deploy: Fix context issues in fabfile

Ensure that the context that each component is setup with, is
the correct one and does not include stale entries.

Use fabric's execute() method with hosts argument the proper
target nodes derived from current context. Introduce three
new decorators for this purpose:

 - with_ctx gets the current context
 - with_node updates the context's node with env.host
 - with_cluster updates the context's cluster with env.host
Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>

snf-deploy/snfdeploy/context.py

@@ -46,29 +46,29 @@ class Context(object):
 
     def update(self, node=None, role=None, cluster=None, setup=None):
         if node:
-            self.node = node
+            context.node = self.node = node
         if role:
-            self.role = role
+            context.role = self.role = role
         if cluster:
-            self.cluster = cluster
+            context.cluster = self.cluster = cluster
         if setup:
-            self.setup = setup
+            context.setup = self.setup = setup
         self.update_info()
 
     def update_info(self):
-        self.ns = self.get(constants.NS)
-        self.nfs = self.get(constants.NFS)
-        self.mq = self.get(constants.MQ)
-        self.db = self.get(constants.DB)
-        self.astakos = self.get(constants.ASTAKOS)
-        self.cyclades = self.get(constants.CYCLADES)
-        self.pithos = self.get(constants.PITHOS)
-        self.stats = self.get(constants.STATS)
-        self.cms = self.get(constants.CMS)
-        self.router = self.get(constants.ROUTER)
-        self.client = self.get(constants.CLIENT)
-
-    def get(self, role):
+        self.ns = self._get(constants.NS)
+        self.nfs = self._get(constants.NFS)
+        self.mq = self._get(constants.MQ)
+        self.db = self._get(constants.DB)
+        self.astakos = self._get(constants.ASTAKOS)
+        self.cyclades = self._get(constants.CYCLADES)
+        self.pithos = self._get(constants.PITHOS)
+        self.stats = self._get(constants.STATS)
+        self.cms = self._get(constants.CMS)
+        self.router = self._get(constants.ROUTER)
+        self.client = self._get(constants.CLIENT)
+
+    def _get(self, role):
         return config.get_single_node_role_info(self.setup, role)
 
     @property
@@ -101,9 +101,12 @@ class Context(object):
     def nodes(self):
         return list(set(self.masters + self.vmcs))
 
+    def get(self, role):
+        try:
+            return config.get(self.setup, role)
+        except:
+            return config.get(self.cluster, role)
 
-def get(role):
-    return config.get(context.setup, role)
 
 def backup():
     context.node_backup = context.node

snf-deploy/snfdeploy/fabfile.py

@@ -26,41 +26,77 @@ from fabric.api import env, execute, parallel
 from snfdeploy import context
 from snfdeploy import constants
 from snfdeploy import roles
+import copy
+
+
+def with_ctx(fn):
+    def wrapper(*args):
+        ctx = context.Context()
+        return fn(*args, ctx=ctx)
+    return wrapper
+
+
+def with_cluster(fn):
+    def wrapper(old_ctx, *args):
+        ctx = copy.deepcopy(old_ctx)
+        ctx.update(cluster=env.host)
+        return fn(ctx, *args)
+    return wrapper
+
+
+def with_node(fn):
+    def wrapper(old_ctx, *args):
+        ctx = copy.deepcopy(old_ctx)
+        ctx.update(node=env.host)
+        return fn(ctx, *args)
+    return wrapper
 
 
 def setup_env(args):
     env.component = args.component
     env.method = args.method
-    env.ctx = context.Context()
+    env.role = args.role
+
 
+# Helper methods that are invoked via fabric's execute
 
 @parallel
-def setup_vmc():
-    env.ctx.update(node=env.host)
-    VMC = roles.get(constants.VMC, env.ctx)
+@with_node
+def _setup_vmc(ctx):
+    VMC = roles.get(constants.VMC, ctx)
     VMC.setup()
 
 
-def setup_master():
-    env.ctx.update(node=env.host)
-    _setup_role(constants.MASTER)
+@with_node
+def _setup_master(ctx):
+    MASTER = roles.get(constants.MASTER, ctx)
+    MASTER.setup()
+
+
+@with_node
+def _setup_role(ctx, role):
+    ROLE = roles.get(role, ctx)
+    ROLE.setup()
 
 
 @parallel
-def setup_cluster():
-    env.ctx.update(cluster=env.host)
-    execute(setup_master, hosts=env.ctx.masters)
-    execute(setup_vmc, hosts=env.ctx.vmcs)
+@with_cluster
+def _setup_cluster(ctx):
+    execute(_setup_master, ctx, hosts=ctx.masters)
+    execute(_setup_vmc, ctx, hosts=ctx.vmcs)
 
 
-def _setup_role(role):
-    env.ctx.update(node=env.host)
-    ROLE = roles.get(role, env.ctx)
-    ROLE.setup()
+# Helper method that get a context snapshot and
+# invoke fabric's execute with proper host argument
 
+@with_ctx
+def setup_role(role, ctx=None):
+    execute(_setup_role, ctx, role, hosts=ctx.get(role))
 
-def setup_role(role):
-    execute(_setup_role, role, hosts=context.get(role))
+
+@with_ctx
+def setup_cluster(ctx=None):
+    execute(_setup_cluster, ctx, hosts=ctx.clusters)
 
 
 def setup_synnefo():
@@ -74,7 +110,7 @@ def setup_synnefo():
     setup_role(constants.CYCLADES)
     setup_role(constants.CMS)
 
-    execute(setup_cluster, hosts=env.ctx.clusters)
+    setup_cluster()
 
     setup_role(constants.STATS)
     setup_role(constants.CLIENT)
@@ -83,27 +119,29 @@ def setup_synnefo():
 def setup_ganeti():
     setup_role(constants.NS)
     setup_role(constants.NFS)
-    execute(setup_cluster, hosts=env.ctx.clusters)
+    setup_cluster()
 
 
-def _setup_qa():
-    env.ctx.update(cluster=env.host)
+@with_cluster
+def _setup_qa(ctx):
     setup_role(constants.NS)
     setup_role(constants.NFS)
     setup_cluster()
     setup_role(constants.DEV)
 
 
-def setup_qa():
-    execute(_setup_qa, hosts=env.ctx.clusters)
+@with_ctx
+def setup_qa(ctx=None):
+    execute(_setup_qa, ctx, hosts=ctx.clusters)
 
 
-def setup():
+@with_ctx
+def setup(ctx=None):
     if env.component:
         target = env.component
     else:
-        target = env.ctx.role
-    C = roles.get(target, env.ctx)
+        target = env.role
+    C = roles.get(target, ctx)
     if env.method:
         fn = getattr(C, env.method)
         fn()