Add support for shared ansible_host in inventory

Today it is possible to create the following ansible inventory file:

  [foo]
  foo01 ansible_host=192.168.1.1

  [bar]
  bar01 ansible_host=192.168.1.1

Which allows a user to create multiple host aliases for a single
connection. This could be done with ansible groups, however there is
some functional differences on how ansible runs in that configuration.

We could also request 2 nodes from nodepool, however in this case, it
would be a waste of CI resources because every alias would need a new
node from nodepool.

Now, a user is able to alias multiple host names to a single node from
nodepool by doing the following:

  nodeset:
    nodes:
      - name:
          - foo
          - bar
        label: ubuntu-xenial

This would result in a single node request from nodepool, but create
an inventory file with 2 alaises sharing and single ansible_host
variable.

Change-Id: I674d6baac26852ee1503feb1ed16c279bf773688
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

doc/source/user/config.rst

@@ -1201,7 +1201,9 @@ configuration may be simplified.
            label: controller-label
          - name: compute1
            label: compute-label
-         - name: compute2
+         - name:
+             - compute2
+             - web
            label: compute-label
        groups:
          - name: ceph-osd
@@ -1212,6 +1214,9 @@ configuration may be simplified.
              - controller
              - compute1
              - compute2
+          - name: ceph-web
+            nodes:
+              - web
 
 .. attr:: nodeset
 
@@ -1233,6 +1238,9 @@ configuration may be simplified.
          The name of the node.  This will appear in the Ansible inventory
          for the job.
 
+         This can also be as a list of strings. If so, then the list of hosts in
+         the Ansible inventory will share a common ansible_host address.
+
       .. attr:: label
          :required:
 

tests/base.py

@@ -1412,7 +1412,7 @@ class RecordingAnsibleJob(zuul.executor.server.AnsibleJob):
             host['host_vars']['ansible_connection'] = 'local'
 
         hosts.append(dict(
-            name='localhost',
+            name=['localhost'],
             host_vars=dict(ansible_connection='local'),
             host_keys=[]))
         return hosts

tests/fixtures/config/inventory/git/common-config/zuul.yaml

@@ -43,6 +43,16 @@
           label: ubuntu-xenial
     run: playbooks/single-inventory.yaml
 
+- job:
+    name: single-inventory-list
+    nodeset:
+      nodes:
+        - name:
+            - compute
+            - controller
+          label: ubuntu-xenial
+    run: playbooks/single-inventory.yaml
+
 - job:
     name: group-inventory
     nodeset: nodeset1

tests/fixtures/config/inventory/git/org_project/.zuul.yaml

@@ -3,4 +3,5 @@
     check:
       jobs:
         - single-inventory
+        - single-inventory-list
         - group-inventory

tests/unit/test_inventory.py

@@ -57,6 +57,26 @@ class TestInventory(ZuulTestCase):
         self.executor_server.release()
         self.waitUntilSettled()
 
+    def test_single_inventory_list(self):
+
+        inventory = self._get_build_inventory('single-inventory-list')
+
+        all_nodes = ('compute', 'controller')
+        self.assertIn('all', inventory)
+        self.assertIn('hosts', inventory['all'])
+        self.assertIn('vars', inventory['all'])
+        for node_name in all_nodes:
+            self.assertIn(node_name, inventory['all']['hosts'])
+        self.assertIn('zuul', inventory['all']['vars'])
+        z_vars = inventory['all']['vars']['zuul']
+        self.assertIn('executor', z_vars)
+        self.assertIn('src_root', z_vars['executor'])
+        self.assertIn('job', z_vars)
+        self.assertEqual(z_vars['job'], 'single-inventory-list')
+
+        self.executor_server.release()
+        self.waitUntilSettled()
+
     def test_group_inventory(self):
 
         inventory = self._get_build_inventory('group-inventory')

tests/unit/test_nodepool.py

@@ -67,8 +67,8 @@ class TestNodepool(BaseTestCase):
         # Test a simple node request
 
         nodeset = model.NodeSet()
-        nodeset.addNode(model.Node('controller', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['controller', 'foo'], 'ubuntu-xenial'))
-        nodeset.addNode(model.Node('compute', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['compute'], 'ubuntu-xenial'))
         job = model.Job('testjob')
         job.nodeset = nodeset
         request = self.nodepool.requestNodes(None, job)
@@ -99,8 +99,8 @@ class TestNodepool(BaseTestCase):
         # Test that node requests are re-submitted after disconnect
 
         nodeset = model.NodeSet()
-        nodeset.addNode(model.Node('controller', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['controller'], 'ubuntu-xenial'))
-        nodeset.addNode(model.Node('compute', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['compute'], 'ubuntu-xenial'))
         job = model.Job('testjob')
         job.nodeset = nodeset
         self.fake_nodepool.paused = True
@@ -116,8 +116,8 @@ class TestNodepool(BaseTestCase):
         # Test that node requests can be canceled
 
         nodeset = model.NodeSet()
-        nodeset.addNode(model.Node('controller', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['controller'], 'ubuntu-xenial'))
-        nodeset.addNode(model.Node('compute', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['compute'], 'ubuntu-xenial'))
         job = model.Job('testjob')
         job.nodeset = nodeset
         self.fake_nodepool.paused = True
@@ -131,8 +131,8 @@ class TestNodepool(BaseTestCase):
         # Test that a resubmitted request would not lock nodes
 
         nodeset = model.NodeSet()
-        nodeset.addNode(model.Node('controller', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['controller'], 'ubuntu-xenial'))
-        nodeset.addNode(model.Node('compute', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['compute'], 'ubuntu-xenial'))
         job = model.Job('testjob')
         job.nodeset = nodeset
         request = self.nodepool.requestNodes(None, job)
@@ -152,8 +152,8 @@ class TestNodepool(BaseTestCase):
         # Test that a lost request would not lock nodes
 
         nodeset = model.NodeSet()
-        nodeset.addNode(model.Node('controller', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['controller'], 'ubuntu-xenial'))
-        nodeset.addNode(model.Node('compute', 'ubuntu-xenial'))
+        nodeset.addNode(model.Node(['compute'], 'ubuntu-xenial'))
         job = model.Job('testjob')
         job.nodeset = nodeset
         request = self.nodepool.requestNodes(None, job)

zuul/configloader.py

@@ -340,7 +340,7 @@ class PragmaParser(object):
 class NodeSetParser(object):
     @staticmethod
     def getSchema(anonymous=False):
-        node = {vs.Required('name'): str,
+        node = {vs.Required('name'): to_list(str),
                 vs.Required('label'): str,
                 }
 
@@ -365,11 +365,13 @@ class NodeSetParser(object):
         node_names = set()
         group_names = set()
         for conf_node in as_list(conf['nodes']):
-            if conf_node['name'] in node_names:
+            for name in as_list(conf_node['name']):
-                raise DuplicateNodeError(conf['name'], conf_node['name'])
+                if name in node_names:
-            node = model.Node(conf_node['name'], conf_node['label'])
+                    raise DuplicateNodeError(name, conf_node['name'])
+            node = model.Node(as_list(conf_node['name']), conf_node['label'])
             ns.addNode(node)
-            node_names.add(conf_node['name'])
+            for name in as_list(conf_node['name']):
+                node_names.add(name)
         for conf_group in as_list(conf.get('groups', [])):
             for node_name in as_list(conf_group['nodes']):
                 if node_name not in node_names:

zuul/executor/server.py

@@ -495,7 +495,8 @@ def make_inventory_dict(nodes, groups, all_vars):
 
     hosts = {}
     for node in nodes:
-        hosts[node['name']] = node['host_vars']
+        for name in node['name']:
+            hosts[name] = node['host_vars']
 
     inventory = {
         'all': {

zuul/model.py

@@ -497,9 +497,10 @@ class NodeSet(object):
         return n
 
     def addNode(self, node):
-        if node.name in self.nodes:
+        for name in node.name:
-            raise Exception("Duplicate node in %s" % (self,))
+            if name in self.nodes:
-        self.nodes[node.name] = node
+                raise Exception("Duplicate node in %s" % (self,))
+        self.nodes[tuple(node.name)] = node
 
     def getNodes(self):
         return list(self.nodes.values())