Build a quick storage library for accessing Windows Azure.

This will be used by the Python cleaner, but that is not yet hooked up.

diff --git a/cleaner/azure.py b/cleaner/azure.py
new file mode 100644 (file)
index 0000000..d976e0f
--- /dev/null
+++ b/cleaner/azure.py
@@ -0,0 +1,163 @@
+"""A simple Python library for accessing the Windows Azure blob service."""
+
+import base64, hashlib, hmac, httplib, os, time, urllib
+import xml.dom.minidom
+
+# The version of the Azure API we implement; sent in the x-ms-version header.
+API_VERSION = '2009-09-19'
+
+def uri_decode(s):
+    return urllib.unquote_plus(s)
+
+def uri_encode(s):
+    return urllib.quote_plus(s)
+
+def xmlGetText(nodelist):
+    text = []
+    def walk(nodes):
+        for node in nodes:
+            if node.nodeType == node.TEXT_NODE:
+                text.append(node.data)
+            else:
+                walk(node.childNodes)
+    walk(nodelist)
+    return ''.join(text)
+
+def xmlParse(s):
+    return xml.dom.minidom.parseString(s)
+
+def buildQueryString(uri, params={}):
+    for (k, v) in params.items():
+        if v is None: continue
+        kv = '%s=%s' % (uri_encode(k), uri_encode(v))
+        if '?' not in uri:
+            uri += '?' + kv
+        else:
+            uri += '&' + kv
+    return uri
+
+def add_auth_headers(headers, method, path, account, key):
+    header_order = ['Content-Encoding', 'Content-Language', 'Content-Length',
+                    'Content-MD5', 'Content-Type', 'Date', 'If-Modified-Since',
+                    'If-Match', 'If-None-Match', 'If-Unmodified-Since',
+                    'Range']
+
+    if not headers.has_key('Date'):
+        headers['Date'] = time.strftime("%a, %d %b %Y %H:%M:%S GMT",
+                                        time.gmtime())
+    if not headers.has_key('x-ms-version'):
+        headers['x-ms-version'] = API_VERSION
+
+    StringToSign = method + "\n"
+    for h in header_order:
+        if h in headers:
+            StringToSign += headers[h] + "\n"
+        else:
+            StringToSign += "\n"
+
+    # Add Canonicalized Headers
+    canonized = []
+    for (k, v) in headers.items():
+        k = k.lower()
+        if k.startswith('x-ms-'):
+            canonized.append((k, v))
+    canonized.sort()
+    for (k, v) in canonized:
+        StringToSign += "%s:%s\n" % (k, v)
+
+    resource = "/" + account
+    if '?' not in path:
+        resource += path
+    else:
+        (path, params) = path.split('?', 1)
+        params = [p.split('=') for p in params.split("&")]
+        params = dict((k.lower(), uri_decode(v)) for (k, v) in params)
+        resource += path
+        for k in sorted(params):
+            resource += "\n%s:%s" % (k, params[k])
+    StringToSign += resource
+
+    h = hmac.new(key, digestmod=hashlib.sha256)
+    h.update(StringToSign)
+
+    signature = base64.b64encode(h.digest())
+    headers['Authorization'] = "SharedKey %s:%s" % (account, signature)
+
+class AzureError(RuntimeError):
+    def __init__(self, response):
+        self.response = response
+        self.details = response.read()
+
+class AzureConnection:
+    def __init__(self, account=None, key=None):
+        if account is None:
+            account = os.environ['AZURE_ACCOUNT_NAME'] 
+        self.account = account
+        self.host = account + ".blob.core.windows.net"
+        #self.conn = httplib.HTTPConnection(self.host)
+
+        if key is None:
+            key = os.environ['AZURE_SECRET_KEY']
+        self.key = base64.b64decode(key)
+
+    def _make_request(self, path, method='GET', body="", headers={}):
+        headers = headers.copy()
+        headers['Content-Length'] = str(len(body))
+        if len(body) > 0:
+            headers['Content-MD5'] \
+                = base64.b64encode(hashlib.md5(body).digest())
+        add_auth_headers(headers, method, path, self.account, self.key)
+
+        conn = httplib.HTTPConnection(self.host)
+        conn.request(method, path, body, headers)
+        response = conn.getresponse()
+        if response.status // 100 != 2:
+            raise AzureError(response)
+        return response
+        #print "Response:", response.status
+        #print "Headers:", response.getheaders()
+        #body = response.read()
+
+    def list(self, container, prefix=''):
+        marker = None
+        while True:
+            path = '/' + container + '?restype=container&comp=list'
+            path = buildQueryString(path, {'prefix': prefix, 'marker': marker})
+            r = self._make_request(path)
+            xml = xmlParse(r.read())
+
+            blobs = xml.getElementsByTagName('Blob')
+            for b in blobs:
+                yield xmlGetText(b.getElementsByTagName('Name'))
+
+            marker = xmlGetText(xml.getElementsByTagName('NextMarker'))
+            if marker == "":
+                return
+
+    def get(self, container, key):
+        path = "/%s/%s" % (container, key)
+        r = self._make_request(path)
+        return r.read()
+
+    def put(self, container, key, value):
+        path = "/%s/%s" % (container, key)
+        r = self._make_request(path, method='PUT', body=value,
+                               headers={'x-ms-blob-type': 'BlockBlob'})
+
+    def delete(self, container, key):
+        path = "/%s/%s" % (container, key)
+        r = self._make_request(path, method='DELETE')
+
+if __name__ == '__main__':
+    container = 'benchmark'
+    conn = AzureConnection()
+
+    print "Container contents:"
+    for k in conn.list(container):
+        print k
+
+    conn.put(container, "testkey", "A" * 40)
+    print "Fetch result:", conn.get(container, "testkey")
+
+    for k in list(iter(conn.list(container))):
+        conn.delete(container, k)