oracle: add 'OracleStorageAPIClient'

This client will be used to upload images to Oracle Compute Cloud,
through the Oracle Storage Cloud API.

bootstrapvz/providers/oracle/apiclient.py

@@ -0,0 +1,130 @@
+import hashlib
+import logging
+import os
+import requests
+
+
+class OracleStorageAPIClient:
+	MEGABYTE = 1024**2
+
+	def __init__(self, username, password, identity_domain, container):
+		self.username = username
+		self.password = password
+		self.identity_domain = identity_domain
+		self.container = container
+		self.base_url = 'https://' + identity_domain + '.storage.oraclecloud.com'
+		self.log = logging.getLogger(__name__)
+
+	def _fail(self, error):
+		raise RuntimeError('Oracle Storage Cloud API - ' + error)
+
+	@property
+	def auth_token(self):
+		headers = {
+		    'X-Storage-User': 'Storage-{id_domain}:{user}'.format(
+		        id_domain=self.identity_domain,
+		        user=self.username,
+		    ),
+		    'X-Storage-Pass': self.password,
+		}
+		url = self.base_url + '/auth/v1.0'
+		response = requests.get(url, headers=headers)
+		if response.status_code == 200:
+			return response.headers.get('x-auth-token')
+		else:
+			self._fail(response.text)
+
+	@property
+	def chunk_size(self):
+		file_size = os.path.getsize(self.file_path)
+		if file_size > (300 * self.MEGABYTE):
+			chunk_size = 100 * self.MEGABYTE
+		else:
+			chunk_size = 50 * self.MEGABYTE
+		return chunk_size
+
+	def compare_files(self):
+		uploaded_file_md5 = hashlib.md5()
+		downloaded_file_md5 = hashlib.md5()
+		files = [self.file_path, self.target_file_path]
+		hashes = [uploaded_file_md5, downloaded_file_md5]
+		for f, h in zip(files, hashes):
+			with open(f, 'rb') as current_file:
+				while True:
+					data = current_file.read(self.MEGABYTE)
+					if not data:
+						break
+					h.update(data)
+		if uploaded_file_md5.hexdigest() != downloaded_file_md5.hexdigest():
+			self.log.error('File hashes mismatch')
+		else:
+			self.log.info('Both files have the same hash')
+
+	def create_manifest(self):
+		headers = {
+		    'X-Auth-Token': self.auth_token,
+		    'X-Object-Manifest': '{container}/{object_name}-'.format(
+		        container=self.container,
+		        object_name=self.file_name,
+		    ),
+		    'Content-Length': '0',
+		}
+		url = self.object_url
+		self.log.info('Creating remote manifest to join chunks')
+		response = requests.put(url, headers=headers)
+		if response.status_code != 201:
+			self._fail(response.text)
+
+	def download_file(self):
+		headers = {
+		    'X-Auth-Token': self.auth_token,
+		}
+		url = self.object_url
+		response = requests.get(url, headers=headers, stream=True)
+		if response.status_code != 200:
+			self._fail(response.text)
+		with open(self.target_file_path, 'wb') as f:
+			for chunk in response.iter_content(chunk_size=self.MEGABYTE):
+				if chunk:
+					f.write(chunk)
+
+	@property
+	def file_name(self):
+		return os.path.basename(self.file_path)
+
+	@property
+	def object_url(self):
+		url = '{base}/v1/Storage-{id_domain}/{container}/{object_name}'.format(
+		    base=self.base_url,
+		    id_domain=self.identity_domain,
+		    container=self.container,
+		    object_name=self.file_name,
+		)
+		return url
+
+	def upload_file(self):
+		f = open(self.file_path, 'rb')
+		n = 1
+		while True:
+			chunk = f.read(self.chunk_size)
+			if not chunk:
+				break
+			chunk_name = '{name}-{number}'.format(
+			    name=self.file_name,
+			    number='{0:04d}'.format(n),
+			)
+			headers = {
+			    'X-Auth-Token': self.auth_token,
+			}
+			url = '{base}/v1/Storage-{id_domain}/{container}/{object_chunk_name}'.format(
+			    base=self.base_url,
+			    id_domain=self.identity_domain,
+			    container=self.container,
+			    object_chunk_name=chunk_name,
+			)
+			self.log.info('Uploading chunk ' + chunk_name)
+			response = requests.put(url, data=chunk, headers=headers)
+			if response.status_code != 201:
+				self._fail(response.text)
+			n += 1
+		self.create_manifest()