add request clone recipe for clone instance

This new recipe allow to request an instance with a first software type, which is
called clone instance. Then as soon the instance is ready (connection parameter is
published) then request method will now request the instance normally.

It's used to install clone stack in a partition, the clone stack will sync data
then when all done publish a paramter to say that the instance can be requested
with the real software type.

setup.py

@@ -166,6 +166,7 @@ setup(name=name,
           'readline = slapos.recipe.readline:Recipe',
           'redis.server = slapos.recipe.redis:Recipe',
           'request = slapos.recipe.request:Recipe',
+          'request.clone = slapos.recipe.request:RequestClone',
           'request.serialised = slapos.recipe.request:Serialised',
           'request.edge = slapos.recipe.request:RequestEdge',
           'requestoptional = slapos.recipe.request:RequestOptional',

slapos/recipe/request.py

@@ -32,6 +32,7 @@ from slapos import slap as slapmodule
 from slapos.slap import SoftwareProductCollection
 import slapos.recipe.librecipe.generic as librecipe
 import traceback
+import os
 
 SOFTWARE_PRODUCT_NAMESPACE = "product."
 DEFAULT_SOFTWARE_TYPE = 'RootSoftwareInstance'
@@ -294,3 +295,77 @@ class RequestEdge(Recipe):
 
   update = install
 
+
+class RequestClone(Recipe):
+  """
+  Request one instance, then change software type as soon a return parameter exists.
+  """
+  def __init__(self, buildout, name, options):
+    self.path = os.path.join(buildout['buildout']['directory'],
+                            '.%s-request-clone-%s' % (options['partition-id'],
+                                                    options['name']))
+    # A way to save force clone request and not apply force at every run of buildout
+    self.reclone_check_path = os.path.join(buildout['buildout']['directory'],
+                            '.%s-force-clone-%s' % (options['partition-id'],
+                                                    options['name']))
+    # say if clone instance event if instance already exists
+    check_force = options.get('clone-force-deploy', 'false').lower() \
+                            in librecipe.GenericBaseRecipe.TRUE_VALUES
+
+    if not check_force and os.path.exists(self.reclone_check_path):
+      os.remove(self.reclone_check_path)
+
+    if check_force and not os.path.exists(self.reclone_check_path):
+      with open(self.reclone_check_path, 'w') as f:
+        f.write('Clone on existing instance')
+      if os.path.exists(self.path):
+        os.remove(self.path)
+
+    if os.path.exists(self.path):
+      super(RequestClone, self).__init__(buildout, name, options)
+    else:
+      # Request clone instance untill clone-return parameters are OK
+      software_type = options['software-type']
+      options['software-type'] = options['clone-software-type']
+      for param in options.get('return', '').split():
+          options['connection-%s' % param] = ''
+      options['return'] = options['clone-return']
+      super(RequestClone, self).__init__(buildout, name, options)
+      retun_key = 'connection-%s' % options['clone-return']
+      if self.failed is None and options.has_key(retun_key) and \
+          options[retun_key]:
+        with open(self.path, 'w') as f:
+          f.write('Clone %s is ready.' % options['name'])
+          # Raise, next run should be OK
+          raise Exception("Instance clone %s is ready and should be requested "\
+                  "with software type '%s'" % (options['name'], software_type))
+
+  def install(self):
+    if os.path.exists(self.path):
+      return super(RequestClone, self).install()
+    else:
+      if self._raise_request_exception_formatted:
+        self.logger.warning('Clone request failed.')
+        if not isinstance(self._raise_request_exception, slapmodule.NotFoundError):
+          # full traceback for optional 'not found' is too verbose and confusing
+          self.logger.debug(self._raise_request_exception_formatted)
+      elif self.failed is not None:
+        # Check instance status to know if instance has been deployed
+        try:
+          if self.instance._computer_id is not None:
+            status = self.instance.getState()
+          else:
+            status = 'not ready yet'
+        except (slapmodule.NotFoundError, slapmodule.ServerError, slapmodule.ResourceNotReady):
+          status = 'not ready yet'
+        except AttributeError:
+          status = 'unknown'
+        error_message = 'Connection parameter %s not found. '\
+            'Requested instance is currently %s. If this error persists, '\
+            'check status of this instance.' % (self.failed, status)
+        self.logger.warning(error_message)
+      return []
+
+  update = install
+
+