1 files changed, 63 insertions, 0 deletions
diff --git a/Monitoring/MonitoringService/Driver/REST.py b/Monitoring/MonitoringService/Driver/REST.py
new file mode 100644
index 0000000..bf4fc2f
--- /dev/null
+++ b/Monitoring/MonitoringService/Driver/REST.py
@@ -0,0 +1,63 @@
+'''
+Created on Feb 4, 2013
+
+@author: steger, jozsef
+@organization: ELTE
+@contact: steger@complex.elte.hu
+'''
+
+from Driver import Driver
+from Credential.credentialtypes import UsernamePassword
+from httplib2 import Http
+
+class RESTDriver(Driver):
+    '''
+    @summary: implements REST driver to fetch using http GET
+    @cvar timeout: timeout of connection
+    @type timeout: float
+    @cvar cache: a cache directory
+    @type cache: str
+    @ivar url: a default document locator to be reused
+    @type url: str
+    @ivar proxy: an interface to the http server
+    @type proxy: httplib2.Http
+    '''
+    timeout = 10
+    cache = "/tmp/.cache"
+    
+    def __init__(self, url, credential = None, validate_ssl = False):
+        '''
+        @summary: initializes a proxy to the http service and saves a default document locator
+        @param url: the default document locator
+        @type url: str
+        @param credential: an authentication secret
+        @type credential: L{Credential} or None
+        @param validate_ssl: whether to apply strick certificate validation, default is False
+        @type validate_ssl: bool 
+        '''
+        self.url = url
+        self.proxy = Http(cache = self.cache, timeout = self.timeout)
+        self.proxy.disable_ssl_certificate_validation = not validate_ssl
+        if isinstance(credential, UsernamePassword):
+            # use password authentication
+            self.proxy.add_credentials(credential.username, credential.password)
+
+    def fetch(self, url = None):
+        '''
+        @summary: retrieve the document
+        @param url: the document locator, if not present the default is used
+        @type url: str or None
+        @return: the remote document
+        @rtype: str or None
+        @note: if the remote content cached is not changed, None is returned
+        '''
+        if url is None:
+            url = self.url
+        status, response = self.proxy.request(uri = url, method = "GET")
+        if status.status == 200:
+            return response
+        if status.status == 304:
+            self.logger.warning("remote content @ %s was not changed" % url)
+            return None
+        self.logger.error("%s -- retrieving @%s failed: %s" % (status, url, response))
+        return None