Ansible Role: node exporter

Description

Deploy prometheus node exporter using ansible.

Requirements

• Ansible >= 2.7 (It might work on previous versions, but we cannot guarantee it)
• gnu-tar on Mac deployer host (brew install gnu-tar)

Role Variables

All variables which can be overridden are stored in defaults/main.yml file as well as in table below.

Name	Default Value	Description
node_exporter_version	1.0.0	Node exporter package version. Also accepts latest as parameter.
node_exporter_binary_local_dir	""	Allows to use local packages instead of ones distributed on github. As parameter it takes a directory where node_exporter binary is stored on host on which ansible is ran. This overrides node_exporter_version parameter
node_exporter_web_listen_address	"0.0.0.0:9100"	Address on which node exporter will listen
node_exporter_enabled_collectors	[ systemd, textfile ]	List of additionally enabled collectors. It adds collectors to those enabled by default
node_exporter_disabled_collectors	[]	List of disabled collectors. By default node_exporter disables collectors listed here.
node_exporter_textfile_dir	"/var/lib/node_exporter"	Directory used by the Textfile Collector. To get permissions to write metrics in this directory, users must be in node-exp system group.
node_exporter_tls_server_config	{}	Configuration for TLS authentication. Keys and values are the same as in node_exporter docs.
node_exporter_http_server_config	{}	Config for HTTP/2 support. Keys and values are the same as in node_exporter docs.
node_exporter_basic_auth_users	{}	Dictionary of users and password for basic authentication. Passwords are automatically hashed with bcrypt.

Example

Playbook

Use it in a playbook as follows:

- hosts: all
  roles:
    - cloudalchemy.node-exporter

TLS config

Before running node_exporter role, user needs to provision their own certificate and key.

- hosts: all
  pre_tasks:
    - name: Create node_exporter cert dir
      file:
        path: "/etc/node_exporter"
        state: directory
        owner: root
        group: root

    - name: Create cert and key
      openssl_certificate:
        path: /etc/node_exporter/tls.cert
        csr_path: /etc/node_exporter/tls.csr
        privatekey_path: /etc/node_exporter/tls.key
        provider: selfsigned
  roles:
    - cloudalchemy.node-exporter
  vars:
    node_exporter_tls_server_config:
      cert_file: /etc/node_exporter/tls.cert
      key_file: /etc/node_exporter/tls.key
    node_exporter_basic_auth_users:
      randomuser: examplepassword 

Demo site

We provide demo site for full monitoring solution based on prometheus and grafana. Repository with code and links to running instances is available on github and site is hosted on DigitalOcean.

Local Testing

The preferred way of locally testing the role is to use Docker and molecule (v2.x). You will have to install Docker on your system. See "Get started" for a Docker package suitable to for your system. We are using tox to simplify process of testing on multiple ansible versions. To install tox execute:

pip3 install tox

To run tests on all ansible versions (WARNING: this can take some time)

tox

To run a custom molecule command on custom environment with only default test scenario:

tox -e py35-ansible28 -- molecule test -s default

For more information about molecule go to their docs.

If you would like to run tests on remote docker host just specify DOCKER_HOST variable before running tox tests.

Travis CI

Combining molecule and travis CI allows us to test how new PRs will behave when used with multiple ansible versions and multiple operating systems. This also allows use to create test scenarios for different role configurations. As a result we have a quite large test matrix which will take more time than local testing, so please be patient.

Contributing

See contributor guideline.

License

This project is licensed under MIT License. See LICENSE for more details.