fix(k3s): add configuration parameter for disabling cgroup mount to avoid "unable to apply cgroup configuration" (testcontainers#592)

relates to testcontainers#591

Author: alexanderankin

modules/k3s/testcontainers/k3s/__init__.py

@@ -11,6 +11,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import logging
+
 from testcontainers.core.config import testcontainers_config
 from testcontainers.core.container import DockerContainer
 from testcontainers.core.waiting_utils import wait_for_logs
@@ -37,13 +39,16 @@ class K3SContainer(DockerContainer):
     KUBE_SECURE_PORT = 6443
     RANCHER_WEBHOOK_PORT = 8443
 
-    def __init__(self, image="rancher/k3s:latest", **kwargs) -> None:
+    def __init__(self, image="rancher/k3s:latest", enable_cgroup_mount=True, **kwargs) -> None:
         super().__init__(image, **kwargs)
         self.with_exposed_ports(self.KUBE_SECURE_PORT, self.RANCHER_WEBHOOK_PORT)
         self.with_env("K3S_URL", f"https://{self.get_container_host_ip()}:{self.KUBE_SECURE_PORT}")
         self.with_command("server --disable traefik --tls-san=" + self.get_container_host_ip())
         self.with_kwargs(privileged=True, tmpfs={"/run": "", "/var/run": ""})
-        self.with_volume_mapping("/sys/fs/cgroup", "/sys/fs/cgroup", "rw")
+        if enable_cgroup_mount:
+            self.with_volume_mapping("/sys/fs/cgroup", "/sys/fs/cgroup", "rw")
+        else:
+            logging.warning("'enable_cgroup_mount' is experimental, see testcontainers/testcontainers-python#591)")
 
     def _connect(self) -> None:
         wait_for_logs(self, predicate="Node controller sync successful", timeout=testcontainers_config.timeout)