GRM-143: fix: disable IPv6 in rootless Docker daemon on runners

ansible/roles/gitea-runner/tasks/rootless_docker.yml

@@ -97,6 +97,39 @@
   changed_when: true
   when: docker_rootless_setup
 
+- name: Ensure Docker config directory exists
+  ansible.builtin.file:
+    path: "{{ gitea_runner_home }}/.config/docker"
+    state: directory
+    mode: "0755"
+    owner: "{{ gitea_runner_service_user }}"
+    group: "{{ gitea_runner_service_user }}"
+  when: docker_rootless_setup
+
+- name: Configure rootless Docker to disable IPv6
+  ansible.builtin.copy:
+    dest: "{{ gitea_runner_home }}/.config/docker/daemon.json"
+    content: |
+      {
+        "ipv6": false
+      }
+    mode: "0644"
+    owner: "{{ gitea_runner_service_user }}"
+    group: "{{ gitea_runner_service_user }}"
+  register: docker_ipv6_config
+  when: docker_rootless_setup
+
+- name: Restart rootless Docker if config changed
+  ansible.builtin.command: systemctl --user restart docker
+  become: true
+  become_user: "{{ gitea_runner_service_user }}"
+  environment:
+    XDG_RUNTIME_DIR: "/run/user/{{ gitea_runner_uid }}"
+  changed_when: true
+  when:
+    - docker_rootless_setup
+    - docker_ipv6_config is changed
+
 - name: Wait for rootless Docker daemon to be ready
   ansible.builtin.command: docker version
   become: true