[Metricbeat][Kubernetes] Update kube state metrics fetched metrics

metricbeat/helper/kubernetes/ktest/ktest.go

@@ -0,0 +1,81 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package ktest
+
+import (
+	"io/ioutil"
+	"strings"
+	"testing"
+
+	p "github.com/elastic/beats/v7/metricbeat/helper/prometheus"
+	"github.com/elastic/beats/v7/metricbeat/helper/prometheus/ptest"
+)
+
+// GetTestCases Build test cases from the files and returns them
+func GetTestCases(files []string) ptest.TestCases {
+	var cases ptest.TestCases
+	for i := 0; i < len(files); i++ {
+		cases = append(cases,
+			struct {
+				MetricsFile  string
+				ExpectedFile string
+			}{
+				// the metrics file is inside the parent directory, while the expected file is in the current directory
+				// Example:
+				//	Metricsfile: ../_meta/test/ksm.v2.4.2
+				//	ExpectedFile: ./_meta/test/ksm.v2.4.2.expected
+				MetricsFile:  files[i],
+				ExpectedFile: files[i][1:] + ".expected",
+			},
+		)
+	}
+	return cases
+}
+
+// TestStateMetricsFamily
+// This function reads the metric files and checks if the resource fetched metrics exist in it.
+// It only checks the family metric, because if the metric doesn't have any data, we don't have a way
+// to know the labels from the file.
+// The test fails if the metric does not exist in any of the files.
+// A warning is printed if the metric is not present in all of them.
+// Nothing happens, otherwise.
+func TestStateMetricsFamily(t *testing.T, files []string, mapping *p.MetricsMapping) {
+	metricsFiles := map[string][]string{}
+	for i := 0; i < len(files); i++ {
+		content, err := ioutil.ReadFile(files[i])
+		if err != nil {
+			t.Fatalf("Unknown file %s.", files[i])
+		}
+		text := string(content)
+		for metric := range mapping.Metrics {
+			// A space is needed to check if the metric exists, since there are metrics that can follow this logic:
+			// some_metric and some_metric_total
+			if !strings.Contains(text, "# TYPE "+metric+" ") {
+				metricsFiles[metric] = append(metricsFiles[metric], files[i])
+			}
+		}
+	}
+	for metric, filesList := range metricsFiles {
+		if len(filesList) != len(files) {
+			t.Logf("Warning: metric %s is not present in all files.", metric)
+		} else {
+			t.Errorf("Unknown metric: %s", metric)
+		}
+	}
+
+}