Interpret scale=0 as a scaler without slaves yet

Instead of 'not a scaler'.

lib/osvcd_mon.py

@@ -592,7 +592,7 @@ def service_orchestrator_auto(self, svc, smon, status):
                 #self.log.info("service %s orchestrator out (hard affinity with %s)",
                 #              svc.svcname, ','.join(intersection))
                 return
-        if svc.scale_target and smon.global_expect is None:
+        if svc.scale_target is not None and smon.global_expect is None:
             target_children = set([self.scale_svcname(svc.svcname, idx) for idx in range(svc.scale_target)])
             current_children = set([svcname for svcname in shared.SERVICES \
                                     if re.match("^[0-9]+\."+svc.svcname+"$", svcname)])
@@ -870,16 +870,18 @@ def service_orchestrator_manual(self, svc, smon, status):
                 self.service_start(svc.svcname)
 
     def scaling_worker(self, svc):
-            for idx in range(svc.scale_target):
-                svcname = self.scale_svcname(svc.svcname, idx)
-                if svcname not in shared.SERVICES:
-                    self.service_create_provision_from(svcname, svc)
-            for svcname in shared.SERVICES:
-                if re.match("^[0-9]+\."+svc.svcname+"$", svcname):
-                    idx = int(svcname.split(".")[0])
-                    if idx >= svc.scale_target:
-                        self.set_smon(svcname, global_expect="purged")
-            self.set_smon(svc.svcname, global_expect="unset", status="idle")
+        if svc.scale_target is None:
+            return
+        for idx in range(svc.scale_target):
+            svcname = self.scale_svcname(svc.svcname, idx)
+            if svcname not in shared.SERVICES:
+                self.service_create_provision_from(svcname, svc)
+        for svcname in shared.SERVICES:
+            if re.match("^[0-9]+\."+svc.svcname+"$", svcname):
+                idx = int(svcname.split(".")[0])
+                if idx >= svc.scale_target:
+                    self.set_smon(svcname, global_expect="purged")
+        self.set_smon(svc.svcname, global_expect="unset", status="idle")
 
     def non_leaders_stopped(self, svc):
         for nodename, instance in self.get_service_instances(svc.svcname).items():

lib/svc.py

@@ -464,7 +464,7 @@ def __init__(self, svcname=None, node=None, cf=None):
         # set by the builder
         self.conf = os.path.join(rcEnv.paths.pathetc, svcname+".conf")
         self.comment = ""
-        self.scale_target = 0
+        self.scale_target = None
         self.orchestrate = "ha"
         self.topology = "failover"
         self.placement = "nodes order"
@@ -630,7 +630,7 @@ def constraints(self):
 
     @lazy
     def enslave_children(self):
-        if self.scale_target:
+        if self.scale_target is not None:
             return True
         try:
             return self.conf_get("DEFAULT", "enslave_children")
@@ -4062,9 +4062,9 @@ def scale(self):
         """
         try:
             value = int(self.options.destination_node)
-            assert value > 0
+            assert value >= 0
         except Exception:
-            raise ex.excError("invalid scale target: set '--to <n>' where n>0")
+            raise ex.excError("invalid scale target: set '--to <n>' where n>=0")
         self._set("DEFAULT", "scale", str(value))
 
     def switch(self):

lib/svcBuilder.py

@@ -2059,6 +2059,8 @@ def build(name, minimal=False, svcconf=None, node=None):
 
     try:
         svc.scale_target = svc.conf_get("DEFAULT", "scale")
+        if isinstance(svc.scale_target, int) and svc.scale_target < 0:
+            svc.scale_target = 0
     except ex.OptNotFound as exc:
         svc.scale_target = exc.default
 
@@ -2072,10 +2074,11 @@ def build(name, minimal=False, svcconf=None, node=None):
     except ex.OptNotFound as exc:
         svc.placement = exc.default
 
-    for i in range(svc.scale_target):
-        name = str(i)+"."+svc.svcname
-        if name not in svc.children:
-            svc.children.append(name)
+    if svc.scale_target is not None:
+        for i in range(svc.scale_target):
+            name = str(i)+"."+svc.svcname
+            if name not in svc.children:
+                svc.children.append(name)
 
     try:
         svc.orchestrate = svc.conf_get("DEFAULT", "orchestrate")
@@ -2172,7 +2175,7 @@ def build(name, minimal=False, svcconf=None, node=None):
     if minimal:
         svc.options.minimal = True
         return svc
-    if svc.scale_target:
+    if svc.scale_target is not None:
         return svc
 
     svc.options.minimal = False

lib/svcdict.py

@@ -840,8 +840,7 @@ def __init__(self):
                   at=True,
                   order=15,
                   convert="integer",
-                  default=0,
-                  text="If set to more than 0, create and provision <scale> enslaved child services named <n>.<svcname>."
+                  text="If set, create and provision <scale> enslaved child services named <n>.<svcname>."
                 )
 
 class KeywordOrchestrate(Keyword):