refactor: replace docker stack with k3s/containerd

ansible/roles/base/tasks/hardware.yml

@@ -2,8 +2,11 @@
 
 - name: Deploy raspberry config
   template:
-    src: config.txt
-    dest: /boot/config.txt
+    src: "{{ item }}"
+    dest: /boot/{{ item }}
+  with_items:
+    - cmdline.txt
+    - config.txt
   notify: reboot
 
 - name: Set pi user in groups

ansible/roles/base/templates/cmdline.txt

@@ -0,0 +1 @@
+console=serial0,115200 console=tty1 root=PARTUUID=424e930f-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory

ansible/roles/k3s/defaults/main.yml

@@ -0,0 +1,3 @@
+---
+k3s_version: v1.19.15%2Bk3s2
+k3s_url: https://github.com/k3s-io/k3s/releases/download/{{ k3s_version }}/k3s-{{ arch | default('armhf') }}

ansible/roles/k3s/handlers/main.yml

@@ -0,0 +1,7 @@
+---
+- name: restart k3s
+  systemd:
+    name: k3s
+    enabled: yes
+    daemon_reload: yes
+    state: restarted

ansible/roles/k3s/tasks/containerd.yml

@@ -0,0 +1,18 @@
+- name: Add apt key
+  apt_key:
+    url:  https://download.docker.com/linux/debian/gpg
+
+- name: Add docker-ce repository
+  apt_repository:
+    repo: deb [arch={{ arch | default('armhf') }}] https://download.docker.com/linux/debian {{ ansible_distribution_release }} stable
+    state: present
+    filename: 'docker'
+
+
+- meta: flush_handlers
+
+- name: Install containerd.io
+  apt:
+    name:
+      - containerd.io
+    state: present

ansible/roles/k3s/tasks/k3s.yml

@@ -0,0 +1,20 @@
+---
+- name: Download k3s binary
+  get_url:
+    url: "{{ k3s_url}}"
+    dest: "/usr/local/bin/k3s"
+    mode: 0755
+    force: yes
+
+- name: Copy systemd script
+  template:
+    src: k3s.service.j2
+    dest: /etc/systemd/system/k3s.service
+  notify: restart k3s
+
+- name: Ensure k3s service is started
+  systemd:
+    name: k3s
+    enabled: yes
+    daemon_reload: yes
+    state: started

ansible/roles/k3s/tasks/main.yaml

@@ -0,0 +1,3 @@
+---
+- include_tasks: containerd.yml
+- include_tasks: k3s.yml

ansible/roles/k3s/templates/k3s.service.j2

@@ -0,0 +1,29 @@
+[Unit]
+Description=Lightweight Kubernetes
+Documentation=https://k3s.io
+Wants=network-online.target,containerd
+After=network-online.target,containerd
+
+[Install]
+WantedBy=multi-user.target
+
+[Service]
+Type=notify
+EnvironmentFile=-/etc/default/%N
+EnvironmentFile=-/etc/sysconfig/%N
+EnvironmentFile=-/etc/k3s/conf.env
+KillMode=process
+Delegate=yes
+# Having non-zero Limit*s causes performance problems due to accounting overhead
+# in the kernel. We recommend using cgroups to do container-local accounting.
+LimitNOFILE=1048576
+LimitNPROC=infinity
+LimitCORE=infinity
+TasksMax=infinity
+TimeoutStartSec=0
+Restart=always
+RestartSec=5s
+ExecStartPre=/bin/sh -xc '! /usr/bin/systemctl is-enabled --quiet nm-cloud-setup.service'
+ExecStartPre=-/sbin/modprobe br_netfilter
+ExecStartPre=-/sbin/modprobe overlay
+ExecStart=/usr/local/bin/k3s server

ansible/site.yml

@@ -9,7 +9,7 @@
   become: yes
   roles:
     - { role: rabbitmq, tags: [rabbitmq] }
-    - { role: docker, tags: [docker] }
+    - { role: k3s, tags: [k3s] }
     - { role: microservices, tags: [microservices, ms] }