firewall: don't put invalid rules in /etc/iptables/

1 files changed, 45 insertions, 0 deletions

diff --git a/roles/firewall/tasks/file.yml b/roles/firewall/tasks/file.yml
new file mode 100644
index 0000000..a703d3b
--- /dev/null
+++ b/roles/firewall/tasks/file.yml
@@ -0,0 +1,45 @@
+- name: Create a temporary file
+  ansible.builtin.tempfile:
+  register: rules_file
+
+- name: Configure rules in a temporary file
+  become: true
+  ansible.builtin.template:
+    src: '{{ item.src }}'
+    dest: '{{ rules_file.path }}'
+    owner: root
+    group: root
+    mode: '640'
+
+- name: Print temporary file path
+  ansible.builtin.debug:
+    msg: 'Temporary rules file: {{ rules_file.path }}'
+
+# If I simply restart the netfilter-persistent service, it happily restarts,
+# effectively ignoring errors in files. That way the operator doesn't get
+# feedback if the rules file is malformed.
+- name: Check that the rules are valid
+  become: true
+  ansible.builtin.command:
+    argv:
+      - '/usr/sbin/{{ item.tool }}-restore'
+      - --test
+      - '{{ rules_file.path }}'
+  changed_when: false
+
+- name: Copy rules to /etc/iptables
+  become: true
+  ansible.builtin.copy:
+    remote_src: true
+    src: '{{ rules_file.path }}'
+    dest: '{{ item.dest }}'
+    owner: root
+    group: root
+    mode: '640'
+  notify: Reboot
+
+- name: Remove temporary file
+  become: true
+  ansible.builtin.file:
+    path: '{{ rules_file.path }}'
+    state: absent