get /consumers/(string:group_name)/instances/(string:instance)/topics/(string:topic_name)

url_get2="http://192.168.160.101:8082/consumers/my_group/instances/my_consumer1/topics/test_kfk_lk"
rr2=requests.get(url=url_get2,headers=header)#,params={"timeout":3000000}
print(rr2)
print(rr2.content)
print(rr2.text)

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• 删除消费者实例 destroy the consumer instance

delete /consumers/(string:group_name)/instances/(string:instance)

#url_del="http://192.168.160.101:8082/consumers/test_kfk_lk/instances/my_consumer"
#d1=requests.delete(url_del)#删除消费者实例
#print(d1)

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• 获取指定分区、偏移消息： consume messages from one partition of the topic.(api v2)

get /topics/(string:topic_name)/partitions/(int:partition_id)/messages?offset=(int)[&count=(int)]

fetch response v1 only contains message format v0.
fetch response v2 might either contain message format v0 or message format v1.
possible error codes
* offset_out_of_range (1)
* unknown_topic_or_partition (3)
* not_leader_for_partition (6)
* replica_not_available (9)
* unknown (-1)

url_p="http://192.168.160.101:8082/topics/test_kfk/partitions/0/messages"
rst=requests.get(url_p,headers=header,params={"offset":3,"count":2})#,"count":2})
print(rst)
print(len(rst.json()))
if(rst.status_code!=500):
for itr in rst.json():
    print(base64.b64decode(itr['value']).decode())
print(rst.url)#http://192.168.160.101:8082/topics/test_kfk/partitions/0/messages?offset=3&count=2

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• 获取当前订阅的topic列表.(api v2)

post /consumers/(string:group_name)/instances/(string:instance)/subscription

• 获取手工指定的消费者的分区(api v2)

get /consumers/(string:group_name)/instances/(string:instance)/assignments

get /consumers/testgroup/instances/my_consumer/assignments http/1.1
host: proxy-instance.kafkaproxy.example.com
accept: application/vnd.kafka.v2+json
http/1.1 200 ok
content-type: application/vnd.kafka.v2+json
{
  "partitions": [
    {
      "topic": "test",
      "partition": 0
    },
    {
      "topic": "test",
      "partition": 1
    }
]
}

• 覆盖消费者即将消费的消息的偏移量(api v2)

post /consumers/(string:group_name)/instances/(string:instance)/positions

post /consumers/testgroup/instances/my_consumer/positions http/1.1
host: proxy-instance.kafkaproxy.example.com
content-type: application/vnd.kafka.v2+json
{
  "offsets": [
    {
      "topic": "test",
      "partition": 0,
      "offset": 20
    },
    {
      "topic": "test",
      "partition": 1,
      "offset": 30
    }
  ]
}

• 获取给定topic的分区的最后偏移

post /consumers/(string:group_name)/instances/(string:instance)/positions/end

post /consumers/testgroup/instances/my_consumer/positions/end http/1.1
host: proxy-instance.kafkaproxy.example.com
content-type: application/vnd.kafka.v2+json
{
  "partitions": [
    {
      "topic": "test",
      "partition": 0
    },
    {
      "topic": "test",
      "partition": 1
    }
]
}

• 使用分配和订阅api消费topic或者分区数据

get /consumers/(string:group_name)/instances/(string:instance)/records

get /consumers/testgroup/instances/my_consumer/records?timeout=3000&max_bytes=300000 http/1.1
host: proxy-instance.kafkaproxy.example.com
accept: application/vnd.kafka.binary.v2+json
example binary response:
http/1.1 200 ok
content-type: application/vnd.kafka.binary.v2+json
[
  {
    "topic": "test",
    "key": "a2v5",
    "value": "y29uzmx1zw50",
    "partition": 1,
    "offset": 100,
  },
  {
    "topic": "test",
    "key": "a2v5",
    "value": "a2fma2e=",
    "partition": 2,
    "offset": 101,
  }
]