feat: monitoring stack

[leopaul36]

Linked issues

• Fix Add a monitoring stack playbook #51

Changes

• Added the ash.avalanche.install_monitoring_stack playbook to install Prometheus, Prometheus Node Exporter and Grafana
• Added the Prometheus collection and Grafana role in requirements.txt

Additional comments

Dashboards

Dashboards come from https://github.com/ava-labs/avalanche-monitoring, I opened ava-labs/avalanche-monitoring#8 to fix some light issues.

The Subnets dashboard will require templating so I saved it for later.

Warnings

When running the ash.avalanche.install_monitoring_stack playbook from the ansible-avalanche-getting-started env, the following warnings can be seen:

[WARNING]: Collection prometheus.prometheus does not support Ansible version 2.14.3

• docs state ~= 2.14.0 so we should be good.

[DEPRECATION WARNING]: "include" is deprecated, use include_tasks/import_tasks instead. See https://docs.ansible.com/ansible-
core/2.14/user_guide/playbooks_reuse_includes.html for details. This feature will be removed in version 2.16. Deprecation warnings can be
disabled by setting deprecation_warnings=False in ansible.cfg.

• Comes from the include statements in tasks/main.yml, the role is quite old but still does the job.