Merge lp:~hazmat/juju-deployer/unit-placement into lp:juju-deployer

[Kapil Thangavelu]

Support for unit placement using deployer configuration. Also improve terminate/reset support with containers, and a fix for --diff output.

[Adam Gandelman (gandelman-a)]

Testing this now, couple of issues so far:

If a service is configured as:

fooservice:
   to: [0]

deployer blows up:

  70, in get_unit_placement
    if ':' in unit_placement:
TypeError: argument of type 'int' is not iterable

Only running that code if unit_placement is a string seems to fix that.

Adding units fails:

2013-10-31 17:34:26 [INFO] deployer.import: Adding 2 more units to nova-compute
Traceback (most recent call last):
  File "/usr/local/bin/juju-deployer", line 9, in <module>
    load_entry_point('juju-deployer==0.2.8', 'console_scripts', 'juju-deployer')()
  File "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/cli.py", line 118, in main
    run()
  File "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/cli.py", line 209, in run
    importer.Importer(env, deployment, options).run()
  File "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/action/importer.py", line 186, in run
    self.add_units()
  File "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/action/importer.py", line 54, in add_units
    self.env.add_unit(svc.name, mspec)
  File "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/env/go.py", line 28, in add_unit
    return self.client.add_unit(service_name, machine_spec)
  File "/usr/local/lib/python2.7/dist-packages/jujuclient-0.12-py2.7.egg/jujuclient.py", line 465, in add_unit
    "Params": params})
  File "/usr/local/lib/python2.7/dist-packages/jujuclient-0.12-py2.7.egg/jujuclient.py", line 135, in _rpc
    raise EnvError(result)
jujuclient.EnvError: <Env Error - Details:
 { u'Error': u'must add at least one unit', u'RequestId': 1, u'Response': { }}

review: Needs Fixing

[Kapil Thangavelu (hazmat)]

The second one is due to a need for 0.13 for jujuclient, i'll update the
dep spec for that and add some test for the first case.

On Thu, Oct 31, 2013 at 1:41 PM, Adam Gandelman <email address hidden> wrote:

> Review: Needs Fixing
>
> Testing this now, couple of issues so far:
>
> If a service is configured as:
>
> fooservice:
> to: [0]
>
> deployer blows up:
>
> 70, in get_unit_placement
> if ':' in unit_placement:
> TypeError: argument of type 'int' is not iterable
>
> Only running that code if unit_placement is a string seems to fix that.
>
> Adding units fails:
>
> 2013-10-31 17:34:26 [INFO] deployer.import: Adding 2 more units to
> nova-compute
> Traceback (most recent call last):
> File "/usr/local/bin/juju-deployer", line 9, in <module>
> load_entry_point('juju-deployer==0.2.8', 'console_scripts',
> 'juju-deployer')()
> File
> "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/cli.py",
> line 118, in main
> run()
> File
> "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/cli.py",
> line 209, in run
> importer.Importer(env, deployment, options).run()
> File
> "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/action/importer.py",
> line 186, in run
> self.add_units()
> File
> "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/action/importer.py",
> line 54, in add_units
> self.env.add_unit(svc.name, mspec)
> File
> "/usr/local/lib/python2.7/dist-packages/juju_deployer-0.2.8-py2.7.egg/deployer/env/go.py",
> line 28, in add_unit
> return self.client.add_unit(service_name, machine_spec)
> File
> "/usr/local/lib/python2.7/dist-packages/jujuclient-0.12-py2.7.egg/jujuclient.py",
> line 465, in add_unit
> "Params": params})
> File
> "/usr/local/lib/python2.7/dist-packages/jujuclient-0.12-py2.7.egg/jujuclient.py",
> line 135, in _rpc
> raise EnvError(result)
> jujuclient.EnvError: <Env Error - Details:
> { u'Error': u'must add at least one unit', u'RequestId': 1,
> u'Response': { }}
>
> --
>
> https://code.launchpad.net/~hazmat/juju-deployer/unit-placement/+merge/193445
> You are the owner of lp:~hazmat/juju-deployer/unit-placement.
>

[lp:~hazmat/juju-deployer/unit-placement]

89. By Kapil Thangavelu on 2013-10-31

fix for machine 0 placement

[Kapil Thangavelu (hazmat)]

Fixes pushed

[lp:~hazmat/juju-deployer/unit-placement]

90. By Kapil Thangavelu on 2013-10-31

require newer version of jujuclient

91. By Kapil Thangavelu on 2013-11-01

by request do a wait for units before adding relations.

=== added file 'configs/export.yml'
--- configs/export.yml	1970-01-01 00:00:00 +0000
+++ configs/export.yml	2013-11-01 15:46:48 +0000
@@ -0,0 +1,17 @@
+envExport: 
+  services: 
+    mysql: 
+      charm: "cs:precise/mysql-27"
+      annotations: 
+        "gui-x": "-251"
+        "gui-y": "-203"
+    wordpress: 
+      charm: "cs:precise/wordpress-20"
+      num_units: 3
+      to: ['lxc:mysql', 'lxc:mysql']
+      annotations: 
+        "gui-x": "116"
+        "gui-y": "-206"
+  relations: 
+    - - "wordpress:db"
+      - "mysql:db"
 
=== modified file 'deployer/action/diff.py'
--- deployer/action/diff.py	2013-07-22 15:29:31 +0000
+++ deployer/action/diff.py	2013-11-01 15:46:48 +0000
@@ -134,7 +134,7 @@
             if e_v != v:
                 mod['config'] = {k: e_v}
         if e_s['unit_count'] != d_s.get('num_units', 1):
-            mod['num_units'] = e_s['num_units']
+            mod['num_units'] = e_s['unit_count'] - d_s['num_units']
         return mod
 
     def run(self):
 
=== modified file 'deployer/action/importer.py'
--- deployer/action/importer.py	2013-10-02 17:50:05 +0000
+++ deployer/action/importer.py	2013-11-01 15:46:48 +0000
@@ -19,25 +19,41 @@
         self.log.debug("Adding units...")
         # Add units to existing services that don't match count.
         env_status = self.env.status()
-        added = set()
+        reloaded = False
+
         for svc in self.deployment.get_services():
-            delta = (svc.num_units -
-                     len(env_status['services'][svc.name].get('units', ())))
-            if delta > 0:
-                charm = self.deployment.get_charm_for(svc.name)
-                if charm.is_subordinate():
-                    self.log.warning(
-                        "Config specifies num units for subordinate: %s",
-                        svc.name)
-                    continue
-                self.log.info(
-                    "Adding %d more units to %s" % (abs(delta), svc.name))
-                for u in self.env.add_units(svc.name, abs(delta)):
-                    added.add(u)
-            else:
+            cur_units = len(env_status['services'][svc.name].get('units', ()))
+            delta = (svc.num_units - cur_units)
+
+            if delta <= 0:
                 self.log.debug(
                     " Service %r does not need any more units added.",
                     svc.name)
+                continue
+
+            charm = self.deployment.get_charm_for(svc.name)
+            if charm.is_subordinate():
+                self.log.warning(
+                    "Config specifies num units for subordinate: %s",
+                    svc.name)
+                continue
+
+            self.log.info(
+                "Adding %d more units to %s" % (abs(delta), svc.name))
+            if svc.unit_placement:
+                # Reload status once after non placed services units are done.
+                if reloaded is False:
+                    # Crappy workaround juju-core api inconsistency
+                    time.sleep(5.1)
+                    env_status = self.env.status()
+                    reloaded = True
+
+                for mid in range(cur_units, svc.num_units):
+                    mspec = self.deployment.get_unit_placement(
+                        svc, mid, env_status)
+                    self.env.add_unit(svc.name, mspec)
+            else:
+                self.env.add_units(svc.name, abs(delta))
 
     def get_charms(self):
         # Get Charms
@@ -53,6 +69,8 @@
     def deploy_services(self):
         self.log.info("Deploying services...")
         env_status = self.env.status()
+        reloaded = False
+
         for svc in self.deployment.get_services():
             if svc.name in env_status['services']:
                 self.log.debug(
@@ -62,14 +80,28 @@
             charm = self.deployment.get_charm_for(svc.name)
             self.log.info(
                 " Deploying service %s using %s", svc.name, charm.charm_url)
+
+            if svc.unit_placement:
+                # We sorted all the non placed services first, so we only
+                # need to update status once after we're done with them.
+                if not reloaded:
+                    self.log.debug(
+                        " Refetching status for placement deploys")
+                    time.sleep(5.1)
+                    env_status = self.env.status()
+                    reloaded = True
+                num_units = 1
+            else:
+                num_units = svc.num_units
+
             self.env.deploy(
                 svc.name,
                 charm.charm_url,
                 self.deployment.repo_path,
                 svc.config,
                 svc.constraints,
-                svc.num_units,
-                svc.force_machine)
+                num_units,
+                self.deployment.get_unit_placement(svc, 0, env_status))
 
             if svc.expose:
                 self.log.info(" Exposing service %r" % svc.name)
@@ -93,8 +125,8 @@
             self.env.add_relation(end_a, end_b)
             created = True
             # per the original, not sure the use case.
-            self.log.debug(" Waiting 5s before next relation")
-            time.sleep(5)
+            #self.log.debug(" Waiting 5s before next relation")
+            #time.sleep(5)
         return created
 
     def _rel_exists(self, status, end_a, end_b):
@@ -149,17 +181,17 @@
         # to be consistent to subsequent watch api interactions, see
         # http://pad.lv/1203105 which will obviate this wait.
         time.sleep(5.1)
+        self.add_units()
 
+        self.log.debug("Waiting for units before adding relations")
         self.wait_for_units()
-        self.add_units()
 
         rels_created = self.add_relations()
 
         # Wait for the units to be up before waiting for rel stability.
-        self.log.debug("Waiting for units to be started")
-        self.wait_for_units(self.options.retry_count)
         if rels_created:
-            self.log.debug("Waiting for relations %d", self.options.rel_wait)
+            self.log.debug(
+                "Waiting for relation convergence %ds", self.options.rel_wait)
             time.sleep(self.options.rel_wait)
             self.wait_for_units(self.options.retry_count)
 
 
=== modified file 'deployer/deployment.py'
--- deployer/deployment.py	2013-07-24 23:10:15 +0000
+++ deployer/deployment.py	2013-11-01 15:46:48 +0000
@@ -40,8 +40,74 @@
         return Service(name, self.data['services'][name])
 
     def get_services(self):
+        services = []
         for name, svc_data in self.data.get('services', {}).items():
-            yield Service(name, svc_data)
+            services.append(Service(name, svc_data))
+        services.sort(self._placement_sort)
+        return services
+
+    @staticmethod
+    def _placement_sort(svc_a, svc_b):
+        if svc_a.unit_placement:
+            if svc_b.unit_placement:
+                return cmp(svc_a.name, svc_b.name)
+            return 1
+        if svc_b.unit_placement:
+            return -1
+        return cmp(svc_a.name, svc_b.name)
+
+    @staticmethod
+    def _format_placement(machine, container=None):
+        if container:
+            return "%s:%s" % (container, machine)
+        else:
+            return machine
+
+    def get_unit_placement(self, svc, unit_number, status):
+        unit_mapping = svc.unit_placement
+        if not unit_mapping:
+            return None
+        if len(unit_mapping) <= unit_number:
+            return None
+
+        unit_placement = placement = str(unit_mapping[unit_number])
+        container = None
+        u_idx = unit_number
+
+        if ':' in unit_placement:
+            container, placement = unit_placement.split(":")
+        if '=' in placement:
+            placement, u_idx = placement.split("=")
+
+        if placement.isdigit() and placement == "0":
+            return self._format_placement(placement, container)
+
+        with_service = status['services'].get(placement)
+        if with_service is None:
+            # Should be caught in validate relations but sanity check
+            # for concurrency.
+            self.log.error(
+                "Service %s to be deployed with non existant service %s",
+                svc.name, placement)
+            # Prefer continuing deployment with a new machine rather
+            # than an in-progress abort.
+            return None
+
+        svc_units = with_service['units']
+        if len(svc_units) <= unit_number:
+            self.log.warning(
+                "Service:%s deploy-with Service:%s, but no with unit found",
+                svc.name, placement)
+            return None
+        unit_names = svc_units.keys()
+        unit_names.sort()
+        machine = svc_units[unit_names[int(u_idx)]].get('machine')
+        if not machine:
+            self.log.warning(
+                "Service:%s deploy-with unit missing machine %s",
+                svc.name, unit_names[unit_number])
+            return None
+        return self._format_placement(machine, container)
 
     def get_relations(self):
         if 'relations' not in self.data:
@@ -117,6 +183,7 @@
         self.load_overrides(cli_overides)
         self.resolve_config()
         self.validate_relations()
+        self.validate_placement()
 
     def load_overrides(self, cli_overrides=()):
         """Load overrides."""
@@ -195,6 +262,49 @@
                         ep.service, "%s <-> %s" % (e_a, e_b))
                     raise ErrorExit()
 
+    def validate_placement(self):
+        services = dict([(s.name, s) for s in self.get_services()])
+        for name, s in services.items():
+            unit_placement = s.unit_placement
+            if unit_placement is None:
+                continue
+            if not isinstance(unit_placement, list):
+                unit_placement = [unit_placement]
+            unit_placement = map(str, unit_placement)
+            for idx, p in enumerate(unit_placement):
+                if ':' in p:
+                    container, p = p.split(':')
+                    if container not in ('lxc', 'kvm'):
+                        self.log.error(
+                            "Invalid service:%s placement: %s",
+                            name, unit_placement[idx])
+                        raise ErrorExit()
+                if '=' in p:
+                    p, u_idx = p.split("=")
+                    if not u_idx.isdigit():
+                        self.log.error(
+                            "Invalid service:%s placement: %s",
+                            name, unit_placement[idx])
+                        raise ErrorExit()
+                if p.isdigit() and p == '0':
+                    continue
+                elif p.isdigit():
+                    self.log.error(
+                        "Service placement to machine not supported %s to %s",
+                        name, unit_placement[idx])
+                    raise ErrorExit()
+                elif p in services:
+                    if services[p].unit_placement:
+                        self.log.error(
+                            "Nested placement not supported %s -> %s -> %s" % (
+                                name, p, services[p].unit_placement))
+                        raise ErrorExit()
+                else:
+                    self.log.error(
+                        "Invalid service placement %s to %s" % (
+                            name, unit_placement[idx]))
+                    raise ErrorExit()
+
     def save(self, path):
         with open(path, "w") as fh:
             fh.write(yaml_dump(self.data))
 
=== modified file 'deployer/env/base.py'
--- deployer/env/base.py	2013-10-17 03:16:24 +0000
+++ deployer/env/base.py	2013-11-01 15:46:48 +0000
@@ -152,3 +152,6 @@
                 stderr=fh)
         status = yaml_load(output)
         return status
+
+    def add_unit(self, service_name, machine_spec):
+        raise NotImplementedError()
 
=== modified file 'deployer/env/go.py'
--- deployer/env/go.py	2013-10-08 20:13:39 +0000
+++ deployer/env/go.py	2013-11-01 15:46:48 +0000
@@ -5,7 +5,11 @@
 from .base import BaseEnvironment
 from ..utils import ErrorExit
 
-from jujuclient import Environment as EnvironmentClient, UnitErrors, EnvError
+from jujuclient import (
+    Environment as EnvironmentClient,
+    UnitErrors,
+    EnvError,
+    WatchWrapper)
 
 
 class GoEnvironment(BaseEnvironment):
@@ -20,6 +24,9 @@
         config = self._get_env_config()
         return config['admin-secret']
 
+    def add_unit(self, service_name, machine_spec):
+        return self.client.add_unit(service_name, machine_spec)
+
     def add_units(self, service_name, num_units):
         return self.client.add_units(service_name, num_units)
 
@@ -101,17 +108,50 @@
         if len(status['machines']) == 1:
             return
 
-        for mid in status['machines'].keys():
-            if mid == "0":
-                continue
-            self.log.debug("  Terminating machine %s", mid)
-            self.terminate_machine(mid)
+        # containers before machines, container hosts post wait.
+        machines = status['machines'].keys()
+
+        container_hosts = set()
+        containers = set()
+
+        def machine_sort(x, y):
+            for ctype in ('lxc', 'kvm'):
+                for m in (x, y):
+                    if ctype in m:
+                        container_hosts.add(m.split('/', 1)[0])
+                        containers.add(m)
+                        if m == x:
+                            return -1
+                        if m == y:
+                            return 1
+            return cmp(x, y)
+
+        machines.sort(machine_sort)
+
+        for mid in machines:
+            self._terminate_machine(mid, container_hosts)
+
+        if containers:
+            watch = self.client.get_watch(120)
+            WaitForMachineTermination(
+                watch, containers).run(self._delta_event_log)
+
+        for mid in container_hosts:
+            self._terminate_machine(mid)
 
         if terminate_wait:
             self.log.info("  Waiting for machine termination")
             callback = watch and self._delta_event_log or None
             self.client.wait_for_no_machines(None, callback)
 
+    def _terminate_machine(self, mid, container_hosts=()):
+        if mid == "0":
+            return
+        if mid in container_hosts:
+            return
+        self.log.debug("  Terminating machine %s", mid)
+        self.terminate_machine(mid)
+
     def _check_timeout(self, etime):
         w_timeout = etime - time.time()
         if w_timeout < 0:
@@ -211,3 +251,25 @@
             eps[0]['Relation']['Name'],
             eps[1]['ServiceName'],
             eps[1]['Relation']['Name'])
+
+
+class WaitForMachineTermination(WatchWrapper):
+
+    def __init__(self, watch, machines):
+        super(WaitForMachineTermination, self).__init__(watch)
+        self.machines = set(machines)
+        self.known = set()
+
+    def process(self, entity_type, change, data):
+        if entity_type != 'machine':
+            return
+        if change == 'remove' and data['Id'] in self.machines:
+            self.machines.remove(data['Id'])
+        else:
+            self.known.add(data['Id'])
+
+    def complete(self):
+        for m in self.machines:
+            if m in self.known:
+                return False
+        return True
 
=== modified file 'deployer/service.py'
--- deployer/service.py	2013-09-13 13:36:22 +0000
+++ deployer/service.py	2013-11-01 15:46:48 +0000
@@ -4,6 +4,9 @@
         self.svc_data = svc_data
         self.name = name
 
+    def __repr__(self):
+        return "<Service %s>" % (self.name)
+
     @property
     def config(self):
         return self.svc_data.get('options', None)
@@ -17,9 +20,14 @@
         return int(self.svc_data.get('num_units', 1))
 
     @property
-    def force_machine(self):
-        return self.svc_data.get('to') or self.svc_data.get(
-            'force-machine')
+    def unit_placement(self):
+        # Separate checks to support machine 0 placement.
+        value = self.svc_data.get('to')
+        if value is None:
+            value = self.svc_data.get('force-machine')
+        if value is not None and not isinstance(value, list):
+            value = [value]
+        return value or []
 
     @property
     def expose(self):
 
=== modified file 'deployer/tests/test_config.py'
--- deployer/tests/test_config.py	2013-10-10 21:18:38 +0000
+++ deployer/tests/test_config.py	2013-11-01 15:46:48 +0000
@@ -54,7 +54,6 @@
                   config.get('my-files-frontend-dev').get_services()]
         self.assertTrue(set(wordpress).issubset(set(my_app)))
 
-
     def test_inherits_config_overridden(self):
         config = ConfigStack([
             os.path.join(self.test_data_dir, "stack-default.cfg"),
@@ -66,12 +65,12 @@
         # over-ridden
         self.assertEquals(db.config.get('tuning-level'), 'fastest')
 
-
     def test_multi_inheritance_multi_files(self):
         config = ConfigStack([
             os.path.join(self.test_data_dir, "openstack", "openstack.cfg"),
             os.path.join(self.test_data_dir, "openstack", "ubuntu_base.cfg"),
-            os.path.join(self.test_data_dir, "openstack", "openstack_base.cfg"),
+            os.path.join(
+                self.test_data_dir, "openstack", "openstack_base.cfg"),
         ])
         self._test_multiple_inheritance(config)
 
@@ -107,7 +106,7 @@
 
         deployment = config.get('precise-grizzly')
         services = [s.name for s in list(deployment.get_services())]
-        self.assertEquals(['nova-cloud-controller', 'mysql'], services)
+        self.assertEquals(['mysql', 'nova-cloud-controller'], services)
 
         nova = deployment.get_service('nova-cloud-controller')
         self.assertEquals(nova.config['openstack-origin'],
@@ -116,8 +115,8 @@
         deployment = config.get('precise-grizzly-quantum')
         services = [s.name for s in list(deployment.get_services())]
         self.assertEquals(services,
-                          ['quantum-gateway', 'nova-cloud-controller',
-                           'mysql'])
+                          ['mysql', 'nova-cloud-controller',
+                           'quantum-gateway'])
         nova = deployment.get_service('nova-cloud-controller')
         self.assertEquals(nova.config['network-manager'], 'Quantum')
         self.assertEquals(nova.config['openstack-origin'],
 
=== added file 'deployer/tests/test_data/stack-placement-invalid-2.yaml'
--- deployer/tests/test_data/stack-placement-invalid-2.yaml	1970-01-01 00:00:00 +0000
+++ deployer/tests/test_data/stack-placement-invalid-2.yaml	2013-11-01 15:46:48 +0000
@@ -0,0 +1,13 @@
+stack:
+  series: precise
+  services:
+    nova-compute:
+      charm: cs:precise/nova-compute
+      units: 3
+    ceph:
+      units: 3
+      to: [nova-compute, nova-compute, nova-compute]
+    mysql:
+      to: lxc:nova-compute
+    wordpress:
+      to: lxc:foobar
 
=== added file 'deployer/tests/test_data/stack-placement-invalid.yaml'
--- deployer/tests/test_data/stack-placement-invalid.yaml	1970-01-01 00:00:00 +0000
+++ deployer/tests/test_data/stack-placement-invalid.yaml	2013-11-01 15:46:48 +0000
@@ -0,0 +1,13 @@
+stack:
+  series: precise
+  services:
+    nova-compute:
+      charm: cs:precise/nova-compute
+      units: 3
+    ceph:
+      units: 3
+      to: [nova-compute, nova-compute, nova-compute]
+    mysql:
+      to: lxc:nova-compute
+    wordpress:
+      to: lxc:mysql
 
=== added file 'deployer/tests/test_data/stack-placement.yaml'
--- deployer/tests/test_data/stack-placement.yaml	1970-01-01 00:00:00 +0000
+++ deployer/tests/test_data/stack-placement.yaml	2013-11-01 15:46:48 +0000
@@ -0,0 +1,18 @@
+stack:
+  series: precise
+  services:
+    nova-compute:
+      charm: cs:precise/nova-compute
+      units: 3
+    ceph:
+      units: 3
+      to: [nova-compute, nova-compute]
+    mysql:
+      to: 0
+    quantum:
+      units: 4
+      to: ["lxc:nova-compute", "lxc:nova-compute", "lxc:nova-compute", "lxc:nova-compute"]
+    verity:
+      to: lxc:nova-compute=2
+    semper:
+      to: nova-compute=2
 
=== modified file 'deployer/tests/test_deployment.py'
--- deployer/tests/test_deployment.py	2013-07-24 23:10:15 +0000
+++ deployer/tests/test_deployment.py	2013-11-01 15:46:48 +0000
@@ -5,7 +5,7 @@
 
 from deployer.config import ConfigStack
 from deployer.deployment import Deployment
-from deployer.utils import setup_logging
+from deployer.utils import setup_logging, ErrorExit
 
 from .base import Base
 
@@ -16,6 +16,11 @@
         self.output = setup_logging(
             debug=True, verbose=True, stream=StringIO.StringIO())
 
+    def get_named_deployment(self, file_name, stack_name):
+        return ConfigStack(
+            [os.path.join(
+                self.test_data_dir, file_name)]).get(stack_name)
+
     def test_deployer(self):
         d = ConfigStack(
             [os.path.join(
@@ -51,6 +56,66 @@
             list(d.get_relations()),
             [('blog', 'db'), ('blog', 'cache'), ('blog', 'haproxy')])
 
+    def test_validate_placement_sorting(self):
+        d = self.get_named_deployment("stack-placement.yaml", "stack")
+        services = d.get_services()
+        self.assertEqual(services[0].name, 'nova-compute')
+        try:
+            d.validate_placement()
+        except ErrorExit:
+            self.fail("Should not fail")
+
+    def test_validate_invalid_placement_nested(self):
+        d = self.get_named_deployment("stack-placement-invalid.yaml", "stack")
+        services = d.get_services()
+        self.assertEqual(services[0].name, 'nova-compute')
+        try:
+            d.validate_placement()
+        except ErrorExit:
+            pass
+        else:
+            self.fail("Should fail")
+
+    def test_validate_invalid_placement_no_with_service(self):
+        d = self.get_named_deployment(
+            "stack-placement-invalid-2.yaml", "stack")
+        services = d.get_services()
+        self.assertEqual(services[0].name, 'nova-compute')
+        try:
+            d.validate_placement()
+        except ErrorExit:
+            pass
+        else:
+            self.fail("Should fail")
+
+    def test_get_unit_placement(self):
+        d = self.get_named_deployment("stack-placement.yaml", "stack")
+        status = {
+            'services': {
+                'nova-compute': {
+                    'units': {
+                        'nova-compute/2': {'machine': '1'},
+                        'nova-compute/3': {'machine': '2'},
+                        'nova-compute/4': {'machine': '3'}}}}}
+        svc = d.get_service('ceph')
+        self.assertEqual(d.get_unit_placement(svc, 0, status), '1')
+        self.assertEqual(d.get_unit_placement(svc, 1, status), '2')
+        self.assertEqual(d.get_unit_placement(svc, 2, status), None)
+
+        svc = d.get_service('quantum')
+        self.assertEqual(d.get_unit_placement(svc, 0, status), 'lxc:1')
+        self.assertEqual(d.get_unit_placement(svc, 2, status), 'lxc:3')
+        self.assertEqual(d.get_unit_placement(svc, 3, status), None)
+
+        svc = d.get_service('verity')
+        self.assertEqual(d.get_unit_placement(svc, 0, status), 'lxc:3')
+
+        svc = d.get_service('mysql')
+        self.assertEqual(d.get_unit_placement(svc, 0, status), '0')
+
+        svc = d.get_service('semper')
+        self.assertEqual(d.get_unit_placement(svc, 0, status), '3')
+
     def test_multiple_relations_no_weight(self):
         data = {"relations": {"wordpress": {"consumes": ["mysql"]},
                               "nginx": {"consumes": ["wordpress"]}}}
 
=== modified file 'doc/config.rst'
--- doc/config.rst	2013-05-16 03:20:42 +0000
+++ doc/config.rst	2013-11-01 15:46:48 +0000
@@ -94,3 +94,57 @@
             constraints: mem=16
             options:
                 tuning: optimized
+
+
+Placement
+=========
+
+Flexible unit placement can be specified via deployer. Primarily this is via
+specifying service units deployments alongside those of another service.
+
+Each unit's placement must be specified individually, absence of placement for
+a unit results in juju default behavior for the given constraints.
+
+One special placement form is machine placement, which only allowed to machine 0,
+as other machine identities are ambigious for most usage scenarios.
+
+Both container and hulk-smash placement are supported. Different
+containerization and deploy with services can be mixed.
+
+The deployed-with service must have enough units to hold # # Nested
+to: specifications are not supported (ie in the below wordpress can't
+# be deployed to mysql because mysql already specifies a 'to'
+placement)
+
+Example::
+  envExport:
+    services:
+      mysql:
+        # The only machine id supported is machine 0
+        to: 0
+      wordpress:
+        units: 3
+      redis-server:
+        units: 3
+        to: [lxc:wordpress, wordpress]
+      ceph:
+        units: 4
+        to: [wordpress, wordpress, wordpress, wordpress]
+      serenade:
+        to: lxc:wordpress=2
+
+In this case the first unit of redis-server is deployed in a container
+on wordpress/0 The second unit of redis-server is deployed hulk smash
+onto wordpress/1 The third unit of redis-server gets a full machine
+allocated to itself.
+
+For ceph, we deploy hulk smash of the first 3 units, the final unit doesn't 
+have a corresponding unit of wordpress and is deployed (along with a console
+warning) to a separate machine per its default constraints.
+
+The serenade service is overriding the default deploy-with unit by
+explicitly specifying a unit index for the deployment. These are not
+unit id based but rather zero based offsets into a sorted list of
+units.
+
+       
 
=== modified file 'setup.py'
--- setup.py	2013-10-11 17:01:16 +0000
+++ setup.py	2013-11-01 15:46:48 +0000
@@ -12,7 +12,7 @@
     author="Kapil Thangavelu",
     author_email="[e-mail]",
     url="http://launchpad.net/juju-deployer",
-    install_requires=["jujuclient >= 0.0.7"],
+    install_requires=["jujuclient >= 0.13"],
     packages=find_packages(),
     classifiers=[
         "Development Status :: 2 - Pre-Alpha",