Add query example for pyarrow.flight FlightClient

Provide a v3 query example using pyarrow.flight FlightClient. Add pyarrow.flight to Flight SQL clients reference.

Some sample code that doesn't yet work. Token authentication still apparently requires middleware or inserting the auth header in a way that isn't clear in the docs or code.

from pyarrow.flight import FlightClient, Ticket, \
  FlightCallOptions, Action, \
  ClientMiddleware
import json
import pandas as pd
import os

DATABASE_NAME = os.getenv('CLOUD_SERVERLESS_BUCKET_NAME')
DATABASE_TOKEN = os.getenv('CLOUD_SERVERLESS_READ_WRITE_TOKEN')
INFLUXDB_HOST=os.getenv('CLOUD_SERVERLESS_HOST')

# influxql = "SELECT MEAN(elapsed) FROM home WHERE time >= '2023-04-07 19:35:19.314571143' AND time <= '2023-04-07 21:51:29.638717686' GROUP BY time(10m)"

client = FlightClient(f"grpc+tls://{INFLUXDB_HOST}:443")
token_bytes = bytes(f"Bearer {DATABASE_TOKEN}".encode('utf-8'))
token_pair = (b'authorization', token_bytes)
database = (b'database', bytes(DATABASE_NAME.encode('utf-8')))
options = FlightCallOptions(headers=[token_pair, database])

# do_action = client.do_action(action, options)

# client.authenticate(options)

def test_sql_query():

  sql = "SELECT * FROM home where room like 'telegraf%'"

  ticket_data = {
    "sql_query": sql,
    "query_type": "sql"
  }

  ticket_bytes = json.dumps(ticket_data)
  ticket = Ticket(ticket_bytes)
  reader = client.do_get(ticket=ticket, options=options)
  arrow_table = reader.read_all()
  # data_frame = arrow_table.to_pandas()
  # print(data_frame.to_markdown())

test_sql_query()

Relevant URLs

Provide relevant URLs (issues, community threads, existing doc pages, etc.)

influxdata / docs-v2

Add query example for pyarrow.flight FlightClient #4926

Relevant URLs