Rewrite label names to be Prometheus compliant

I am running into issues where my OpenTSDB tags with periods in their names are failing to be scraped by Prometheus. It seems like the most logical place to fix that is in this exporter. This approach takes any tag name that would fail validation in Prometheus and rewrites it to pass.
adobe-research · Oct 5, 2020 · dde951f · dde951f
1 parent 021b8da
commit dde951f
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Showing 6 changed files with 35 additions and 13 deletions.
diff --git a/VERSION b/VERSION
@@ -1 +1 @@
-0.3.3
+0.4.0
diff --git a/web/app/models/OpenTsdbQueryResult.scala b/web/app/models/OpenTsdbQueryResult.scala
@@ -42,7 +42,7 @@ case class TsdbQueryResult(
       mapping <- metric.query.mappings.find(_.subQuery == subQuery)
       tags <- mergeTags(mapping.prometheusTags)
       dp <- latestDataPoint
-    } yield PrometheusMetric(metric.name, metric.description, metric.metricType, tags, dp.value)
+    } yield PrometheusMetric(metric.name, metric.description, metric.metricType, TsdbQueryResult.sanitizeTags(tags), dp.value)
   }
 }
 
@@ -100,4 +100,11 @@ object TsdbQueryResult {
         subQuery = query
       )
   )
+
+  def sanitizeTags(prometheusTags: Map[String, String]): Map[String, String] = {
+    def sanitizeTagName(label: String): String = label
+      .replaceFirst("^[^\\p{L}_:]", ":")
+      .replaceAll("[^\\p{L}0-9_:]+", "_")
+    prometheusTags.map { case (key, value) => (sanitizeTagName(key), value) }
+  }
 }
diff --git a/web/test/MetricsControllerSpec.scala b/web/test/MetricsControllerSpec.scala
@@ -78,10 +78,10 @@ class MetricsControllerSpec extends PlaySpec
         output must contain theSameElementsInOrderAs List(
           "# HELP test_app_metrics_one TestApp metrics: one",
           "# TYPE test_app_metrics_one counter",
-          """test_app_metrics_one{severity="critical",escalation="pagerduty",role="developer"} 15.0""",
+          """test_app_metrics_one{severity="critical",escalation="pagerduty",user_role="developer"} 15.0""",
           "# HELP test_app_metrics_two TestApp metrics: two",
           "# TYPE test_app_metrics_two counter",
-          """test_app_metrics_two{severity="critical",escalation="pagerduty",role="developer"} 10.0"""
+          """test_app_metrics_two{severity="critical",escalation="pagerduty",user_role="developer"} 10.0"""
         )
       }
     }
@@ -96,7 +96,7 @@ class SimpleOpenTsdbWSMock extends OpenTsdbWSMock {
         |  {
         |    "metric": "test.app.metrics.one",
         |    "tags": {
-        |      "role": "developer"
+        |      "user.role": "developer"
         |    },
         |    "aggregateTags": [],
         |    "query": {
@@ -107,15 +107,15 @@ class SimpleOpenTsdbWSMock extends OpenTsdbWSMock {
         |      "rate": false,
         |      "filters": [
         |        {
-        |          "tagk": "role",
+        |          "tagk": "user.role",
         |          "filter": "developer",
         |          "group_by": true,
         |          "type": "literal_or"
         |        }
         |      ],
         |      "rateOptions": null,
         |      "tags": {
-        |        "role": "literal_or(developer)"
+        |        "user.role": "literal_or(developer)"
         |      }
         |    },
         |    "dps": {
@@ -139,7 +139,7 @@ class SimpleOpenTsdbWSMock extends OpenTsdbWSMock {
         |  {
         |    "metric": "test.app.metrics.two",
         |    "tags": {
-        |      "role": "developer"
+        |      "user.role": "developer"
         |    },
         |    "aggregateTags": [],
         |    "query": {
@@ -150,15 +150,15 @@ class SimpleOpenTsdbWSMock extends OpenTsdbWSMock {
         |      "rate": false,
         |      "filters": [
         |        {
-        |          "tagk": "role",
+        |          "tagk": "user.role",
         |          "filter": "developer",
         |          "group_by": true,
         |          "type": "literal_or"
         |        }
         |      ],
         |      "rateOptions": null,
         |      "tags": {
-        |        "role": "literal_or(developer)"
+        |        "user.role": "literal_or(developer)"
         |      }
         |    },
         |    "dps": {

diff --git a/web/test/data/test.app.metrics.one.json b/web/test/data/test.app.metrics.one.json
@@ -15,7 +15,7 @@
             "aggregator": "avg",
             "rate": false,
             "tags": {
-              "role": "developer"
+              "user.role": "developer"
             }
           },
           "prometheusTags": {

diff --git a/web/test/data/test.app.metrics.two.json b/web/test/data/test.app.metrics.two.json
@@ -15,7 +15,7 @@
             "aggregator": "avg",
             "rate": false,
             "tags": {
-              "role": "developer"
+              "user.role": "developer"
             }
           },
           "prometheusTags": {
@@ -29,7 +29,7 @@
             "aggregator": "avg",
             "rate": false,
             "tags": {
-              "role": "developer"
+              "user.role": "developer"
             }
           },
           "prometheusTags": {

diff --git a/web/test/models/OpenTsdbQueryResultSpec.scala b/web/test/models/OpenTsdbQueryResultSpec.scala
@@ -0,0 +1,15 @@
+package models
+
+import org.scalatestplus.play.PlaySpec
+
+class OpenTsdbQueryResultSpec extends PlaySpec {
+
+  "OpenTsdbQueryResult" should {
+    "Santize tag names" in {
+      val inputs = Map("abCD" -> "1", "123abc" -> "2", "@email" -> "3", "Unic\u00F6de" -> "4", "teach.me" -> "5")
+      val expected = Map("abCD" -> "1", ":23abc" -> "2", ":email" -> "3", "Unic\u00F6de" -> "4", "teach_me" -> "5")
+      TsdbQueryResult.sanitizeTags(inputs) must contain theSameElementsAs expected
+    }
+  }
+
+}