Install Grafana Agent on a Linux host using Ansible

This guide shows how to install Grafana Agent on a Linux host using Ansible and to use it to push logs to Grafana Cloud.

Before you begin

Before you begin, you should have the following available:

A Grafana Cloud account.
A Linux machine
Command line (terminal) access to that Linux machine with unzip binary installed
Account permissions sufficient to install and use Grafana Agent on the Linux machine
Ansible installed on the Linux machine

Choose your Grafana Agent installation method

This guide covers two methods for installing and configuring Grafana Agent using Ansible:

Installing Grafana Agent in Flow mode
Installing Grafana Agent in static mode

Depending on your specific needs and the configuration of your environment, you may choose one method over the other for better compatibility or ease of setup.

Install Grafana Agent in flow mode using Ansible

This Ansible playbook installs Grafana Agent in Flow mode and also creates a systemd service to manage it.

It creates a user named grafana-agent on the Linux machine for running Grafana Agent.

Create a file named grafana-agent.yml and add the following:

- name: Install Grafana Agent Flow
  hosts: all
  become: true
  tasks:
    - name: Install Grafana Agent Flow
      ansible.builtin.include_role:
        name: grafana.grafana.grafana_agent
      vars:
        grafana_agent_mode: flow
        # Change config file on the host to .river
        grafana_agent_config_filename: config.river
        # Change config file to be copied
        grafana_agent_provisioned_config_file: '<path-to-config-file>'
        # Remove default flags
        grafana_agent_flags_extra:
          server.http.listen-addr: '0.0.0.0:12345'

Replace the following field values:
- <path-to-config-file-on-localhost> with the path to river configuration file on the Ansible Controller (Localhost).

Install Grafana Agent in static mode using Ansible

This Ansible playbook installs Grafana Agent in static mode and also creates a systemd service to manage it. It creates a user named grafana-agent on the Linux machine for running Grafana Agent.

Create a file named grafana-agent.yml and add the following:

- name: Install Grafana Agent in static mode
  hosts: all
  become: true

  vars:
    grafana_cloud_api_key: <Your Cloud Access Policy token> # Example - glc_eyJrIjoiYjI3NjI5MGQxZTcyOTIxYTc0MDgzMGVhNDhlODNhYzA5OTk2Y2U5YiIsIm4iOiJhbnNpYmxldGVzdCIsImlkIjo2NTI5
    logs_username: <loki-username> # Example - 411478
    loki_url: <loki-push-url> # Example - https://logs-prod-017.grafana.net/loki/api/v1/push
  tasks:
    - name: Install Grafana Agent in static mode
      ansible.builtin.include_role:
        name: grafana_agent
      vars:
        grafana_agent_logs_config:
          configs:
            - clients:
                - basic_auth:
                    password: '{{ grafana_cloud_api_key }}'
                    username: '{{ logs_username }}'
                  url: '{{ loki_url }}'
              name: default
              positions:
                filename: /tmp/positions.yaml
              scrape_configs:
                - job_name: integrations/node_exporter_direct_scrape
                  static_configs:
                    - targets:
                        - localhost
                      labels:
                        instance: hostname
                        __path__: /var/log/*.log
                        job: integrations/node_exporter
              target_config:
                sync_period: 10s

Replace the following field values:
- <Your Cloud Access Policy token> with a token from the Cloud Access Policy you created in the Grafana Cloud portal.
- <loki-username> with the Loki Username
- <loki-push-url> with the push endpoint URL of Loki Instance

Run the Ansible playbook on the Linux machine

In the Linux machine’s terminal, run the following command from the directory where the Ansible playbook is located.

ansible-playbook grafana-agent.yml

Validate

Grafana Agent service on the Linux machine should be active and running. You should see a similar output:

$ sudo systemctl status grafana-agent.service
  grafana-agent.service - Grafana Agent
    Loaded: loaded (/etc/systemd/system/grafana-agent.service; enabled; vendor preset: enabled)
    Active: active (running) since Wed 2022-07-20 09:56:15 UTC; 36s ago
  Main PID: 3176 (agent-linux-amd)
    Tasks: 8 (limit: 515)
    Memory: 92.5M
      CPU: 380ms
    CGroup: /system.slice/grafana-agent.service
      └─3176 /usr/local/bin/agent-linux-amd64 --config.file=/etc/grafana-cloud/agent-config.yaml

In a Grafana Cloud stack, click Explore in the left-side menu.
At the top of the page, use the dropdown menu to select your Loki logs data source. In the Log Browser, run the query {job="integrations/node_exporter"}