From bae30da9659c0e4b70b8fb4ee999f37126c811c4 Mon Sep 17 00:00:00 2001
From: Hippolyte HENRY <zippolyte@users.noreply.github.com>
Date: Tue, 13 Jun 2017 13:46:00 -0400
Subject: [PATCH] [go_expvar] Fix path tag appended to all metrics matching
 path regex (#472)

---
 go_expvar/CHANGELOG.md              |  5 +++++
 go_expvar/check.py                  |  5 ++---
 go_expvar/ci/fixtures/expvar_output |  3 ++-
 go_expvar/manifest.json             |  2 +-
 go_expvar/test_go_expvar.py         | 20 ++++++++++++++++++++
 5 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/go_expvar/CHANGELOG.md b/go_expvar/CHANGELOG.md
index b0542567be93d..6ceb84969648f 100644
--- a/go_expvar/CHANGELOG.md
+++ b/go_expvar/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG - go_expvar
 
+1.0.3 / Unreleased
+==================
+
+* [BUGFIX] Fix path tag appended to all metrics matching path regex
+
 1.0.2 / Unreleased
 ==================
 
diff --git a/go_expvar/check.py b/go_expvar/check.py
index 9818fe5dd6232..6d6cce7259296 100644
--- a/go_expvar/check.py
+++ b/go_expvar/check.py
@@ -175,8 +175,7 @@ def parse_expvar_data(self, data, tags, metrics, max_metrics, namespace):
 
             for traversed_path, value in values:
                 actual_path = ".".join(traversed_path)
-                if tag_by_path:
-                    metric_tags.append("path:%s" % actual_path)
+                path_tag = ["path:%s" % actual_path] if tag_by_path else []
 
                 metric_name = alias or self.normalize(actual_path, namespace, fix_case=True)
 
@@ -191,7 +190,7 @@ def parse_expvar_data(self, data, tags, metrics, max_metrics, namespace):
                                  "Please contact support@datadoghq.com for more information.")
                     return
 
-                SUPPORTED_TYPES[metric_type](self, metric_name, value, metric_tags)
+                SUPPORTED_TYPES[metric_type](self, metric_name, value, metric_tags + path_tag)
                 count += 1
 
     def deep_get(self, content, keys, traversed_path=None):
diff --git a/go_expvar/ci/fixtures/expvar_output b/go_expvar/ci/fixtures/expvar_output
index e60a32a77599f..94bc8d4cbe7ba 100644
--- a/go_expvar/ci/fixtures/expvar_output
+++ b/go_expvar/ci/fixtures/expvar_output
@@ -4,5 +4,6 @@
 "random_walk": 0.2813217443279966,
 "steps": 5,
 "public": {"bla": 1},
-"random_value": 0.6868230728671094
+"random_value": 0.6868230728671094,
+"array": [{"key":10},{"key":15}]
 }
\ No newline at end of file
diff --git a/go_expvar/manifest.json b/go_expvar/manifest.json
index 0a3c66f68eb62..590db4f918100 100644
--- a/go_expvar/manifest.json
+++ b/go_expvar/manifest.json
@@ -11,6 +11,6 @@
     "mac_os",
     "windows"
   ],
-  "version": "1.0.2",
+  "version": "1.0.3",
   "guid": "33557f7a-5f24-43f3-9551-78432894e539"
 }
diff --git a/go_expvar/test_go_expvar.py b/go_expvar/test_go_expvar.py
index e3286ab16d5dc..1ea9018d80c9d 100644
--- a/go_expvar/test_go_expvar.py
+++ b/go_expvar/test_go_expvar.py
@@ -249,6 +249,26 @@ def test_deep_get(self):
         results = self.check.deep_get(content, ['list', '.*', 'value'], [])
         self.assertEqual(sorted(results), sorted(expected))
 
+    # Test that the path tags get correctly added when metric has alias
+    def test_alias_tag_path(self):
+        mock_config = {
+            "instances": [{
+                "expvar_url": self._expvar_url,
+                "metrics": [
+                    {
+                        "path": "array/\d+/key",
+                        "alias": "array.dict.key",
+                        "type": "gauge",
+                    }
+                ]
+            }]
+        }
+        self.run_check(mock_config, mocks=self.mocks)
+
+        shared_tags = ['expvar_url:{0}'.format(self._expvar_url)]
+        self.assertMetric("array.dict.key", count=1, tags=shared_tags + ["path:array.0.key"])
+        self.assertMetric("array.dict.key", count=1, tags=shared_tags + ["path:array.1.key"])
+
 @attr(requires='go_expvar')
 class TestGoExpVar(AgentCheckTest):