Merge 42bed001b7 into 7f17759bfe

changelogs/fragments/86140-inventory-limit-implicit-localhost.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - "inventory - Refactored pattern evaluation to use a filter-based approach, eliminating duplicate work and properly preserving implicit localhost (https://github.com/ansible/ansible/issues/86140)."

lib/ansible/inventory/data.py

@@ -63,8 +63,10 @@ class InventoryData:
 
     def _create_implicit_localhost(self, pattern: str) -> Host:
 
-        if self.localhost:
+        if self.localhost and self.localhost.implicit:
             new_host = self.localhost
+        elif self.localhost:
+            return None
         else:
             new_host = Host(pattern)
 

lib/ansible/inventory/manager.py

@@ -44,6 +44,7 @@ from ansible.utils.vars import combine_vars
 from ansible.vars.plugins import get_vars_from_inventory_sources
 
 if t.TYPE_CHECKING:
+    from ansible.inventory.host import Host
     from ansible.plugins.inventory import BaseInventoryPlugin
 
 display = Display()
@@ -67,10 +68,13 @@ PATTERN_WITH_SUBSCRIPT = re.compile(
 )
 
 
-def order_patterns(patterns):
-    """ takes a list of patterns and reorders them by modifier to apply them consistently """
+def order_patterns(patterns: list[str]) -> tuple[list[str], list[str], list[str]]:
+    """
+    Takes a list of patterns and groups them by modifier.
+    Returns tuple of (regular_patterns, intersection_patterns, exclude_patterns).
+    Regular patterns are unioned, then intersections applied, then exclusions.
+    """
 
-    # FIXME: this goes away if we apply patterns incrementally or by groups
     pattern_regular = []
     pattern_intersection = []
     pattern_exclude = []
@@ -85,14 +89,7 @@ def order_patterns(patterns):
         else:
             pattern_regular.append(p)
 
-    # if no regular pattern was given, hence only exclude and/or intersection
-    # make that magically work
-    if pattern_regular == []:
-        pattern_regular = ['all']
-
-    # when applying the host selectors, run those without the "&" or "!"
-    # first, then the &s, then the !s.
-    return pattern_regular + pattern_intersection + pattern_exclude
+    return pattern_regular, pattern_intersection, pattern_exclude
 
 
 def split_host_pattern(pattern):
@@ -407,17 +404,15 @@ class InventoryManager(object):
 
             if pattern_hash not in self._hosts_patterns_cache:
 
-                patterns = split_host_pattern(pattern)
-                hosts = self._evaluate_patterns(patterns)
+                hosts = list(self._inventory.hosts.values())
 
-                # mainly useful for hostvars[host] access
                 if not ignore_limits and self._subset:
-                    # exclude hosts not in a subset, if defined
-                    subset_uuids = set(s._uuid for s in self._evaluate_patterns(self._subset))
-                    hosts = [h for h in hosts if h._uuid in subset_uuids]
+                    hosts = self._evaluate_patterns(self._subset, hosts)
+
+                patterns = split_host_pattern(pattern)
+                hosts = self._evaluate_patterns(patterns, hosts)
 
                 if not ignore_restrictions and self._restriction:
-                    # exclude hosts mentioned in any restriction (ex: failed hosts)
                     hosts = [h for h in hosts if h.name in self._restriction]
 
                 self._hosts_patterns_cache[pattern_hash] = deduplicate_list(hosts)
@@ -436,30 +431,41 @@ class InventoryManager(object):
 
         return hosts
 
-    def _evaluate_patterns(self, patterns):
+    def _evaluate_patterns(self, patterns: list[str], hosts: list[Host]) -> list[Host]:
         """
-        Takes a list of patterns and returns a list of matching host names,
-        taking into account any negative and intersection patterns.
+        Filters a list of hosts by applying patterns.
         """
 
-        patterns = order_patterns(patterns)
-        hosts = []
+        pattern_regular, pattern_intersection, pattern_exclude = order_patterns(patterns)
+        hosts_set = set(hosts)
 
-        for p in patterns:
-            # avoid resolving a pattern that is a plain host
-            if p in self._inventory.hosts:
-                hosts.append(self._inventory.get_host(p))
-            else:
-                that = self._match_one_pattern(p)
-                if p[0] == "!":
-                    that = set(that)
-                    hosts = [h for h in hosts if h not in that]
-                elif p[0] == "&":
-                    that = set(that)
-                    hosts = [h for h in hosts if h in that]
+        if pattern_regular:
+            matched = set()
+            for p in pattern_regular:
+                if p in self._inventory.hosts:
+                    target_host = self._inventory.get_host(p)
+                    if target_host in hosts_set:
+                        matched.add(target_host)
                 else:
-                    existing_hosts = set(y.name for y in hosts)
-                    hosts.extend([h for h in that if h.name not in existing_hosts])
+                    that = self._match_one_pattern(p)
+                    matched.update(h for h in that if h in hosts_set or h.implicit)
+
+            hosts = [h for h in hosts if h in matched]
+            for h in matched - hosts_set:
+                if h.implicit:
+                    hosts.append(h)
+            hosts_set = matched
+
+        for p in pattern_intersection:
+            that = set(self._match_one_pattern(p))
+            hosts = [h for h in hosts if h in that]
+            hosts_set = hosts_set & that
+
+        for p in pattern_exclude:
+            that = set(self._match_one_pattern(p))
+            hosts = [h for h in hosts if h not in that]
+            hosts_set = hosts_set - that
+
         return hosts
 
     def _match_one_pattern(self, pattern):

test/integration/targets/limit_inventory/exclude_localhost.yml

@@ -0,0 +1,10 @@
+- hosts: all,localhost
+  gather_facts: false
+  tasks:
+    - debug:
+        msg: "Host: {{ inventory_hostname }}"
+
+    - assert:
+        that:
+          - inventory_hostname != 'localhost'
+        fail_msg: "localhost should have been excluded by limit"

test/integration/targets/limit_inventory/hosts_with_localhost.yml

@@ -0,0 +1,6 @@
+all:
+  hosts:
+    host1:
+    host2:
+    host3:
+    localhost:

test/integration/targets/limit_inventory/include_localhost.yml

@@ -0,0 +1,10 @@
+- hosts: all,localhost
+  gather_facts: false
+  tasks:
+    - set_fact:
+        include_localhost: true
+
+    - assert:
+        that:
+          - hostvars.localhost.include_localhost is true
+      run_once: true

test/integration/targets/limit_inventory/runme.sh

@@ -29,3 +29,21 @@ ansible -i hosts.yml host1,,host3 --list-hosts | tee out ; grep -q 'hosts (2)' o
 ansible -i hosts.yml all --limit 'host1, ,    ,host3' --list-hosts | tee out ; grep -q 'hosts (2)' out
 ansible -i hosts.yml 'host1, ,    ,host3' --list-hosts | tee out ; grep -q 'hosts (2)' out
 
+# Intersection patterns with limits
+ansible -i hosts.yml all --limit '&host1' --list-hosts | tee out ; grep -q 'hosts (1)' out
+
+# Multiple negations
+ansible -i hosts.yml all --limit '!host1:!host2' --list-hosts | tee out ; grep -q 'hosts (1)' out
+ansible -i hosts.yml all --limit '!host1,!host2' --list-hosts | tee out ; grep -q 'hosts (1)' out
+
+# Negation-only limit with 'all' pattern (shouldn't add implicit localhost)
+ansible -i hosts.yml all --limit '!host2' --list-hosts | tee out ; grep -q 'hosts (2)' out
+
+# ensure implicit localhost available with limits when explicitly in play pattern
+ansible-playbook -i hosts.yml --limit '!host2' include_localhost.yml
+
+# Explicitly excluding localhost should work when inventory has explicit localhost
+ansible-playbook -i hosts_with_localhost.yml --limit '!localhost' exclude_localhost.yml
+
+# localhost-only play with non-localhost limit should still include localhost
+ansible -i hosts.yml localhost --limit 'host1' --list-hosts | tee out ; grep -q 'hosts (1)' out