Add the installation of cadvisor.

README.md

@@ -1,7 +1,9 @@
 Role Name
 =========
 
-A role that installs and configures Docker and eventually Docker Swarm, <https://docker.com>
+A role that installs and configures Docker and eventually prepares Docker Swarm, <https://docker.com>.
+The Docker Swarm nodes configuration is managed by a separate role.
+cAdvisor is also installed, as standalone package and not as container. The standalone package does not require a local Prometheus instance
 
 Role Variables
 --------------

defaults/main.yml

@@ -44,6 +44,14 @@ docker_prometheus_metrics: true
 docker_prometheus_host: 127.0.0.1
 docker_prometheus_metrics_port: 9323
 
+# cAdvisor
+docker_swarm_cluster_cadvisor_install: true
+docker_swarm_cluster_cadvisor_deb_pkg: true
+docker_swarm_cluster_cadvisor_docker_endpoint: "unix:///var/run/docker.sock"
+docker_swarm_cluster_cadvisor_port: 4194
+docker_swarm_cluster_cadvisor_github_url: "https://github.com/google/cadvisor/releases/download/v0.47.0/cadvisor-v0.47.0-linux-amd64"
+docker_swarm_cluster_cadvisor_binary_path: /usr/local/bin/cadvisor
+
 # Usage:
 # node.labels.<key_name>==<label_value>
 # node.labels.<key_name>!=<label_value>

tasks/cadvisor.yml

@@ -0,0 +1,55 @@
+---
+- name: Manage the installation of cAdvisor deb package
+  when: docker_swarm_cluster_cadvisor_deb_pkg
+  tags: ['cadvisor', 'docker_cadvisor', 'docker_swarm', 'docker']
+  block:
+    - name: Install the cadvisor package
+      ansible.builtin.apt:
+        pkg: cadvisor
+        state: present
+        cache_valid_time: 1800
+
+- name: Manage the installation of cAdvisor Linux binary from GitHub
+  when: not docker_swarm_cluster_cadvisor_deb_pkg
+  tags: ['cadvisor', 'docker_cadvisor', 'docker_swarm', 'docker']
+  block:
+    - name: Download the cAdvisor executable from GitHub
+      ansible.builtin.get_url:
+        url: "{{ docker_swarm_cluster_cadvisor_github_url }}"
+        dest: "{{ docker_swarm_cluster_cadvisor_binary_path }}"
+        owner: root
+        group: root
+        mode: 0755
+
+    - name: Install the cAdvisor systemd unit
+      ansible.builtin.template:
+        src: cadvisor.systemd.j2
+        dest: /lib/systemd/system/cadvisor.service
+        owner: root
+        group: root
+        mode: 0644
+      notify: Restart cadvisor
+      register: systemd_reload
+
+    - name: Reload the systemd unit
+      ansible.builtin.systemd:
+        daemon_reload: true
+      when: systemd_reload is changed
+
+- name: Manage the cAdvisor service
+  tags: ['cadvisor', 'docker_cadvisor', 'docker_swarm', 'docker']
+  block:
+    - name: Install the cadvisor default
+      ansible.builtin.template:
+        src: cadvisor.default.j2
+        dest: /etc/default/cadvisor
+        mode: 0600
+        owner: root
+        group: root
+      notify: Restart cadvisor
+
+    - name: Ensure that the cAdvisor service is up and running
+      ansible.builtin.service:
+        name: cadvisor
+        state: started
+        enabled: true

tasks/main.yml

@@ -9,6 +9,9 @@
   when: ansible_distribution_file_variety == "RedHat"
 
 - import_tasks: docker_setup.yml
+- name: Import the cAdvisor tasks
+  ansible.builtin.import_tasks: cadvisor.yml
+  when: docker_swarm_cluster_cadvisor_install
 
 - import_tasks: swarm_mgr.yml
   when: docker_swarm

templates/cadvisor.default.j2

@@ -0,0 +1,44 @@
+# config options for cadvisor(1)
+#
+
+# Docker endpoint to connect to
+# Default: unix:///var/run/docker.sock
+CADVISOR_DOCKER_ENDPOINT="{{ docker_swarm_cluster_cadvisor_docker_endpoint }}"
+
+# Port to listen on
+# Default: 8080
+# kubernetes expects it on port 4194
+CADVISOR_PORT="{{ docker_swarm_cluster_cadvisor_port }}"
+
+# Storage driver
+# Default: none/blank
+#
+# Available Options:
+#  - [none]
+#  - bigquery
+#  - influxdb
+CADVISOR_STORAGE_DRIVER=""
+
+# Storage driver host
+# Default: localhost:8086"
+CADVISOR_STORAGE_DRIVER_HOST="localhost:8086"
+
+# Storage driver password
+# Default: root
+CADVISOR_STORAGE_DRIVER_PASSWORD="root"
+
+# Storage driver secure connection
+# Default: false
+CADVISOR_STORAGE_DRIVER_SECURE="false"
+
+# Storage driver user
+# Default: root
+CADVISOR_STORAGE_DRIVER_USER="root"
+
+# Log to stderr ("true" logs to journal on systemd
+# and to "/var/log/cadvisor.log" on SysV)
+# Default: false
+CADVISOR_LOG_TO_STDERR="true"
+
+# Other options:
+#DAEMON_ARGS=""

templates/cadvisor.systemd.j2

@@ -0,0 +1,20 @@
+[Unit]
+Description=cAdvisor
+Documentation=man:cadvisor
+Documentation=https://github.com/google/cadvisor
+
+[Service]
+EnvironmentFile=/etc/default/cadvisor
+ExecStart={{ docker_swarm_cluster_cadvisor_binary_path }} \
+    --docker=${CADVISOR_DOCKER_ENDPOINT} \
+    --port=${CADVISOR_PORT} \
+    --storage_driver=${CADVISOR_STORAGE_DRIVER} \
+    --storage_driver_host=${CADVISOR_STORAGE_DRIVER_HOST} \
+    --storage_driver_password=${CADVISOR_STORAGE_DRIVER_PASSWORD} \
+    --storage_driver_secure=${CADVISOR_STORAGE_DRIVER_SECURE} \
+    --storage_driver_user=${CADVISOR_STORAGE_DRIVER_USER} \
+    --logtostderr=${CADVISOR_LOG_TO_STDERR} \
+    ${DAEMON_ARGS}
+
+[Install]
+WantedBy=multi-user.target