Move queries from queries.yaml to collectors

collector/collector.go

@@ -39,8 +39,8 @@ const (
 	// Namespace for all metrics.
 	namespace = "pg"
 
-	defaultEnabled = true
-	// defaultDisabled = false
+	defaultEnabled  = true
+	defaultDisabled = false
 )
 
 var (

collector/collector_test.go

@@ -0,0 +1,56 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed 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 collector
+
+import (
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+)
+
+type labelMap map[string]string
+
+type MetricResult struct {
+	labels     labelMap
+	value      float64
+	metricType dto.MetricType
+}
+
+func readMetric(m prometheus.Metric) MetricResult {
+	pb := &dto.Metric{}
+	m.Write(pb)
+	labels := make(labelMap, len(pb.Label))
+	for _, v := range pb.Label {
+		labels[v.GetName()] = v.GetValue()
+	}
+	if pb.Gauge != nil {
+		return MetricResult{labels: labels, value: pb.GetGauge().GetValue(), metricType: dto.MetricType_GAUGE}
+	}
+	if pb.Counter != nil {
+		return MetricResult{labels: labels, value: pb.GetCounter().GetValue(), metricType: dto.MetricType_COUNTER}
+	}
+	if pb.Untyped != nil {
+		return MetricResult{labels: labels, value: pb.GetUntyped().GetValue(), metricType: dto.MetricType_UNTYPED}
+	}
+	panic("Unsupported metric type")
+}
+
+func sanitizeQuery(q string) string {
+	q = strings.Join(strings.Fields(q), " ")
+	q = strings.Replace(q, "(", "\\(", -1)
+	q = strings.Replace(q, ")", "\\)", -1)
+	q = strings.Replace(q, "*", "\\*", -1)
+	q = strings.Replace(q, "$", "\\$", -1)
+	return q
+}

collector/pg_database.go

@@ -41,10 +41,15 @@ func NewPGDatabaseCollector(config collectorConfig) (Collector, error) {
 	}, nil
 }
 
-var pgDatabaseSizeDesc = prometheus.NewDesc(
-	"pg_database_size_bytes",
-	"Disk space used by the database",
-	[]string{"datname"}, nil,
+var (
+	pgDatabaseSizeDesc = prometheus.NewDesc(
+		"pg_database_size_bytes",
+		"Disk space used by the database",
+		[]string{"datname"}, nil,
+	)
+
+	pgDatabaseQuery     = "SELECT pg_database.datname FROM pg_database;"
+	pgDatabaseSizeQuery = "SELECT pg_database_size($1)"
 )
 
 // Update implements Collector and exposes database size.
@@ -58,9 +63,7 @@ var pgDatabaseSizeDesc = prometheus.NewDesc(
 func (c PGDatabaseCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	// Query the list of databases
 	rows, err := db.QueryContext(ctx,
-		`SELECT pg_database.datname
-		FROM pg_database;
-		`,
+		pgDatabaseQuery,
 	)
 	if err != nil {
 		return err
@@ -88,7 +91,7 @@ func (c PGDatabaseCollector) Update(ctx context.Context, db *sql.DB, ch chan<- p
 	// Query the size of the databases
 	for _, datname := range databases {
 		var size int64
-		err = db.QueryRowContext(ctx, "SELECT pg_database_size($1)", datname).Scan(&size)
+		err = db.QueryRowContext(ctx, pgDatabaseSizeQuery, datname).Scan(&size)
 		if err != nil {
 			return err
 		}

collector/pg_database_test.go

@@ -0,0 +1,59 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed 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 collector
+
+import (
+	"context"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/smartystreets/goconvey/convey"
+)
+
+func TestPGDatabaseCollector(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("Error opening a stub db connection: %s", err)
+	}
+	defer db.Close()
+
+	mock.ExpectQuery(sanitizeQuery(pgDatabaseQuery)).WillReturnRows(sqlmock.NewRows([]string{"datname"}).
+		AddRow("postgres"))
+
+	mock.ExpectQuery(sanitizeQuery(pgDatabaseSizeQuery)).WithArgs("postgres").WillReturnRows(sqlmock.NewRows([]string{"pg_database_size"}).
+		AddRow(1024))
+
+	ch := make(chan prometheus.Metric)
+	go func() {
+		defer close(ch)
+		c := PGDatabaseCollector{}
+		if err := c.Update(context.Background(), db, ch); err != nil {
+			t.Errorf("Error calling PGDatabaseCollector.Update: %s", err)
+		}
+	}()
+
+	expected := []MetricResult{
+		{labels: labelMap{"datname": "postgres"}, value: 1024, metricType: dto.MetricType_GAUGE},
+	}
+	convey.Convey("Metrics comparison", t, func() {
+		for _, expect := range expected {
+			m := readMetric(<-ch)
+			convey.So(expect, convey.ShouldResemble, m)
+		}
+	})
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled exceptions: %s", err)
+	}
+}

collector/pg_postmaster.go

@@ -0,0 +1,58 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed 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 collector
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func init() {
+	registerCollector("postmaster", defaultEnabled, NewPGPostmasterCollector)
+}
+
+type PGPostmasterCollector struct {
+}
+
+func NewPGPostmasterCollector(collectorConfig) (Collector, error) {
+	return &PGPostmasterCollector{}, nil
+}
+
+var (
+	pgPostMasterStartTimeSeconds = prometheus.NewDesc(
+		"pg_postmaster_start_time_seconds",
+		"Time at which postmaster started",
+		[]string{}, nil,
+	)
+
+	pgPostmasterQuery = "SELECT pg_postmaster_start_time from pg_postmaster_start_time();"
+)
+
+func (c *PGPostmasterCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
+	row := db.QueryRowContext(ctx,
+		pgPostmasterQuery)
+
+	var startTimeSeconds float64
+	err := row.Scan(&startTimeSeconds)
+	if err != nil {
+		return err
+	}
+	ch <- prometheus.MustNewConstMetric(
+		pgPostMasterStartTimeSeconds,
+		prometheus.GaugeValue, startTimeSeconds,
+	)
+	return nil
+}

collector/pg_postmaster_test.go

@@ -0,0 +1,57 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed 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 collector
+
+import (
+	"context"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/smartystreets/goconvey/convey"
+)
+
+func TestPgPostmasterCollector(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("Error opening a stub db connection: %s", err)
+	}
+	defer db.Close()
+
+	mock.ExpectQuery(sanitizeQuery(pgPostmasterQuery)).WillReturnRows(sqlmock.NewRows([]string{"pg_postmaster_start_time"}).
+		AddRow(1685739904))
+
+	ch := make(chan prometheus.Metric)
+	go func() {
+		defer close(ch)
+		c := PGPostmasterCollector{}
+
+		if err := c.Update(context.Background(), db, ch); err != nil {
+			t.Errorf("Error calling PGPostmasterCollector.Update: %s", err)
+		}
+	}()
+
+	expected := []MetricResult{
+		{labels: labelMap{}, value: 1685739904, metricType: dto.MetricType_GAUGE},
+	}
+	convey.Convey("Metrics comparison", t, func() {
+		for _, expect := range expected {
+			m := readMetric(<-ch)
+			convey.So(expect, convey.ShouldResemble, m)
+		}
+	})
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled exceptions: %s", err)
+	}
+}

collector/pg_process_idle.go

@@ -0,0 +1,106 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed 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 collector
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func init() {
+	registerCollector("statements", defaultEnabled, NewPGProcessIdleCollector)
+}
+
+type PGProcessIdleCollector struct {
+	log log.Logger
+}
+
+const processIdleSubsystem = "process_idle"
+
+func NewPGProcessIdleCollector(config collectorConfig) (Collector, error) {
+	return &PGProcessIdleCollector{log: config.logger}, nil
+}
+
+var pgProcessIdleSeconds = prometheus.NewDesc(
+	prometheus.BuildFQName(namespace, processIdleSubsystem, "seconds"),
+	"Idle time of server processes",
+	[]string{"application_name"},
+	prometheus.Labels{},
+)
+
+func (PGProcessIdleCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
+	row := db.QueryRowContext(ctx,
+		`WITH
+			metrics AS (
+				SELECT
+				application_name,
+				SUM(EXTRACT(EPOCH FROM (CURRENT_TIMESTAMP - state_change))::bigint)::float AS process_idle_seconds_sum,
+				COUNT(*) AS process_idle_seconds_count
+				FROM pg_stat_activity
+				WHERE state = 'idle'
+				GROUP BY application_name
+			),
+			buckets AS (
+				SELECT
+				application_name,
+				le,
+				SUM(
+					CASE WHEN EXTRACT(EPOCH FROM (CURRENT_TIMESTAMP - state_change)) <= le
+					THEN 1
+					ELSE 0
+					END
+				)::bigint AS bucket
+				FROM
+				pg_stat_activity,
+				UNNEST(ARRAY[1, 2, 5, 15, 30, 60, 90, 120, 300]) AS le
+				GROUP BY application_name, le
+				ORDER BY application_name, le
+			)
+			SELECT
+			application_name,
+			process_idle_seconds_sum as seconds_sum,
+			process_idle_seconds_count as seconds_count,
+			ARRAY_AGG(le) AS seconds,
+			ARRAY_AGG(bucket) AS seconds_bucket
+			FROM metrics JOIN buckets USING (application_name)
+			GROUP BY 1, 2, 3;`)
+
+	var applicationName string
+	var secondsSum int64
+	var secondsCount uint64
+	var seconds []int64
+	var secondsBucket []uint64
+
+	err := row.Scan(&applicationName, &secondsSum, &secondsCount, &seconds, &secondsBucket)
+
+	var buckets = make(map[float64]uint64, len(seconds))
+	for i, second := range seconds {
+		if i >= len(secondsBucket) {
+			break
+		}
+		buckets[float64(second)] = secondsBucket[i]
+	}
+	if err != nil {
+		return err
+	}
+	ch <- prometheus.MustNewConstHistogram(
+		pgProcessIdleSeconds,
+		secondsCount, float64(secondsSum), buckets,
+		applicationName,
+	)
+	return nil
+}