feat: add option to add custom sysctl configs

defaults/main.yml

@@ -13,13 +13,23 @@ kernel_disable_modules:
 
 kernel_blacklist_modules: []
 
-# @var kernel_ipv4_ping_group_range: $ "_unset"
-# @var kernel_ipv4_ping_group_range:example: $ "0 2000000"
+kernel_custom_config: []
+# @var kernel_custom_config:example: >
+# kernel_custom_config:
+#   - file: 90-example
+#     content:
+#       - name: vm.panic_on_oom
+#         value: 0
+#       - name: vm.overcommit_memory
+#         value: 1
+# @end
 
 kernel_namespace_support_enabled: False
 kernel_coredump_enabled: True
 
+# @var kernel_ipv4_ping_group_range: $ "_unset"
+# @var kernel_ipv4_ping_group_range:example: $ "0 2000000"
+kernel_ipv4_forwarding_enabled: False
+
 kernel_ipv6_enabled: False
 kernel_ipv6_forwarding_enabled: False
-
-kernel_ipv4_forwarding_enabled: False

molecule/centos7/converge.yml

@@ -4,5 +4,12 @@
   vars:
     kernel_coredump_enabled: False
     kernel_ipv6_enabled: True
+    kernel_custom_config:
+      - file: 90-example
+        content:
+          - name: vm.panic_on_oom
+            value: 0
+          - name: vm.overcommit_memory
+            value: 1
   roles:
     - role: xoxys.kernel

molecule/centos7/tests/test_default.py

@@ -1,4 +1,5 @@
 import os
+import pytest
 
 import testinfra.utils.ansible_runner
 
@@ -8,7 +9,7 @@ testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
 
 
 def test_sysctl_file(host):
-    sysctl = host.file("/etc/sysctl.d/local.conf")
+    sysctl = host.file("/etc/sysctl.d/99-local.conf")
 
     assert sysctl.exists
     assert sysctl.user == "root"
@@ -16,6 +17,18 @@ def test_sysctl_file(host):
     assert sysctl.mode == 0o644
 
 
+@pytest.mark.parametrize(
+    "name,value", [
+        ("net.ipv4.ip_forward", 0),
+        ("net.ipv6.conf.all.forwarding", 0),
+        ("vm.panic_on_oom", 0),
+        ("vm.overcommit_memory", 1),
+    ]
+)
+def test_sysctl_values(host, name, value):
+    assert host.sysctl(name) == value
+
+
 def test_modprobe_file(host):
     modprobe = host.file("/etc/modprobe.d/custom.conf")
 
@@ -28,6 +41,6 @@ def test_modprobe_file(host):
 
 
 def test_coredump_config(host):
-    assert host.file("/etc/sysctl.d/dump.conf").exists
+    assert host.file("/etc/sysctl.d/99-dump.conf").exists
     assert host.file("/etc/security/limits.d/dump.conf").exists
     assert host.file("/etc/profile.d/dump.sh").exists

molecule/default

@@ -1 +1 @@
-rocky8
+rocky9

molecule/rocky9/converge.yml

@@ -4,5 +4,12 @@
   vars:
     kernel_coredump_enabled: False
     kernel_ipv6_enabled: True
+    kernel_custom_config:
+      - file: 90-example
+        content:
+          - name: vm.panic_on_oom
+            value: 0
+          - name: vm.overcommit_memory
+            value: 1
   roles:
     - role: xoxys.kernel

molecule/rocky9/tests/test_default.py

@@ -9,7 +9,7 @@ testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
 
 
 def test_sysctl_file(host):
-    sysctl = host.file("/etc/sysctl.d/local.conf")
+    sysctl = host.file("/etc/sysctl.d/99-local.conf")
 
     assert sysctl.exists
     assert sysctl.user == "root"
@@ -21,6 +21,8 @@ def test_sysctl_file(host):
     "name,value", [
         ("net.ipv4.ip_forward", 0),
         ("net.ipv6.conf.all.forwarding", 0),
+        ("vm.panic_on_oom", 0),
+        ("vm.overcommit_memory", 1),
     ]
 )
 def test_sysctl_values(host, name, value):
@@ -39,6 +41,6 @@ def test_modprobe_file(host):
 
 
 def test_coredump_config(host):
-    assert host.file("/etc/sysctl.d/dump.conf").exists
+    assert host.file("/etc/sysctl.d/99-dump.conf").exists
     assert host.file("/etc/security/limits.d/dump.conf").exists
     assert host.file("/etc/profile.d/dump.sh").exists

tasks/coredump.yml

@@ -2,8 +2,8 @@
 - block:
     - name: Disable core dump for setuid programs
       template:
-        src: etc/sysctl.d/dump.conf.j2
-        dest: /etc/sysctl.d/dump.conf
+        src: etc/sysctl.d/99-dump.conf.j2
+        dest: /etc/sysctl.d/99-dump.conf
         owner: root
         group: root
         mode: 0644

tasks/kernel.yml

@@ -1,14 +1,26 @@
 ---
 - block:
-    - name: Set kernel hardening parameters
+    - name: Set default kernel hardening parameters
       template:
-        src: etc/sysctl.d/local.conf.j2
-        dest: /etc/sysctl.d/local.conf
+        src: etc/sysctl.d/99-local.conf.j2
+        dest: /etc/sysctl.d/99-local.conf
         owner: root
         group: root
         mode: 0644
       notify: __kernel_reload
 
+    - name: Deploy custom kernel configurations
+      template:
+        src: etc/sysctl.d/xx-custom.conf.j2
+        dest: "/etc/sysctl.d/{{ item.file }}.conf"
+        owner: root
+        group: root
+        mode: 0644
+      loop: "{{ kernel_custom_config }}"
+      loop_control:
+        label: "{{ item.file }}"
+      notify: __kernel_reload
+
     - name: Deploy custom modprobe
       template:
         src: etc/modprobe.d/custom.conf.j2

templates/etc/sysctl.d/99-dump.conf.j2

@@ -1,3 +1,4 @@
+#jinja2: lstrip_blocks: True
 {{ ansible_managed | comment }}
 # Controls whether core dumps will append the PID to the core filename
 kernel.core_uses_pid = 1

templates/etc/sysctl.d/xx-custom.conf.j2

@@ -0,0 +1,5 @@
+#jinja2: lstrip_blocks: True
+{{ ansible_managed | comment }}
+{% for option in item.content %}
+{{ option.name }} = {{ option.value }}
+{% endfor %}