Revert "PMM-10292 Remove unused collector (#547)"

This reverts commit cf4ca67.

Author: trvrnrth

exporter/serverstatus_collector.go

@@ -0,0 +1,75 @@
+// mongodb_exporter
+// Copyright (C) 2017 Percona LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package exporter
+
+import (
+	"context"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sirupsen/logrus"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+type serverStatusCollector struct {
+	ctx  context.Context
+	base *baseCollector
+
+	compatibleMode bool
+	topologyInfo   labelsGetter
+}
+
+// newServerStatusCollector creates a collector for statistics on server status.
+func newServerStatusCollector(ctx context.Context, client *mongo.Client, logger *logrus.Logger, compatible bool, topology labelsGetter) *serverStatusCollector {
+	return &serverStatusCollector{
+		ctx:            ctx,
+		base:           newBaseCollector(client, logger),
+		compatibleMode: compatible,
+		topologyInfo:   topology,
+	}
+}
+
+func (d *serverStatusCollector) Describe(ch chan<- *prometheus.Desc) {
+	d.base.Describe(d.ctx, ch, d.collect)
+}
+
+func (d *serverStatusCollector) Collect(ch chan<- prometheus.Metric) {
+	d.base.Collect(ch)
+}
+
+func (d *serverStatusCollector) collect(ch chan<- prometheus.Metric) {
+	defer prometheus.MeasureCollectTime(ch, "mongodb", "serverstatus")()
+
+	logger := d.base.logger
+	client := d.base.client
+
+	cmd := bson.D{{Key: "serverStatus", Value: "1"}}
+	res := client.Database("admin").RunCommand(d.ctx, cmd)
+
+	var m bson.M
+	if err := res.Decode(&m); err != nil {
+		ch <- prometheus.NewInvalidMetric(prometheus.NewInvalidDesc(err), err)
+		return
+	}
+
+	logger.Debug("serverStatus result:")
+	debugResult(logger, m)
+
+	for _, metric := range makeMetrics("", m, d.topologyInfo.baseLabels(), d.compatibleMode) {
+		ch <- metric
+	}
+}

exporter/serverstatus_collector_test.go

@@ -0,0 +1,60 @@
+// mongodb_exporter
+// Copyright (C) 2017 Percona LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package exporter
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus/testutil"
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/percona/mongodb_exporter/internal/tu"
+)
+
+func TestServerStatusDataCollector(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	client := tu.DefaultTestClient(ctx, t)
+
+	ti := labelsGetterMock{}
+
+	c := newServerStatusCollector(ctx, client, logrus.New(), false, ti)
+
+	// The last \n at the end of this string is important
+	expected := strings.NewReader(`
+	# HELP mongodb_mem_bits mem.
+	# TYPE mongodb_mem_bits untyped
+	mongodb_mem_bits 64
+	# HELP mongodb_metrics_commands_connPoolSync_failed metrics.commands.connPoolSync.
+	# TYPE mongodb_metrics_commands_connPoolSync_failed untyped
+	mongodb_metrics_commands_connPoolSync_failed 0` + "\n")
+	// Filter metrics for 2 reasons:
+	// 1. The result is huge
+	// 2. We need to check against know values. Don't use metrics that return counters like uptime
+	//    or counters like the number of transactions because they won't return a known value to compare
+	filter := []string{
+		"mongodb_mem_bits",
+		"mongodb_metrics_commands_connPoolSync_failed",
+	}
+	err := testutil.CollectAndCompare(c, expected, filter...)
+	assert.NoError(t, err)
+}