check-marathon-task.rb in sensu-plugins-mesos-1.0.0

- old
+ new
@@ -31,50 +31,146 @@
 
 require 'sensu-plugin/check/cli'
 require 'net/http'
 require 'json'
 
+# This plugin checks that the given Mesos/Marathon task is running properly.
+#
+# This means that all of the following is true:
+# 1. There are N tasks for the app, as defined by the --instances parameter
+# 2. Each task's state is running
+# 3. No task is unhealthy, as defined in Marathon
+#
+# A task is seen as **unhealthy** by Marathon if any of the health checks for
+# the task is not **alive**.  Alive means that a check has a last success that
+# is more recent than last failure. It's not alive if the last failure is more
+# recent than the last success, or if the last success doesn't exist at all.
 class MarathonTaskCheck < Sensu::Plugin::Check::CLI
   check_name 'CheckMarathonTask'
 
-  option :server, short: '-s SERVER', long: '--server SERVER', required: true
-  option :port, short: '-p PORT', long: '--port PORT', default: 8080
-  option :task, short: '-t TASK', long: '--task TASK', required: true
-  option :instances, short: '-i INSTANCES', long: '--instances INSTANCES', required: true, proc: proc(&:to_i)
+  option :server,
+         short: '-s SERVER',
+         long: '--server SERVER',
+         required: true
 
+  option :port,
+         short: '-p PORT',
+         long: '--port PORT',
+         default: 8080
+
+  option :uri,
+         description: 'Endpoint URI',
+         short: '-u URI',
+         long: '--uri URI',
+         default: '/v2/tasks?status=running'
+
+  option :task,
+         short: '-t TASK',
+         long: '--task TASK',
+         required: true
+
+  option :instances,
+         short: '-i INSTANCES',
+         long: '--instances INSTANCES',
+         required: true,
+         proc: proc(&:to_i)
+
+  option :protocol,
+         short: '-P PROTOCOL',
+         long: '--protocol PROTOCOL',
+         required: false,
+         default: 'http'
+
+  option :username,
+         short: '-u USERNAME',
+         long: '--username USERNAME',
+         required: false
+
+  option :password,
+         long: '--password PASSWORD',
+         required: false
+
   def run
-    if config[:instances] == 0
+    if config[:instances].zero?
       unknown 'number of instances should be an integer'
     end
 
+    if !config[:username].nil? && config[:password].nil? ||
+       config[:username].nil? && !config[:password].nil?
+      unknown 'You must provide both username and password'
+    end
+
     failures = []
+    uri = config[:uri]
     config[:server].split(',').each do |s|
       begin
-        url = URI.parse("http://#{s}:#{config[:port]}/v2/tasks?state=running")
+        url = URI.parse("#{config[:protocol]}://#{s}:#{config[:port]}#{uri}")
         req = Net::HTTP::Get.new(url)
         req.add_field('Accept', 'application/json')
-        r = Net::HTTP.new(url.host, url.port).start do |h|
+        if !config[:username].nil? && !config[:password].nil?
+          req.basic_auth(config[:username], config[:password])
+        end
+        r = Net::HTTP.start(url.host, url.port,
+                            use_ssl: config[:protocol] == 'https') do |h|
           h.request(req)
         end
 
-        tasks = JSON.parse(r.body)['tasks']
-        tasks.select! do |t|
-          t['appId'] == "/#{config[:task]}"
-        end
+        ok_count, unhealthy = check_tasks r.body
 
-        message = "#{tasks.length}/#{config[:instances]} #{config[:task]} tasks running"
+        message = "#{ok_count}/#{config[:instances]} #{config[:task]} tasks running"
 
-        if tasks.length < config[:instances]
+        if unhealthy.any?
+          message << ":\n" << unhealthy.join("\n")
+        end
+
+        if unhealthy.any? || ok_count < config[:instances]
           critical message
         end
 
         ok message
       rescue Errno::ECONNREFUSED, SocketError
         failures << "Marathon on #{s} could not be reached"
-      rescue
-        failures << "error caught trying to reach Marathon on #{s}"
+      rescue => err
+        failures << "error caught trying to reach Marathon on #{s}: #{err}"
       end
     end
 
     unknown "marathon task state could not be retrieved:\n" << failures.join("\n")
+  end
+
+  # Parses JSON data as returned from Marathon's tasks API
+  # @param data [String] Server response
+  # @return [Numeric, [String]] Number of running tasks and a list of error
+  #                             messages from unhealthy tasks
+  def check_tasks(data)
+    begin
+      tasks = JSON.parse(data)['tasks']
+    rescue JSON::ParserError
+      raise "Could not parse JSON response: #{data}"
+    end
+
+    if tasks.nil?
+      raise "No tasks in server response: #{data}"
+    end
+
+    tasks.select! do |t|
+      t['appId'] == "/#{config[:task]}"
+    end
+
+    unhealthy = []
+
+    # Collect last error message for all health checks that are not alive
+    tasks.each do |task|
+      checks = task['healthCheckResults'] || []
+      checks.each do |check|
+        if check['alive']
+          next
+        end
+        message = check['lastFailureCause'] ||
+                  'Health check not alive'
+        unhealthy << message
+      end
+    end
+
+    [tasks.length, unhealthy]
   end
 end