true Scout, Eric Lindvall

http, url monitoring

require 'benchmark'
require 'net/http'
require 'net/https'
require 'uri'

class UrlMonitor < Scout::Plugin
  include Net
  
  TEST_USAGE = "#{File.basename($0)} url URL last_run LAST_RUN"
  TIMEOUT_LENGTH = 50 # seconds
  
  def build_report
    url = option("url").to_s.strip
    if url.empty?
      return error("A url wasn't provided.")
    end
    
    unless url =~ %r{\Ahttps?://}
      url = "http://#{url}"
    end
    
    response = nil
    response_time = Benchmark.realtime do
      response = http_response(url)
    end

    report(:status => response.class.to_s[/^Net::HTTP(.*)$/, 1],
           :response_time => response_time)
    
    is_up = valid_http_response?(response) ? 1 : 0
    report(:up => is_up)
    
    if is_up != memory(:was_up)
      if is_up == 0
        alert("The URL [#{url}] is not responding", unindent(<<-EOF))
            URL: #{url}

            Code: #{response.code}
            Status: #{response.class.to_s[/^Net::HTTP(.*)$/, 1]}
            Message: #{response.message}
          EOF
        remember(:down_at => Time.now)
      else
        if memory(:was_up) && memory(:down_at)
          alert( "The URL [#{url}] is responding again",
                 "URL: #{url}\n\nStatus: #{response.class.to_s[/^Net::HTTP(.*)$/, 1]}. " +
                 "Was unresponsive for #{(Time.now - memory(:down_at)).to_i} seconds")
        else
          alert( "The URL [#{url}] is responding",
                 "URL: #{url}\n\nStatus: #{response.class.to_s[/^Net::HTTP(.*)$/, 1]}. ")
        end
        memory.delete(:down_at)
      end
    end
    
    remember(:was_up => is_up)
  rescue Exception => e
    error( "Error monitoring url [#{url}]",
           "#{e.message}<br><br>#{e.backtrace.join('<br>')}" )
  end
  
  def valid_http_response?(result)
    [HTTPOK,HTTPFound].include?(result.class) 
  end
  
  # returns the http response (string) from a url
  def http_response(url)
    uri = URI.parse(url)

    response = nil
    retry_url_trailing_slash = true
    retry_url_execution_expired = true
    begin
      http = Net::HTTP.new(uri.host,uri.port)
      http.use_ssl = url =~ %r{\Ahttps://}
      http.start(){|http|
            http.open_timeout = TIMEOUT_LENGTH
            req = Net::HTTP::Get.new((uri.path != '' ? uri.path : '/' ) + (uri.query ? ('?' + uri.query) : ''))
            if uri.user && uri.password
              req.basic_auth uri.user, uri.password
            end
            response = http.request(req)
      }
    rescue Exception => e
      # forgot the trailing slash...add and retry
      if e.message == "HTTP request path is empty" and retry_url_trailing_slash
        url += '/'
        uri = URI.parse(url)
        h = Net::HTTP.new(uri.host)
        retry_url_trailing_slash = false
        retry
      elsif e.message =~ /execution expired/ and retry_url_execution_expired
        retry_url_execution_expired = false
        retry
      else
        response = e.to_s
      end
    end
        
    return response
  end

  def unindent(string)
    indentation = string[/\A\s*/]
    string.strip.gsub(/^#{indentation}/, "")
  end
end

2007-12-12T15:50:57-08:00

Monitors the availability of a URL, sending an alert if the URL is not reachable. <br/> An alert is generated every time the URL is unreachable. <br/> Accepts a single option - the url to monitor. false 2 --- | options: url: name: Url notes: The full URL (including http://) of the URL to monitor. You can provide basic authentication options as well (http://user:pass@domain.com) default: "http://www.scoutapp.com/" metadata: response_time: label: Response Time units: secs precision: 2 larger_is_better: false up: label: Url Reachable precision: 0 larger_is_better: true URL Monitoring

242

3.0

URL Monitoring Plugin ===================== Created by [Highgroove Studios LLC](http://www.highgroove.com) Compatibility ------------- Works fully on Linux and OSX.

Monitors the availability of a URL, sending an alert if the URL is not reachable. The following data is reported: * Url Reachable (1 if reachable, 0 if not) * Response Time (secs)

linux macosx

2010-01-21T15:08:55-08:00

http://github.com/highgroove/scout-plugins/raw/master/url_monitor/url_monitor.rb