sysctl_additional (#9351)

roles/kubernetes/preinstall/tasks/0080-system-configurations.yml

@@ -127,3 +127,12 @@
     state: present
     params: 'numdummies=0'
   when: enable_nodelocaldns
+
+- name: Set additional sysctl variables
+  sysctl:
+    sysctl_file: "{{ sysctl_file_path }}"
+    name: "{{ item.name }}"
+    value: "{{ item.value }}"
+    state: present
+    reload: yes
+  with_items: "{{ additional_sysctl }}"

roles/kubespray-defaults/defaults/main.yaml

@@ -487,6 +487,12 @@ kubelet_rotate_server_certificates: false
 # If set to true, kubelet errors if any of kernel tunables is different than kubelet defaults
 kubelet_protect_kernel_defaults: true
 
+# Set additional sysctl variables to modify Linux kernel variables, for example:
+# additional_sysctl:
+#  - { name: kernel.pid_max, value: 131072 }
+#
+additional_sysctl: []
+
 ## List of key=value pairs that describe feature gates for
 ## the k8s cluster.
 kube_feature_gates: []