inventory/aws_ec2: allow multi-entries for one host

Add an option to allow multiple duplicated entry for on single instance.

Closes: ansible-collections#950

plugins/inventory/aws_ec2.py

@@ -176,6 +176,9 @@
     separator: '-'       # Hostname will be aws-test_literal
     prefix: 'aws'
 
+# Returns all the hostnames for a given instance
+allow_duplicated_hosts: False
+
 # Example using constructed features to create groups and set ansible_host
 plugin: aws_ec2
 regions:
@@ -626,7 +629,7 @@ def _sanitize_hostname(self, hostname):
         else:
             return to_text(hostname)
 
-    def _get_hostname(self, instance, hostnames):
+    def _get_preferred_hostname(self, instance, hostnames):
         '''
             :param instance: an instance dict returned by boto3 ec2 describe_instances()
             :param hostnames: a list of hostname destination variables in order of preference
@@ -635,14 +638,47 @@ def _get_hostname(self, instance, hostnames):
         if not hostnames:
             hostnames = ['dns-name', 'private-dns-name']
 
+        hostname = None
+        for preference in hostnames:
+            if isinstance(preference, dict):
+                if 'name' not in preference:
+                    raise AnsibleError("A 'name' key must be defined in a hostnames dictionary.")
+                hostname = self._get_preferred_hostname(instance, [preference["name"]])
+                hostname_from_prefix = self._get_preferred_hostname(instance, [preference["prefix"]])
+                separator = preference.get("separator", "_")
+                if hostname and hostname_from_prefix and 'prefix' in preference:
+                    hostname = hostname_from_prefix + separator + hostname
+            elif preference.startswith('tag:'):
+                tags = self._get_tag_hostname(preference, instance)
+                hostname = tags[0] if tags else None
+            else:
+                hostname = self._get_boto_attr_chain(preference, instance)
+            if hostname:
+                break
+        if hostname:
+            if ':' in to_text(hostname):
+                return self._sanitize_group_name((to_text(hostname)))
+            else:
+                return to_text(hostname)
+
+
+    def get_all_hostnames(self, instance, hostnames):
+        '''
+            :param instance: an instance dict returned by boto3 ec2 describe_instances()
+            :param hostnames: a list of hostname destination variables
+            :return all the candidats matching the expectation
+        '''
+        if not hostnames:
+            hostnames = ['dns-name', 'private-dns-name']
+
         hostname = None
         hostname_list = []
         for preference in hostnames:
             if isinstance(preference, dict):
                 if 'name' not in preference:
                     raise AnsibleError("A 'name' key must be defined in a hostnames dictionary.")
-                hostname = self._get_hostname(instance, [preference["name"]])
-                hostname_from_prefix = self._get_hostname(instance, [preference["prefix"]])
+                hostname = self.get_all_hostnames(instance, [preference["name"]])
+                hostname_from_prefix = self.get_all_hostnames(instance, [preference["prefix"]])
                 separator = preference.get("separator", "_")
                 if hostname and hostname_from_prefix and 'prefix' in preference:
                     hostname = hostname_from_prefix[0] + separator + hostname[0]
@@ -689,20 +725,27 @@ def _query(self, regions, include_filters, exclude_filters, strict_permissions):
 
         return {'aws_ec2': instances}
 
-    def _populate(self, groups, hostnames):
+    def _populate(self, groups, hostnames, allow_duplicated_hosts=False):
         for group in groups:
             group = self.inventory.add_group(group)
-            self._add_hosts(hosts=groups[group], group=group, hostnames=hostnames)
+            self._add_hosts(
+                hosts=groups[group],
+                group=group,
+                hostnames=hostnames,
+                allow_duplicated_hosts=allow_duplicated_hosts)
             self.inventory.add_child('all', group)
 
-    def _add_hosts(self, hosts, group, hostnames):
+    def _add_hosts(self, hosts, group, hostnames, allow_duplicated_hosts=False):
         '''
             :param hosts: a list of hosts to be added to a group
             :param group: the name of the group to which the hosts belong
             :param hostnames: a list of hostname destination variables in order of preference
         '''
         for host in hosts:
-            hostname_list = self._get_hostname(host, hostnames)
+            if allow_duplicated_hosts:
+                hostname_list = self.get_all_hostnames(host, hostnames)
+            else:
+                hostname_list = [self._get_preferred_hostname(host, hostnames)]
 
             host = camel_dict_to_snake_dict(host, ignore_list=['Tags'])
             host['tags'] = boto3_tag_list_to_ansible_dict(host.get('tags', []))
@@ -820,6 +863,7 @@ def parse(self, inventory, loader, path, cache=True):
         exclude_filters = self.get_option('exclude_filters')
         hostnames = self.get_option('hostnames')
         strict_permissions = self.get_option('strict_permissions')
+        allow_duplicated_hosts = self.get_option('allow_duplicated_hosts')
 
         cache_key = self.get_cache_key(path)
         # false when refresh_cache or --flush-cache is used
@@ -839,7 +883,7 @@ def parse(self, inventory, loader, path, cache=True):
         if not cache or cache_needs_update:
             results = self._query(regions, include_filters, exclude_filters, strict_permissions)
 
-        self._populate(results, hostnames)
+        self._populate(results, hostnames, allow_duplicated_hosts=allow_duplicated_hosts)
 
         # If the cache has expired/doesn't exist or if refresh_inventory/flush cache is used
         # when the user is using caching, update the cached inventory

tests/unit/plugins/inventory/test_aws_ec2.py

@@ -139,21 +139,51 @@ def test_boto3_conn(inventory):
             assert "Insufficient credentials found" in error_message
 
 
-def test_get_hostname_default(inventory):
+def testget_all_hostnames_default(inventory):
     instance = instances['Instances'][0]
-    assert inventory._get_hostname(instance, hostnames=None)[0] == "ec2-12-345-67-890.compute-1.amazonaws.com"
+    assert inventory.get_all_hostnames(instance, hostnames=None) == ["ec2-12-345-67-890.compute-1.amazonaws.com", "ip-098-76-54-321.ec2.internal"]
 
 
-def test_get_hostname(inventory):
+def testget_all_hostnames(inventory):
     hostnames = ['ip-address', 'dns-name']
     instance = instances['Instances'][0]
-    assert inventory._get_hostname(instance, hostnames)[0] == "12.345.67.890"
+    assert inventory.get_all_hostnames(instance, hostnames) == ["12.345.67.890", "ec2-12-345-67-890.compute-1.amazonaws.com"]
 
 
-def test_get_hostname_dict(inventory):
+def testget_all_hostnames_dict(inventory):
     hostnames = [{'name': 'private-ip-address', 'separator': '_', 'prefix': 'tag:Name'}]
     instance = instances['Instances'][0]
-    assert inventory._get_hostname(instance, hostnames)[0] == "aws_ec2_098.76.54.321"
+    assert inventory.get_all_hostnames(instance, hostnames) == ["aws_ec2_098.76.54.321"]
+
+
+def testget_all_hostnames_with_2_tags(inventory):
+    hostnames = ['tag:ansible', 'tag:Name']
+    instance = instances['Instances'][0]
+    assert inventory.get_all_hostnames(instance, hostnames) == ["test", "aws_ec2"]
+
+
+
+def test_get_preferred_hostname_default(inventory):
+    instance = instances['Instances'][0]
+    assert inventory._get_preferred_hostname(instance, hostnames=None) == "ec2-12-345-67-890.compute-1.amazonaws.com"
+
+
+def test_get_preferred_hostname(inventory):
+    hostnames = ['ip-address', 'dns-name']
+    instance = instances['Instances'][0]
+    assert inventory._get_preferred_hostname(instance, hostnames) == "12.345.67.890"
+
+
+def test_get_preferred_hostname_dict(inventory):
+    hostnames = [{'name': 'private-ip-address', 'separator': '_', 'prefix': 'tag:Name'}]
+    instance = instances['Instances'][0]
+    assert inventory._get_preferred_hostname(instance, hostnames) == "aws_ec2_098.76.54.321"
+
+
+def test_get_preferred_hostname_with_2_tags(inventory):
+    hostnames = ['tag:ansible', 'tag:Name']
+    instance = instances['Instances'][0]
+    assert inventory._get_preferred_hostname(instance, hostnames) == "test"
 
 
 def test_set_credentials(inventory):
@@ -216,3 +246,8 @@ def test_include_filters_with_filter_and_include_filters(inventory):
     assert inventory.build_include_filters() == [
         {"from_filter": 1},
         {"from_include_filter": "bar"}]
+
+
+def test_add_host(inventory):
+    # TODO
+    inventory.add_hosts()