Fix docker-compose package conflict and alpine firewall handler (#22)

- Docker role: replace docker-compose with docker-compose-plugin (v2).
  The old docker-compose package conflicts with docker-compose-plugin
  already installed on helsinki-a. Also removes the conflicting package
  if present.

- firewall_alpine handler: use ansible.builtin.shell instead of
  ansible.builtin.command for iptables-restore, since the redirect
  operator (<) requires a shell.

ansible/roles/docker/tasks/main.yml

@@ -5,10 +5,16 @@
   ansible.builtin.apt:
     name:
       - docker.io
-      - docker-compose
+      - docker-compose-plugin
     state: present
   when: ansible_facts["os_family"] == "Debian"
 
+- name: Remove conflicting docker-compose package (Debian)
+  ansible.builtin.apt:
+    name: docker-compose
+    state: absent
+  when: ansible_facts["os_family"] == "Debian"
+
 - name: Install Docker (Alpine)
   community.general.apk:
     name:

ansible/roles/firewall_alpine/handlers/main.yml

@@ -1,6 +1,6 @@
 ---
 - name: Restore iptables
-  ansible.builtin.command: iptables-restore < /etc/iptables/rules-save
+  ansible.builtin.shell: iptables-restore < /etc/iptables/rules-save
   changed_when: true
 
 - name: Restart fail2ban