Chef recipe to automatically restart docker containers or generic services affected by an update of dynatrace agent

dynatrace-soft-restart.rb

ruby_block "check-restart-dynatrace" do
  block do
    headers = {:Authorization => "Api-Token #{provider['api_key']}"}
    client = Chef::HTTP.new(provider['url'])
    processes = JSON.parse(client.get('/processes?includeDetails=true', headers))
    hosts = JSON.parse(client.get('/hosts?includeDetails=true', headers))
    host_found = hosts.select { |host| host['discoveredName'] == node['hostname'] }.first
    if host_found
      host_id = host_found['entityId']
      processes.select { |process| process['fromRelationships']['isProcessOf'].include?(host_id) }
          .select { |process| process['monitoringState']['restartRequired'] }.each do |p|
        if p['metadata']['dockerContainerNames']
          container_name = p['metadata']['dockerContainerNames'].first
          Chef::Log.info("#{container_name} needs restart")
          resources(:docker_container => container_name).run_action(:restart)
        else
          begin
            service_name = p['discoveredName']
            resources(:service => service_name).run_action(:restart)
          rescue Chef::Exceptions::ResourceNotFound
            Chef::Log.info("#{service_name}  not found")
          end
        end
      end
    end
  end
end