Move hosts container to hostaddress

 * make it a frozen dataclass
 * rename to `Hosts`---it's a container of hosts, independently
   of how it gets its filled

CMK-14467

Change-Id: I644e98db2ca8e212bbbbeae584998eae37aaafde

cmk/base/config.py

@@ -21,7 +21,6 @@
 import socket
 import struct
 import sys
-from collections import Counter
 from collections.abc import (
     Callable,
     Container,
@@ -62,7 +61,7 @@
 )
 from cmk.utils.config_path import ConfigPath
 from cmk.utils.exceptions import MKGeneralException, MKIPAddressLookupError, MKTerminate, OnError
-from cmk.utils.hostaddress import HostAddress, HostName
+from cmk.utils.hostaddress import HostAddress, HostName, Hosts
 from cmk.utils.http_proxy_config import http_proxy_config_from_user_setting, HTTPProxyConfig
 from cmk.utils.labels import Labels
 from cmk.utils.log import console
@@ -1883,42 +1882,18 @@ def lookup_ip_address(
 #   +----------------------------------------------------------------------+
 
 
-class HostsConfig:
-    def __init__(
-        self,
-        *,
-        hosts: Sequence[HostName],
-        clusters: Sequence[HostName],  # pylint: disable=redefined-outer-name
-        shadow_hosts: Sequence[HostName],  # pylint: disable=redefined-outer-name
-    ) -> None:
-        self.hosts: Final = hosts
-        self.clusters: Final = clusters
-        self.shadow_hosts: Final = shadow_hosts
-
-    def duplicates(self, /, pred: Callable[[HostName], bool]) -> Iterable[HostName]:
-        return (
-            hn
-            for hn, count in Counter(
-                hn
-                for hn in itertools.chain(self.hosts, self.clusters, self.shadow_hosts)
-                if pred(hn)
-            ).items()
-            if count > 1
-        )
-
-    @classmethod
-    def from_config(cls) -> HostsConfig:
-        return cls(
-            hosts=strip_tags(all_hosts),
-            clusters=strip_tags(clusters),
-            shadow_hosts=list(_get_shadow_hosts()),
-        )
+def make_hosts_config() -> Hosts:
+    return Hosts(
+        hosts=strip_tags(all_hosts),
+        clusters=strip_tags(clusters),
+        shadow_hosts=list(_get_shadow_hosts()),
+    )
 
 
 class ConfigCache:
     def __init__(self) -> None:
         super().__init__()
-        self.hosts_config = HostsConfig(hosts=(), clusters=(), shadow_hosts=())
+        self.hosts_config = Hosts(hosts=(), clusters=(), shadow_hosts=())
         self.__enforced_services_table: dict[
             HostName,
             Mapping[
@@ -1948,7 +1923,7 @@ def __init__(self) -> None:
 
     def initialize(self) -> ConfigCache:
         self._initialize_caches()
-        self.hosts_config = HostsConfig.from_config()
+        self.hosts_config = make_hosts_config()
         self._setup_clusters_nodes_cache()
 
         tag_to_group_map = ConfigCache.get_tag_to_group_map()

cmk/base/core_nagios.py

@@ -25,7 +25,7 @@
 from cmk.utils.check_utils import section_name_of
 from cmk.utils.config_path import VersionedConfigPath
 from cmk.utils.exceptions import MKGeneralException
-from cmk.utils.hostaddress import HostAddress, HostName
+from cmk.utils.hostaddress import HostAddress, HostName, Hosts
 from cmk.utils.labels import Labels
 from cmk.utils.licensing.handler import LicensingHandler
 from cmk.utils.log import console
@@ -44,13 +44,7 @@
 import cmk.base.ip_lookup as ip_lookup
 import cmk.base.obsolete_output as out
 import cmk.base.utils
-from cmk.base.config import (
-    ConfigCache,
-    HostgroupName,
-    HostsConfig,
-    ObjectAttributes,
-    ServicegroupName,
-)
+from cmk.base.config import ConfigCache, HostgroupName, ObjectAttributes, ServicegroupName
 from cmk.base.core_config import (
     AbstractServiceID,
     CollectedHostLabels,
@@ -146,10 +140,10 @@ def write(self, x: str) -> None:
 
 
 def _validate_licensing(
-    hosts_config: HostsConfig, licensing_handler: LicensingHandler, licensing_counter: Counter
+    hosts: Hosts, licensing_handler: LicensingHandler, licensing_counter: Counter
 ) -> None:
     if block_effect := licensing_handler.effect_core(
-        licensing_counter["services"], len(hosts_config.shadow_hosts)
+        licensing_counter["services"], len(hosts.shadow_hosts)
     ).block:
         raise MKGeneralException(block_effect.message_raw)
 

cmk/utils/hostaddress.py

@@ -3,11 +3,33 @@
 # This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
 # conditions defined in the file COPYING, which is part of this source code package.
 
+import itertools
+from collections import Counter
+from collections.abc import Callable, Iterable, Sequence
+from dataclasses import dataclass
 from typing import NewType, TypeAlias
 
-__all__ = ["HostAddress", "HostName"]
+__all__ = ["HostAddress", "Hosts", "HostName"]
 
 HostAddress = NewType("HostAddress", str)
 # Let us be honest here, we do not actually make a difference
 # between HostAddress and HostName in our code.
 HostName: TypeAlias = HostAddress
+
+
+@dataclass(frozen=True)
+class Hosts:
+    hosts: Sequence[HostName]
+    clusters: Sequence[HostName]
+    shadow_hosts: Sequence[HostName]
+
+    def duplicates(self, /, pred: Callable[[HostName], bool]) -> Iterable[HostName]:
+        return (
+            hn
+            for hn, count in Counter(
+                hn
+                for hn in itertools.chain(self.hosts, self.clusters, self.shadow_hosts)
+                if pred(hn)
+            ).items()
+            if count > 1
+        )

tests/unit/cmk/base/test_config.py

@@ -42,23 +42,10 @@
 from cmk.base.api.agent_based.checking_classes import CheckPlugin as CheckPluginAPI
 from cmk.base.api.agent_based.register.utils_legacy import LegacyCheckDefinition
 from cmk.base.api.agent_based.type_defs import SNMPSectionPlugin
-from cmk.base.config import ConfigCache, HostsConfig, ip_address_of
+from cmk.base.config import ConfigCache, ip_address_of
 from cmk.base.ip_lookup import AddressFamily
 
 
-def test_duplicate_hosts() -> None:
-    hostnames = (
-        HostName("un"),
-        HostName("deux"),
-        HostName("deux"),
-        HostName("trois"),
-        HostName("trois"),
-        HostName("trois"),
-    )
-    hosts_config = HostsConfig(hosts=hostnames, clusters=(), shadow_hosts=())
-    assert list(hosts_config.duplicates(lambda *args, **kw: True)) == ["deux", "trois"]
-
-
 def test_all_offline_hosts(monkeypatch: MonkeyPatch) -> None:
     ts = Scenario()
     ts.add_host(HostName("blub"), tags={TagGroupID("criticality"): TagID("offline")})

tests/unit/cmk/utils/test_hostaddress.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
+# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
+# conditions defined in the file COPYING, which is part of this source code package.
+
+from cmk.utils.hostaddress import HostName, Hosts
+
+
+def test_duplicate_hosts() -> None:
+    hostnames = (
+        HostName("un"),
+        HostName("deux"),
+        HostName("deux"),
+        HostName("trois"),
+        HostName("trois"),
+        HostName("trois"),
+    )
+    hosts_config = Hosts(hosts=hostnames, clusters=(), shadow_hosts=())
+    assert list(hosts_config.duplicates(lambda *args, **kw: True)) == ["deux", "trois"]