[pulsar-io] Add a Pulsar IO connector for InfluxDB sink

[murong00]

Motivation

Provides a builtin InfluxDB sink Connector, in order to persist pulsar messages to a InfluxDB database.

Modifications

Add a InfluxDB Sink and some unit tests.

Verifying this change

This change can be verified as follows:

• deploy the InfluxDB Sink connector with configuration file containing the following fields:

configs:
    influxdbUrl: "http://localhost:8086"
    database: "test_db"
    consistencyLevel: "ONE"
    logLevel: "NONE"
    retentionPolicy: "autogen"
    gzipEnable: "false"
    batchTimeMs: "1000"
    batchSize: "100"

• deploy an InfluxDB instance and create the above elements
• send messages in the topic with specified schema declared when deploying the connector
• use influx CLI to query messages in the specified database

[merlimat]

should have sensitive=true

[murong00]

Done.

[merlimat]

should have sensitive=true

[murong00]

Done.

[ambition119]

a little suggestion：

if (!databases.contains(influxDatabase)) {
    if(influxDBSinkConfig.isCreateDatabase()) {
         influxDB.createDatabase(influxDatabase);
      }
      else {
        throw new IllegalArgumentException("This " + influxDBSinkConfig.getDatabase() + " database does not exist!");
      }
}

[murong00]

@ambition119 Thanks for the reviewing, it's not necessary to do this as field database is required and has been checked in method validate().

[murong00]

run java8 tests

[merlimat]

👍