dns_query_time plugin: added

diff --git a/python.d/dns_query_time.chart.py b/python.d/dns_query_time.chart.py
new file mode 100644 (file)
index 0000000..f391175
--- /dev/null
+++ b/python.d/dns_query_time.chart.py
@@ -0,0 +1,129 @@
+try:
+    from time import monotonic as time
+except ImportError:
+    from time import time
+try:
+    import dns.message, dns.query, dns.name
+    DNS_PYTHON = True
+except ImportError:
+    DNS_PYTHON = False
+try:
+    from queue import Queue
+except ImportError:
+    from Queue import Queue
+from random import choice
+from threading import Thread
+from socket import gethostbyname, gaierror
+from base import SimpleService
+
+
+# default module values (can be overridden per job in `config`)
+update_every = 5
+priority = 60000
+retries = 60
+
+
+class Service(SimpleService):
+    def __init__(self, configuration=None, name=None):
+        SimpleService.__init__(self, configuration=configuration, name=name)
+        self.order = list()
+        self.definitions = dict()
+        self.timeout = self.configuration.get('response_timeout', 4)
+        self.aggregate = self.configuration.get('aggregate', True)
+        self.domains = self.configuration.get('domains')
+        self.server_list = self.configuration.get('dns_servers')
+
+    def check(self):
+        if not DNS_PYTHON:
+            self.error('\'python-dnspython\' package is needed to use dns_query_time.chart.py')
+            return False
+
+        self.timeout = self.timeout if isinstance(self.timeout, int) else 4
+        self.update_every = self.timeout + 1 if self.update_every <= self.timeout else self.update_every
+ 
+        if not all([self.domains, self.server_list,
+                    isinstance(self.server_list, str), isinstance(self.domains, str)]):
+            self.error('server_list and domain_list can\'t be empty')
+            return False
+        else:
+            self.domains, self.server_list = self.domains.split(), self.server_list.split()
+
+        for ns in self.server_list:
+            if not check_ns(ns):
+                self.info('Bad NS: %s' % ns)
+                self.server_list.remove(ns)
+                if not self.server_list:
+                    return False
+
+        data = self._get_data(timeout=1)
+
+        down_servers = [s[2:] for s in data if data[s] == -100]
+        if down_servers:
+            self.info('Removed due to non response %s' % down_servers)
+            self.server_list = [s for s in self.server_list if s not in down_servers]
+        if self.server_list:
+            self._data_from_check = data
+            self.order, self.definitions = create_charts(aggregate=self.aggregate, server_list=self.server_list)
+            self.info(str({'domains': len(self.domains), 'servers': self.server_list}))
+            return True
+        else:
+            return False
+
+    def _get_data(self, timeout=None):
+        return dns_request(self.server_list, timeout or self.timeout, self.domains)
+
+
+def dns_request(server_list, timeout, domains):
+    threads = list()
+    que = Queue()
+    result = dict()
+
+    def dns_req(ns, t, q):
+        domain = dns.name.from_text(choice(domains))
+        request = dns.message.make_query(domain, dns.rdatatype.A)
+
+        try:
+            dns_start = time()
+            dns.query.udp(request, ns, timeout=t)
+            dns_end = time()
+            query_time = round((dns_end - dns_start) * 1000)
+            q.put({''.join(['ns', ns]): query_time})
+        except dns.exception.Timeout:
+            q.put({''.join(['ns', ns]): -100})
+
+    for server in server_list:
+        th = Thread(target=dns_req, args=(server, timeout, que))
+        th.start()
+        threads.append(th)
+
+    for th in threads:
+        th.join()
+        result.update(que.get())
+
+    return result
+
+
+def check_ns(ns):
+    try:
+        return gethostbyname(ns)
+    except gaierror:
+        return False
+
+
+def create_charts(aggregate, server_list):
+    if aggregate:
+        order = ['dns_group']
+        definitions = {'dns_group': {'options': [None, "DNS Response Time", "ms", 'name servers',
+                                                 'resp.time', 'line'], 'lines': []}}
+        for ns in server_list:
+            definitions['dns_group']['lines'].append([''.join(['ns', ns]), ns, 'absolute'])
+
+        return order, definitions
+    else:
+        order = [''.join(['dns_', ns]) for ns in server_list]
+        definitions = dict()
+        for ns in server_list:
+            definitions[''.join(['dns_', ns])] = {'options': [None, "DNS Response Time", "ms", ns,
+                                                              'resp.time', 'area'],
+                                                  'lines': [[''.join(['ns', ns]), ns, 'absolute']]}
+        return order, definitions