Update (& fix) dockerd role.

roles/dockerd/files/override.conf

@@ -0,0 +1,3 @@
+[Service]
+Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_NET=slirp4netns"
+Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=slirp4netns"

roles/dockerd/tasks/main.yml

@@ -1,6 +1,7 @@
 - name: Make sure required packages are installed
   apt:
     name:
+      - dbus-user-session
       - docker.io
       - docker-compose
       - rootlesskit
@@ -8,23 +9,26 @@
       - uidmap
   become: true
 
-- name: Make sure system-wide Docker daemon is stopped & disabled
+- name: Make sure system-wide Docker daemon & socket are stopped & disabled
   service:
-    name: docker
+    name: "{{ item }}"
     state: stopped
     enabled: false
+  loop:
+    - docker
+    - docker.socket
   become: true
 
-- name: Make sure system-wide Docker socket is stopped & disabled
-  service:
-    name: docker.socket
-    state: stopped
-    enabled: false
-  become: true
+- name: Get docker user service status
+  stat:
+    path: "{{ ansible_env['HOME'] }}/.config/systemd/user/docker.service"
+  register: dockerd_user_service_file_result
 
 - name: Run dockerd-rootless-setuptool.sh script
   command:
     cmd: /usr/share/docker.io/contrib/dockerd-rootless-setuptool.sh install
+  # Don't run install script everytime
+  when: not dockerd_user_service_file_result.stat.exists
 
 - name: Make sure /usr/share/docker.io/contrib is in PATH variable
   lineinfile:
@@ -43,21 +47,35 @@
     cmd: "loginctl enable-linger {{ ansible_env['USER'] }}"
   become: true
 
-- name: "Create directory {{ ansible_env['HOME'] }}/.config/systemd/user/docker.service.d to override environment variables"
+- name: "Create directory {{ ansible_env['HOME'] }}/.config/systemd/user/docker.service.d"
   file:
     path: "{{ ansible_env['HOME'] }}/.config/systemd/user/docker.service.d"
     state: directory
 
-- name: Add environment variables to Docker user service to use slirp4netns RootlessKit port driver, which enables source IP propagation
+# Set port driver to slirp4netns to enable source IP propagation, which is required for coturn to work.
+- name: "Copy systemd service override.conf to {{ ansible_env['HOME'] }}/.config/systemd/user/docker.service.d/override.conf"
   copy:
+    src: "{{ role_path }}/files/override.conf"
     dest: "{{ ansible_env['HOME'] }}/.config/systemd/user/docker.service.d/override.conf"
-    content: |
-      [Service]
-      Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_NET=slirp4netns"
-      Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=slirp4netns"
+  register: dockerd_copy_override_conf_result
+
+- name: Edit some sysctl entries for Redis & Syncthing
+  sysctl:
+    name: "{{ item.key }}"
+    value: "{{ item.value }}"
+  loop:
+    - key: vm.overcommit_memory
+      value: 1
+    - key: net.core.wmem_max
+      value: 2500000
+    - key: net.core.rmem_max
+      value: 2500000
+  become: true
 
 - name: Start/restart & enable Docker user service
   service:
     name: docker
-    state: restarted
+    scope: user
+    # Restart only if config file(s) changed
+    state: "{{ (dockerd_copy_override_conf_result.changed) | ternary('restarted', 'started') }}"
     enabled: true