Add Docker container support

README.md

@@ -14,22 +14,30 @@ Design goals are to have a minimal memory footprint with a plugin system so that
 
 ## Requirements
 
-### Operating systems
-This role will work on the following operating systems:
+### Supported systems
+This role supports the following systems:
 
  * Red Hat
  * Debian
  * Ubuntu
+ * Docker container
  * Windows (Best effort)
  * (Open)Suse
 
-So, you'll need one of those operating systems.. :-)
-Please sent Pull Requests or suggestions when you want to use this role for other Operating systems.
+So, you'll need one of those systems.. :-)
+Please sent Pull Requests or suggestions when you want to use this role for other systems.
 
 ### InfluxDB
 
 You'll need an InfluxDB instance running somewhere on your network.
 
+### Docker
+
+Docker needs to be installed on the target host. I can recommend these roles to install Docker:
+
+* [jgeusebroek.docker](https://galaxy.ansible.com/jgeusebroek/docker)
+* [geerlingguy.docker](https://galaxy.ansible.com/geerlingguy/docker)
+
 ## Upgrade
 ### 0.7.0
 
@@ -60,7 +68,14 @@ The following parameters can be set for the Telegraf agent:
 * `telegraf_agent_logfile`: The agent logfile name. Default: '' (means to log to stdout) (since v1.1)
 * `telegraf_agent_omit_hostname`: Do no set the "host" tag in the agent. Default: `False` (since v1.1)
 
-Full agent settings reference: https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#agent-configuration
+Docker specific role variables:
+
+* `telegraf_agent_docker`: Install Telegraf as a docker container. Default: `False`
+* `telegraf_agent_docker_name`: Name of the docker container. Default: `telegraf`
+* `telegraf_agent_docker_network_mode`: Networking mode of the docker container. Default: `bridge`
+* `telegraf_agent_docker_restart_policy`: Docker container restart policy. Default: `unless-stopped`
+
+Full agent settings reference: [https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#agent-configuration](https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#agent-configuration).
 
 You can set tags for the host running telegraf:
 
@@ -84,6 +99,55 @@ The config will be printed line by line into the configuration, so you could als
 		- # Print an documentation line
 
 and it will be printed in the configuration file.
+	
+### Docker specifics
+
+#### Docker image
+
+The official [Influxdata Telegraf image](https://hub.docker.com/_/telegraf) is used. 	`telegraf_agent_version` will translate to the image tag.
+
+#### Docker mounts
+
+Please note that the Docker container bind mounts basicly your whole system (read-only) to monitor the Docker Engine Host from within the container. To be precise:
+
+	- /etc/telegraf:/etc/telegraf:ro
+	- /:/hostfs:ro
+	- /etc:/hostfs/etc:ro
+	- /proc:/hostfs/proc:ro
+	- /sys:/hostfs/sys:ro
+	- /var/run:/var/run:ro
+
+More information: [https://github.com/influxdata/telegraf/blob/master/docs/FAQ.md](https://github.com/influxdata/telegraf/blob/master/docs/FAQ.md).
+
+#### Example Docker configuration
+
+	telegraf_agent_docker: True
+	# Force host networking mode, so Docker Engine Host traffic metrics can be gathered.
+	telegraf_agent_docker_network_mode: host
+	# Force a specific image tag.
+	telegraf_agent_version: 1.9.2-alpine
+
+	telegraf_plugins_default:
+	  - plugin: cpu
+	    config:
+	      - percpu = "true"
+	  - plugin: disk
+	    tags:
+	      - diskmetrics = "true"
+	    tagpass:
+	      - fstype = [ "ext4", "xfs" ]
+	    tagdrop:
+	      - path = [ "/etc", "/etc/telegraf", "/etc/hostname", "/etc/hosts", "/etc/resolv.conf" ]
+	  - plugin: io
+	  - plugin: mem
+	  - plugin: system
+	  - plugin: swap
+	  - plugin: netstat
+	  - plugin: processes
+	  - plugin: docker
+	    config:
+	      - endpoint = "unix:///var/run/docker.sock"
+	      - timeout = "5s"
 
 ## Windows specific Variables
 
@@ -177,6 +241,7 @@ The following have contributed to this Ansible role:
  * Romain BUREAU
  * TheCodeAssassin
  * tjend
+ * Jeroen Geusebroek
 
 Thank you all!
 

defaults/main.yml

@@ -14,6 +14,12 @@ telegraf_agent_flush_jitter: 0
 telegraf_agent_aws_tags: False
 telegraf_agent_aws_tags_prefix: ""
 
+# Docker specific settings
+telegraf_agent_docker: False
+telegraf_agent_docker_name: telegraf
+telegraf_agent_docker_network_mode: bridge
+telegraf_agent_docker_restart_policy: unless-stopped
+
 # v0.13 settings (not sure if supported in older version):
 telegraf_agent_collection_jitter: 0
 telegraf_agent_metric_batch_size: 1000

handlers/main.yml

@@ -6,8 +6,14 @@
     name: telegraf
     state: restarted
     enabled: yes
+  when: not telegraf_agent_docker
   become: yes
 
+- name: "Restart Telegraf container"
+  docker_container:
+    name: "{{ telegraf_agent_docker_name }}"
+    restart: True
+
 - name: "Restart Windows Telegraf"
   win_service:
     name: Telegraf

tasks/Debian.yml

@@ -45,7 +45,7 @@
   when:
     - ansible_lsb is not defined or ansible_lsb.codename is not defined
 
-- name: "Debian | Install telegraf package"
+- name: "Debian | Install Telegraf package"
   apt:
     name: "{{ telegraf_agent_package }}"
     state: "{{ telegraf_agent_package_state }}"

tasks/RedHat.yml

@@ -20,7 +20,7 @@
     gpgcheck: yes
     gpgkey: https://repos.influxdata.com/influxdb.key
 
-- name: "RedHat | Install telegraf package"
+- name: "RedHat | Install Telegraf package"
   package:
     name: "{{ telegraf_agent_package }}"
     state: "{{ telegraf_agent_package_state }}"

tasks/Suse.yml

@@ -1,11 +1,11 @@
 ---
 
-- name: "Suse | Adding telegraf group"
+- name: "Suse | Adding Telegraf group"
   group:
     name: telegraf
     state: present
 
-- name: "Suse | Adding telegraf user"
+- name: "Suse | Adding Telegraf user"
   user:
     name: telegraf
     group: telegraf

tasks/configure_linux.yml

@@ -25,7 +25,9 @@
   become: yes
   when:
     - telegraf_agent_version is version_compare('0.10.0', '<')
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Copy the template for versions >= 0.10.0"
   template:
@@ -37,7 +39,9 @@
   become: yes
   when:
     - telegraf_agent_version is version_compare('0.10.0', '>=')
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Check if extra plugins directory exists in case of exclusive"
   stat:
@@ -54,7 +58,9 @@
     - telegraf_plugins_extra_exclusive
     - telegraf_directory.stat.exists
   become: yes
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Create telegraf extra plugin path"
   file:
@@ -67,7 +73,9 @@
     - telegraf_plugins_extra_exclusive
     - telegraf_directory.stat.exists
   become: yes
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Copy telegraf extra plugins"
   template:
@@ -84,7 +92,9 @@
     - telegraf_plugins_extra is iterable
     - item.value.state|default('present') != 'absent'
   become: yes
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Remove telegraf extra plugins"
   file:
@@ -98,7 +108,9 @@
     - telegraf_plugins_extra is iterable
     - item.value.state|default('present') == 'absent'
   become: yes
-  notify: "Restart Telegraf"
+  notify:
+    - Restart Telegraf
+    - Restart Telegraf container
 
 - name: "Force restart service after reread config"
   meta: flush_handlers
@@ -109,3 +121,4 @@
     state: started
     enabled: yes
   become: yes
+  when: not telegraf_agent_docker

tasks/docker.yml

@@ -0,0 +1,55 @@
+- name: Adding Telegraf group
+  group:
+    name: telegraf
+    state: present
+    gid: 995
+
+- name: Adding Telegraf user
+  user:
+    name: telegraf
+    group: telegraf
+    state: present
+    create_home: False
+    home: /etc/telegraf
+    uid: 998
+    system: True
+  become: yes
+
+- name: Create /etc/telegraf (home) directory
+  file:
+    path: /etc/telegraf
+    owner: telegraf
+    group: telegraf
+    mode: 0750
+    state: directory
+  become: yes
+
+- name: Create /etc/telegraf.d directory
+  file:
+    path: /etc/telegraf/telegraf.d
+    owner: telegraf
+    group: telegraf
+    mode: 0750
+    state: directory
+  become: yes
+
+- name: Ensure Telegraf Docker container is running
+  docker_container:
+    name: "{{ telegraf_agent_docker_name }}"
+    image: "telegraf:{{ telegraf_agent_version }}"
+    state: started
+    restart_policy: "{{ telegraf_agent_docker_restart_policy }}"
+    command: -config /etc/telegraf/telegraf.conf -config-directory /etc/telegraf/telegraf.d
+    network_mode: "{{ telegraf_agent_docker_network_mode }}"
+    volumes:
+      - /etc/telegraf:/etc/telegraf:ro
+      - /:/hostfs:ro
+      - /etc:/hostfs/etc:ro
+      - /proc:/hostfs/proc:ro
+      - /sys:/hostfs/sys:ro
+      - /var/run:/var/run:ro
+    env:
+      HOST_MOUNT_PREFIX: /hostfs
+      HOST_ETC: /hostfs/etc
+      HOST_PROC: /hostfs/proc
+      HOST_SYS: /hostfs/sys

tasks/main.yml

@@ -4,21 +4,24 @@
 - name: "Install on RedHat"
   include_tasks: "RedHat.yml"
   when:
-    - ansible_os_family == "RedHat"
+    - ansible_os_family == "RedHat" and not telegraf_agent_docker
 
 - name: "Install on Debian"
   include_tasks: "Debian.yml"
   when:
-    - ansible_os_family == "Debian"
+    - ansible_os_family == "Debian" and not telegraf_agent_docker
   tags:
     - telegraf
     - packages
 
 - name: "Install on Suse"
   include_tasks: "Suse.yml"
-  when: ansible_os_family == "Suse"
+  when: ansible_os_family == "Suse" and not telegraf_agent_docker
 
-- name: "Configure telegraf"
+- include_tasks: "docker.yml"
+  when: telegraf_agent_docker
+
+- name: "Configure Telegraf"
   include_tasks: "configure_linux.yml"
   when:
     - ansible_os_family != "Windows"
@@ -26,4 +29,4 @@
 - name: "Install / Configure telegraf on Windows"
   include_tasks: "configure_windows.yml"
   when:
-    - ansible_os_family == "Windows"
+    - ansible_os_family == "Windows" and not telegraf_agent_docker