vsi_proxy.py

"""
This is a local proxy to intercept GDAL vsigs request (when storing data
on google cloud storage) and inject error codes to exercise the logging
codepath.

Usage:
    $ python vsi_proxy.py
    $ CPL_GS_ENDPOINT=http://localhost:9999/ gdal_translate -srcwin 5000 5000 2000 2000 /vsigs/mybucketfile.tif out.tit

"""
from http.server import BaseHTTPRequestHandler
from http.server import HTTPServer
import requests
from urllib.error import HTTPError
import urllib.request
import shutil
import logging
import sys
import random
logging.basicConfig(stream=sys.stdout, level=logging.INFO)


ENDPOINT = 'https://storage.googleapis.com'


class ProxyHandler(BaseHTTPRequestHandler):
    def do_GET(self):  # noqa
        headers = dict(self.headers)
        headers['Host'] = 'storage.googleapis.com'
        # Fail some range requests
        if 'Range' in headers and random.random() < 0.5:
            print('\nFAILING range request\n')
            self.send_response(403)
            self.end_headers()
            self.wfile.write('Unauthorized'.encode('utf-8'))
        else:
            print('path=%s, headers=%s' % (self.path, headers))
            resp = requests.request('GET', ENDPOINT + self.path, headers=headers)
            self.send_response(resp.status_code)
            #print('response code=%s , headers: ' % resp.status_code)
            for k, v in resp.headers.items():
                #print(k, v)
                self.send_header(k, v)
            self.end_headers()
            self.wfile.write(resp.content)


mock_server = HTTPServer(('localhost', 9999), ProxyHandler)
mock_server.serve_forever()