Merge pull request #3069 from DataDog/oceane/http_check_reverse_conte…

…nt_match

[HTTP CHECK] Add an Option to mark check as DOWN if a content is found

checks.d/http_check.py

@@ -173,6 +173,7 @@ def _load_conf(self, instance):
         headers.update(config_headers)
         url = instance.get('url')
         content_match = instance.get('content_match')
+        reverse_content_match = _is_affirmative(instance.get('reverse_content_match', False))
         response_time = _is_affirmative(instance.get('collect_response_time', True))
         if not url:
             raise Exception("Bad configuration. You must specify a url")
@@ -186,15 +187,32 @@ def _load_conf(self, instance):
         allow_redirects = _is_affirmative(instance.get('allow_redirects', True))
 
         return url, username, password, method, data, http_response_status_code, timeout, include_content,\
-            headers, response_time, content_match, tags, ssl, ssl_expire, instance_ca_certs,\
+            headers, response_time, content_match, reverse_content_match, tags, ssl, ssl_expire, instance_ca_certs,\
             weakcipher, ignore_ssl_warning, skip_proxy, allow_redirects
 
     def _check(self, instance):
         addr, username, password, method, data, http_response_status_code, timeout, include_content, headers,\
-            response_time, content_match, tags, disable_ssl_validation,\
+            response_time, content_match, reverse_content_match, tags, disable_ssl_validation,\
             ssl_expire, instance_ca_certs, weakcipher, ignore_ssl_warning, skip_proxy, allow_redirects = self._load_conf(instance)
         start = time.time()
 
+        def send_status_up(logMsg):
+            self.log.debug(logMsg)
+            service_checks.append((
+                self.SC_STATUS, Status.UP, "UP"
+            ))
+
+        def send_status_down(loginfo, message):
+            self.log.info(loginfo)
+            self.log.debug("Content returned:\n%s" % content)
+            if include_content:
+                message += '\nContent: {}'.format(content[:CONTENT_LENGTH])
+            service_checks.append((
+                self.SC_STATUS,
+                Status.DOWN,
+                message
+            ))
+
         service_checks = []
         try:
             parsed_uri = urlparse(addr)
@@ -296,26 +314,21 @@ def _check(self, instance):
                 # r.text is the response content decoded by `requests`, of type `unicode`
                 content = r.text if type(content_match) is unicode else r.content
                 if re.search(content_match, content, re.UNICODE):
-                    self.log.debug("%s is found in return content" % content_match)
-                    service_checks.append((
-                        self.SC_STATUS, Status.UP, "UP"
-                    ))
+                    if reverse_content_match:
+                        send_status_down("%s is found in return content with the reverse_content_match option" % content_match,
+                            'Content "%s" found in response with the reverse_content_match' % content_match)
+                    else:
+                        send_status_up("%s is found in return content" % content_match)
+
                 else:
-                    self.log.info("%s not found in content" % content_match)
-                    self.log.debug("Content returned:\n%s" % content)
-                    message = 'Content "%s" not found in response.' % content_match
-                    if include_content:
-                        message += '\nContent: {}'.format(content[:CONTENT_LENGTH])
-                    service_checks.append((
-                        self.SC_STATUS,
-                        Status.DOWN,
-                        message
-                    ))
+                    if reverse_content_match:
+                        send_status_up("%s is not found in return content with the reverse_content_match option" % content_match)
+                    else:
+                        send_status_down("%s is not found in return content" % content_match,
+                            'Content "%s" not found in response.' % content_match)
+
             else:
-                self.log.debug("%s is UP" % addr)
-                service_checks.append((
-                    self.SC_STATUS, Status.UP, "UP"
-                ))
+                send_status_up("%s is UP" % addr)
 
         if ssl_expire and parsed_uri.scheme == "https":
             status, msg = self.check_cert_expiration(instance, timeout, instance_ca_certs)

conf.d/http_check.yaml.example

@@ -29,6 +29,11 @@ instances:
     # content_match: 'In Stock'
     # content_match: '^(Bread|Apples|Very small rocks|Cider|Gravy|Cherries|Mud|Churches|Lead) float(s)? in water'
 
+    # The (optional) reverse_content_match parameter will allow the content_match
+    # to work the other way around. That means that the check will report
+    # as DOWN if the string is found.
+    # reverse_content_match: false
+
     # If your service uses basic authentication, you can optionally
     # specify a username and password that will be used in the check.
     #

tests/checks/integration/test_http_check.py

@@ -55,6 +55,40 @@
         'timeout': 1,
         'check_certificate_expiration': False,
         'content_match': u'メインページ'
+    }, {
+        'name': 'cnt_mismatch_unicode',
+        'url': 'https://ja.wikipedia.org/',
+        'timeout': 1,
+        'check_certificate_expiration': False,
+        'content_match': u'メインペーー'
+    }, {
+        'name': 'cnt_mismatch_reverse',
+        'url': 'https://github.com',
+        'timeout': 1,
+        'reverse_content_match': True,
+        'check_certificate_expiration': False,
+        'content_match': 'thereisnosuchword'
+    }, {
+        'name': 'cnt_match_reverse',
+        'url': 'https://github.com',
+        'timeout': 1,
+        'reverse_content_match': True,
+        'check_certificate_expiration': False,
+        'content_match': '(thereisnosuchword|github)'
+    }, {
+        'name': 'cnt_mismatch_unicode_reverse',
+        'url': 'https://ja.wikipedia.org/',
+        'timeout': 1,
+        'reverse_content_match': True,
+        'check_certificate_expiration': False,
+        'content_match': u'メインペーー'
+    }, {
+        'name': 'cnt_match_unicode_reverse',
+        'url': 'https://ja.wikipedia.org/',
+        'timeout': 1,
+        'reverse_content_match': True,
+        'check_certificate_expiration': False,
+        'content_match': u'メインページ'
     }
     ]
 }
@@ -227,6 +261,19 @@ def test_check(self):
         self.assertServiceCheckOK("http.can_connect", tags=tags)
         tags = ['url:https://ja.wikipedia.org/', 'instance:cnt_match_unicode']
         self.assertServiceCheckOK("http.can_connect", tags=tags)
+        tags = ['url:https://ja.wikipedia.org/', 'instance:cnt_mismatch_unicode']
+        self.assertServiceCheckCritical("http.can_connect", tags=tags)
+        self.assertServiceCheckOK("http.can_connect", tags=tags, count=0)
+        tags = ['url:https://github.com', 'instance:cnt_mismatch_reverse']
+        self.assertServiceCheckOK("http.can_connect", tags=tags)
+        self.assertServiceCheckCritical("http.can_connect", tags=tags, count=0)
+        tags = ['url:https://github.com', 'instance:cnt_match_reverse']
+        self.assertServiceCheckCritical("http.can_connect", tags=tags)
+        tags = ['url:https://ja.wikipedia.org/', 'instance:cnt_mismatch_unicode_reverse']
+        self.assertServiceCheckOK("http.can_connect", tags=tags)
+        tags = ['url:https://ja.wikipedia.org/', 'instance:cnt_match_unicode_reverse']
+        self.assertServiceCheckCritical("http.can_connect", tags=tags)
+        self.assertServiceCheckOK("http.can_connect", tags=tags, count=0)
 
         self.coverage_report()