REST Client in Python

Introduction

A guide to using the GemFire REST API from a Python client. This example demonstrates how to establish a connection, authenticate your session, and perform basic CRUD operations using standard Python libraries. It is designed for developers who want to integrate GemFire into their existing Python workflows efficiently.

GemFire REST Client in Python

At the end of this article is an example Python script that accesses a GemFire client using the REST API.
To run this example, GemFire must first be installed and a cluster must be started with the REST API enabled.
The step-by-step instructions:

Install GemFire according the instructions found at Getting Started with VMware GemFire.

With the gemfire bin directory in your command PATH, start the GemFire shell:

> gfsh

Start a locator:

gfsh> start locator --name=locator1

Start a server with the REST API enabled. The example code expects the http service to be running on port 8080:

gfsh> start server --name=server1 --start-rest-api=true --http-service-port=8080 --http-service-bind-address=localhost --server-port=40405

Connect to the cluster in gfsh:

gfsh> connect

Create a region with name “demoRegion” (as expected by the example code):

gfsh> create region --name=demoRegion --type=REPLICATE

Exit gfsh

gfsh> exit

Using python3, run the python example. The code is available Here is the code:

#!/usr/bin/env python3

# This assumes you have created a region called "demoRegion".

import json
import uuid
import requests

REGION = "demoRegion"
BASE_URI = "http://localhost:8080/gemfire-api/v1"

headers = {'content-type': 'application/json'}

person = {'type': 'Person',
          'firstName': 'John',
          'middleName': 'Q',
          'lastName': 'Public',
          'birthDate': '1 Jan 1900'}


def resource_uri(res=None, region=REGION):
    if res:
        return "%s/%s/%s" % (BASE_URI, region, res)
    return "%s/%s" % (BASE_URI, region)


print("[*] First, we'll empty out our demo region - DELETE %s" %
      requests.delete(resource_uri()))

r = requests.delete(resource_uri())
r.raise_for_status()

print("[*] Now, we'll create 5 demo objects")

keys = []

for i in range(1, 6):
    key = uuid.uuid1()

    keys.append(key)
    person['uuid'] = str(key)

    print("\t Creating object with key: POST %s" % key)
    r = requests.post(resource_uri(), json=person,
                      params={'key': key},
                      headers=headers)
    r.raise_for_status()

print("[*] List our keys - GET %s" % resource_uri("keys"))

r = requests.get(resource_uri("keys"))
print(r.text)

print("[*] Here's all our data - GET %s" % resource_uri())

r = requests.get(resource_uri())
print(r.text)

print("[*] Now each key one by one")

for key in keys:
    print("Fetching key - GET %s" % resource_uri(res=key))
    r = requests.get(resource_uri(res=key))
    print(r.text)

print("[*] Now grab one, change the first name to 'Jane' and save it")

print("  GET - %s" % resource_uri(res=keys[0]))
r = requests.get(resource_uri(res=keys[0]))
p = json.loads(r.text)
p['firstName'] = 'Jane'
print("  PUT - %s" % resource_uri(res=keys[0]))
r = requests.put(resource_uri(res=keys[0]), json=p,
                 headers=headers)

print("  GET - %s" % resource_uri(res=keys[0]))
r = requests.get(resource_uri(res=keys[0]))
print(r.text)