prometheus: Initialize all metrics

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

docs/prometheus.md

@@ -30,7 +30,7 @@ Here is a list of the metrics we provide:
 - `mgmt_resources_total`: The number of resources that mgmt is managing
 - `mgmt_checkapply_total`: The number of CheckApply's that mgmt has run
 - `mgmt_failures_total`: The number of resources that have failed
-- `mgmt_failures_current`: The number of resources that have failed
+- `mgmt_failures`: The number of resources that have failed
 - `mgmt_graph_start_time_seconds`: Start time of the current graph since unix epoch in seconds
 
 For each metric, you will get some extra labels:

prometheus/prometheus.go

@@ -16,7 +16,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 // Package prometheus provides functions that are useful to control and manage
-// the build-in prometheus instance.
+// the built-in prometheus instance.
 package prometheus
 
 import (
@@ -170,6 +170,15 @@ func (obj *Prometheus) InitKindMetrics(kinds []string) error {
 				}
 			}
 		}
+
+		obj.managedResources.With(prometheus.Labels{"kind": kind})
+
+		failures := []string{"soft", "hard"}
+		for _, f := range failures {
+			failLabels := prometheus.Labels{"kind": kind, "failure": f}
+			obj.failedResourcesTotal.With(failLabels)
+			obj.failedResources.With(failLabels)
+		}
 	}
 	return nil
 }

prometheus/prometheus_test.go

@@ -0,0 +1,75 @@
+// Mgmt
+// Copyright (C) 2013-2017+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package prometheus
+
+import (
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// TestInitKindMetrics tests that we are initializing the Prometheus
+// metrics correctly for all kind of resources.
+func TestInitKindMetrics(t *testing.T) {
+	var prom Prometheus
+	prom.Init()
+	prom.InitKindMetrics([]string{"file", "exec"})
+
+	// Get a list of metrics collected by Prometheus.
+	// This is the only way to get Prometheus metrics
+	// without implicitly creating them.
+	gatherer := prometheus.DefaultGatherer
+	metrics, err := gatherer.Gather()
+	if err != nil {
+		t.Errorf("Error while gathering metrics: %s", err)
+		return
+	}
+
+	// expectedMetrics is a map: keys are metrics name and
+	// values are expected and actual count of metrics with
+	// that name.
+	expectedMetrics := map[string][2]int{
+		"mgmt_checkapply_total": [2]int{
+			16, 0,
+		},
+		"mgmt_failures_total": [2]int{
+			4, 0,
+		},
+		"mgmt_failures": [2]int{
+			4, 0,
+		},
+		"mgmt_resources": [2]int{
+			2, 0,
+		},
+	}
+
+	for _, metric := range metrics {
+		for name, count := range expectedMetrics {
+			if *metric.Name == name {
+				value := len(metric.Metric)
+				expectedMetrics[name] = [2]int{count[0], value}
+			}
+		}
+	}
+
+	for name, count := range expectedMetrics {
+		if count[1] != count[0] {
+			t.Errorf("%s: Expected %d metrics, got %d metrics", name, count[0], count[1])
+		}
+	}
+}