tests: Add containerd cfg dir marker

One of the tests uses a custom containerd base dir. We'll add a
marker so that the registry mirror settings can be applied to that
containerd folder.

tests/integration/tests/conftest.py

@@ -139,6 +139,7 @@ def pytest_configure(config):
         "bootstrap_config: Provide a custom bootstrap config to the bootstrapping node.\n"
         "disable_k8s_bootstrapping: By default, the first k8s node is bootstrapped. This marker disables that.\n"
         "no_setup: No setup steps (pushing snap, bootstrapping etc.) are performed on any node for this test.\n"
+        "containerd_cfgdir: The instance containerd config directory, defaults to /etc/containerd."
         "network_type: Specify network type to use for the infrastructure (IPv4, Dualstack or IPv6).\n"
         "etcd_count: Mark a test to specify how many etcd instance nodes need to be created (None by default)\n"
         "node_count: Mark a test to specify how many instance nodes need to be created\n"
@@ -192,6 +193,15 @@ def network_type(request) -> Union[str, None]:
     return network_type
 
 
+@pytest.fixture(scope="function")
+def containerd_cfgdir(request) -> str:
+    marker = request.node.get_closest_marker("containerd_cfgdir")
+    if not marker:
+        return "/etc/containerd"
+    cfgdir, *_ = marker.args
+    return cfgdir
+
+
 @pytest.fixture(scope="function")
 def instances(
     h: harness.Harness,
@@ -200,6 +210,7 @@ def instances(
     tmp_path: Path,
     disable_k8s_bootstrapping: bool,
     no_setup: bool,
+    containerd_cfgdir: str,
     bootstrap_config: Union[str, None],
     request,
     network_type: str,
@@ -241,7 +252,7 @@ def instances(
             util.setup_k8s_snap(instance, tmp_path, snap)
 
             if config.USE_LOCAL_MIRROR:
-                registry.apply_configuration(instance)
+                registry.apply_configuration(instance, containerd_cfgdir)
 
     if not disable_k8s_bootstrapping and not no_setup:
         first_node, *_ = instances

tests/integration/tests/test_cleanup.py

@@ -42,6 +42,7 @@ def test_node_cleanup(instances: List[harness.Instance], tmp_path):
 
 @pytest.mark.node_count(2)
 @pytest.mark.disable_k8s_bootstrapping()
+@pytest.mark.containerd_cfgdir("/home/ubuntu/etc/containerd")
 @pytest.mark.tags(tags.NIGHTLY)
 def test_node_cleanup_new_containerd_path(instances: List[harness.Instance]):
     main = instances[0]
@@ -70,12 +71,10 @@ def test_node_cleanup_new_containerd_path(instances: List[harness.Instance]):
         for p in CONTAINERD_PATHS
     ]
 
-    # We expect containerd to use our custom paths instead of the default ones.
-    # However, the test fixture places registry configuration in /etc/containerd
-    # and /run/containerd gets created but isn't actually used (requires further
+    # /run/containerd gets created but isn't actually used (requires further
     # investigation).
     exp_missing_paths = [
-        "/etc/containerd/config.toml",
+        "/etc/containerd",
         "/run/containerd/containerd.sock",
         "/var/lib/containerd",
     ]

tests/integration/tests/test_util/registry.py

@@ -2,6 +2,7 @@
 # Copyright 2024 Canonical, Ltd.
 #
 import logging
+import os
 from pathlib import Path
 from string import Template
 from typing import List, Optional
@@ -165,21 +166,22 @@ def ip(self) -> str:
         return self._ip
 
     # Configure the specified instance to use this registry mirror.
-    def apply_configuration(self, instance):
+    def apply_configuration(self, instance, containerd_basedir="/etc/containerd"):
         for mirror in self.mirrors:
             substitutes = {
                 "IP": self.ip,
                 "PORT": mirror.port,
             }
 
-            instance.exec(["mkdir", "-p", f"/etc/containerd/hosts.d/{mirror.name}"])
+            mirror_dir = os.path.join(containerd_basedir, "hosts.d", mirror.name)
+            instance.exec(["mkdir", "-p", mirror_dir])
 
             with open(config.REGISTRY_DIR / "hosts.toml", "r") as registry_template:
                 src = Template(registry_template.read())
                 instance.exec(
                     [
                         "dd",
-                        f"of=/etc/containerd/hosts.d/{mirror.name}/hosts.toml",
+                        f"of={mirror_dir}/hosts.toml",
                     ],
                     input=str.encode(src.substitute(substitutes)),
                 )