# cookbooks/monitoring/default.rb

mon = node['monitoring']
version = mon['node_exporter_version']

group mon['node_exporter_user'] do
  gid mon['node_exporter_uid']
end

user mon['node_exporter_user'] do
  uid mon['node_exporter_uid']
  gid mon['node_exporter_uid']
  home '/var/lib/node_exporter'
  shell '/usr/sbin/nologin'
  system_user true
end

directory '/var/lib/node_exporter' do
  owner mon['node_exporter_user']
  group mon['node_exporter_user']
  mode '0755'
end

directory mon['textfile_dir'] do
  owner mon['node_exporter_user']
  group mon['node_exporter_user']
  mode '0755'
end

execute 'download-node-exporter' do
  command "curl -fsSL https://github.com/prometheus/node_exporter/releases/download/v#{version}/node_exporter-#{version}.linux-amd64.tar.gz | tar -xz -C /usr/local/bin --strip-components=1 node_exporter-#{version}.linux-amd64/node_exporter"
  not_if "test -f /usr/local/bin/node_exporter && /usr/local/bin/node_exporter --version 2>&1 | grep -q #{version}"
end

file '/usr/local/bin/node_exporter' do
  owner 'root'
  group 'root'
  mode '0755'
end

template '/etc/systemd/system/node_exporter.service' do
  source 'templates/node_exporter.service.erb'
  owner 'root'
  group 'root'
  mode '0644'
  variables(
    user: mon['node_exporter_user'],
    port: mon['node_exporter_port'],
    textfile_dir: mon['textfile_dir']
  )
  notifies :restart, 'service[node_exporter]'
end

http_request '/tmp/health_check' do
  url mon['health_check_url']
end

template '/etc/alerting.yml' do
  source 'templates/alerting.yml.erb'
  owner 'root'
  group 'root'
  mode '0644'
  variables(
    alert_email: mon['alert_email'],
    port: mon['node_exporter_port']
  )
end

execute 'systemctl daemon-reload' do
  command 'systemctl daemon-reload'
end

service 'node_exporter' do
  action [:enable, :start]
end