Merge pull request #13 from form3tech-oss/ap-stmnt-summary-collector

feat: add custom collector for statement summary

Author: alessio-form3

.github/workflows/calculate-tag.yaml

@@ -34,7 +34,7 @@ jobs:
           if [[ "${{ github.ref_type }}" = "tag" ]]; then
             latest_tag="${GITHUB_REF#refs/tags/}"
           else
-            latest_tag=$(git describe --tags --abbrev=0)
+            latest_tag=$(git describe --tags --abbrev=1)
           fi
           echo "latest_tag=$latest_tag" >> $GITHUB_OUTPUT
       - name: Calculate pre-release suffix

.github/workflows/ci.yaml

@@ -38,9 +38,10 @@ jobs:
       - name: Package
         run: make crossbuild-tarballs
       - name: Archive artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: tarballs
+          include-hidden-files: true
           path: ./.tarballs/*.tar.gz
 
   commit-message:
@@ -67,7 +68,7 @@ jobs:
     if: contains(needs.commit-message.outputs.head-commit-message, 'pre-release') || startsWith(github.ref, 'refs/tags')
     steps:
       - name: Download artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: tarballs
       - name: Create GH release

.promu.yml

@@ -1,6 +1,5 @@
 go:
-    # This must match .circle/config.yml.
-    version: 1.21
+    version: 1.22
 repository:
     path: github.com/form3tech-oss/postgres_exporter
 build:

VERSION

@@ -1 +1 @@
-0.15.0
+0.15.3

cmd/postgres_exporter/main.go

@@ -14,7 +14,9 @@
 package main
 
 import (
+	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"strings"
@@ -46,6 +48,7 @@ var (
 	autoDiscoverDatabases  = kingpin.Flag("auto-discover-databases", "Whether to discover the databases on a server dynamically. (DEPRECATED)").Default("false").Envar("PG_EXPORTER_AUTO_DISCOVER_DATABASES").Bool()
 	queriesPath            = kingpin.Flag("extend.query-path", "Path to custom queries to run. (DEPRECATED)").Default("").Envar("PG_EXPORTER_EXTEND_QUERY_PATH").String()
 	onlyDumpMaps           = kingpin.Flag("dumpmaps", "Do not run, simply dump the maps.").Bool()
+	onlyHealthCheck        = kingpin.Flag("healthcheck", "Do not run, just return if up and running.").Bool()
 	constantLabelsList     = kingpin.Flag("constantLabels", "A list of label=value separated by comma(,). (DEPRECATED)").Default("").Envar("PG_EXPORTER_CONSTANT_LABELS").String()
 	excludeDatabases       = kingpin.Flag("exclude-databases", "A list of databases to remove when autoDiscoverDatabases is enabled (DEPRECATED)").Default("").Envar("PG_EXPORTER_EXCLUDE_DATABASES").String()
 	includeDatabases       = kingpin.Flag("include-databases", "A list of databases to include when autoDiscoverDatabases is enabled (DEPRECATED)").Default("").Envar("PG_EXPORTER_INCLUDE_DATABASES").String()
@@ -81,6 +84,18 @@ func main() {
 		return
 	}
 
+	if *onlyHealthCheck {
+		healthy, err := runHealthCheck(webConfig)
+		if err != nil {
+			level.Error(logger).Log("msg", "error running health check", "err", err)
+		}
+		if healthy {
+			level.Info(logger).Log("msg", "health ok")
+			os.Exit(0)
+		}
+		os.Exit(1)
+	}
+
 	if err := c.ReloadConfig(*configFile, logger); err != nil {
 		// This is not fatal, but it means that auth must be provided for every dsn.
 		level.Warn(logger).Log("msg", "Error loading config", "err", err)
@@ -122,29 +137,38 @@ func main() {
 		exporter.servers.Close()
 	}()
 
-	prometheus.MustRegister(version.NewCollector(exporterName))
+	reg := prometheus.NewRegistry()
 
-	prometheus.MustRegister(exporter)
+	reg.MustRegister(
+		version.NewCollector(exporterName),
+		exporter,
+	)
 
 	// TODO(@sysadmind): Remove this with multi-target support. We are removing multiple DSN support
 	dsn := ""
 	if len(dsns) > 0 {
 		dsn = dsns[0]
 	}
+	
+	collOpts := []collector.Option{
+		collector.WithConstantLabels(parseConstLabels(*constantLabelsList)),
+	}
 
-	pe, err := collector.NewPostgresCollector(
+	pgColl, err := collector.NewPostgresCollector(
 		logger,
 		excludedDatabases,
 		dsn,
 		[]string{},
+		collOpts...
 	)
 	if err != nil {
 		level.Warn(logger).Log("msg", "Failed to create PostgresCollector", "err", err.Error())
 	} else {
-		prometheus.MustRegister(pe)
+		
+		reg.MustRegister(pgColl)
 	}
 
-	http.Handle(*metricsPath, promhttp.Handler())
+	http.Handle(*metricsPath, promhttp.HandlerFor(reg, promhttp.HandlerOpts{}))
 
 	if *metricsPath != "/" && *metricsPath != "" {
 		landingConfig := web.LandingConfig{
@@ -174,3 +198,30 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+func runHealthCheck(webConfig *web.FlagConfig) (bool, error) {
+	if len(*webConfig.WebListenAddresses) == 0 {
+		return false, errors.New("no listen addresses to run the request to")
+	}
+	addr := (*webConfig.WebListenAddresses)[0]
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return false, err
+	}
+	if host == "" {
+		host = "localhost"
+	}
+	url := fmt.Sprintf("http://%s:%s/", host, port)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return false, err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return false, err
+	}
+
+	defer resp.Body.Close()
+	return resp.StatusCode == 200, nil
+}

cmd/postgres_exporter/postgres_exporter.go

@@ -415,7 +415,7 @@ type Exporter struct {
 	userQueriesPath  string
 	constantLabels   prometheus.Labels
 	duration         prometheus.Gauge
-	error            prometheus.Gauge
+	errors            prometheus.Gauge
 	psqlUp           prometheus.Gauge
 	userQueriesError *prometheus.GaugeVec
 	totalScrapes     prometheus.Counter
@@ -537,7 +537,7 @@ func (e *Exporter) setupInternalMetrics() {
 		Help:        "Total number of times PostgreSQL was scraped for metrics.",
 		ConstLabels: e.constantLabels,
 	})
-	e.error = prometheus.NewGauge(prometheus.GaugeOpts{
+	e.errors = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace:   namespace,
 		Subsystem:   exporter,
 		Name:        "last_scrape_error",
@@ -569,7 +569,7 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 
 	ch <- e.duration
 	ch <- e.totalScrapes
-	ch <- e.error
+	ch <- e.errors
 	ch <- e.psqlUp
 	e.userQueriesError.Collect(ch)
 }
@@ -676,6 +676,7 @@ func (e *Exporter) scrape(ch chan<- prometheus.Metric) {
 	var connectionErrorsCount int
 
 	for _, dsn := range dsns {
+		level.Debug(logger).Log("msg", "start scrape", "dsn", dsn)
 		if err := e.scrapeDSN(ch, dsn); err != nil {
 			errorsCount++
 
@@ -696,8 +697,8 @@ func (e *Exporter) scrape(ch chan<- prometheus.Metric) {
 
 	switch errorsCount {
 	case 0:
-		e.error.Set(0)
+		e.errors.Set(0)
 	default:
-		e.error.Set(1)
+		e.errors.Set(1)
 	}
 }

collector/collector.go

@@ -64,6 +64,7 @@ type Collector interface {
 type collectorConfig struct {
 	logger           log.Logger
 	excludeDatabases []string
+	constantLabels   prometheus.Labels
 }
 
 func registerCollector(name string, isDefaultEnabled bool, createFunc func(collectorConfig) (Collector, error)) {
@@ -92,10 +93,19 @@ type PostgresCollector struct {
 	logger     log.Logger
 
 	instance *instance
+	constantLabels prometheus.Labels
 }
 
 type Option func(*PostgresCollector) error
 
+// WithConstantLabels configures constant labels.
+func WithConstantLabels(l prometheus.Labels) Option {
+	return func(c *PostgresCollector) error {
+		c.constantLabels = l
+		return nil
+	}
+}
+
 // NewPostgresCollector creates a new PostgresCollector.
 func NewPostgresCollector(logger log.Logger, excludeDatabases []string, dsn string, filters []string, options ...Option) (*PostgresCollector, error) {
 	p := &PostgresCollector{
@@ -134,6 +144,7 @@ func NewPostgresCollector(logger log.Logger, excludeDatabases []string, dsn stri
 			collector, err := factories[key](collectorConfig{
 				logger:           log.With(logger, "collector", key),
 				excludeDatabases: excludeDatabases,
+				constantLabels:   p.constantLabels,
 			})
 			if err != nil {
 				return nil, err

collector/pg_database.go

@@ -30,6 +30,8 @@ func init() {
 type PGDatabaseCollector struct {
 	log               log.Logger
 	excludedDatabases []string
+	pgDatabaseSizeDesc *prometheus.Desc
+	pgDatabaseConnectionLimitsDesc *prometheus.Desc
 }
 
 func NewPGDatabaseCollector(config collectorConfig) (Collector, error) {
@@ -40,29 +42,28 @@ func NewPGDatabaseCollector(config collectorConfig) (Collector, error) {
 	return &PGDatabaseCollector{
 		log:               config.logger,
 		excludedDatabases: exclude,
+		pgDatabaseSizeDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(
+				namespace,
+				databaseSubsystem,
+				"size_bytes",
+			),
+			"Disk space used by the database",
+			[]string{"datname"}, config.constantLabels,
+		),
+		pgDatabaseConnectionLimitsDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(
+				namespace,
+				databaseSubsystem,
+				"connection_limit",
+			),
+			"Connection limit set for the database",
+			[]string{"datname"}, config.constantLabels,
+		),
 	}, nil
 }
 
 var (
-	pgDatabaseSizeDesc = prometheus.NewDesc(
-		prometheus.BuildFQName(
-			namespace,
-			databaseSubsystem,
-			"size_bytes",
-		),
-		"Disk space used by the database",
-		[]string{"datname"}, nil,
-	)
-	pgDatabaseConnectionLimitsDesc = prometheus.NewDesc(
-		prometheus.BuildFQName(
-			namespace,
-			databaseSubsystem,
-			"connection_limit",
-		),
-		"Connection limit set for the database",
-		[]string{"datname"}, nil,
-	)
-
 	pgDatabaseQuery     = "SELECT pg_database.datname, pg_database.datconnlimit FROM pg_database;"
 	pgDatabaseSizeQuery = "SELECT pg_database_size($1)"
 )
@@ -113,7 +114,7 @@ func (c PGDatabaseCollector) Update(ctx context.Context, instance *instance, ch
 			connLimitMetric = float64(connLimit.Int64)
 		}
 		ch <- prometheus.MustNewConstMetric(
-			pgDatabaseConnectionLimitsDesc,
+			c.pgDatabaseConnectionLimitsDesc,
 			prometheus.GaugeValue, connLimitMetric, database,
 		)
 	}
@@ -131,7 +132,7 @@ func (c PGDatabaseCollector) Update(ctx context.Context, instance *instance, ch
 			sizeMetric = size.Float64
 		}
 		ch <- prometheus.MustNewConstMetric(
-			pgDatabaseSizeDesc,
+			c.pgDatabaseSizeDesc,
 			prometheus.GaugeValue, sizeMetric, datname,
 		)
 

collector/pg_database_test.go

@@ -17,6 +17,7 @@ import (
 	"testing"
 
 	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
 	dto "github.com/prometheus/client_model/go"
 	"github.com/smartystreets/goconvey/convey"
@@ -40,7 +41,10 @@ func TestPGDatabaseCollector(t *testing.T) {
 	ch := make(chan prometheus.Metric)
 	go func() {
 		defer close(ch)
-		c := PGDatabaseCollector{}
+		c, _ := NewPGDatabaseCollector(collectorConfig{
+			logger: log.NewNopLogger(),
+			constantLabels: prometheus.Labels{},
+		})
 		if err := c.Update(context.Background(), inst, ch); err != nil {
 			t.Errorf("Error calling PGDatabaseCollector.Update: %s", err)
 		}
@@ -81,7 +85,10 @@ func TestPGDatabaseCollectorNullMetric(t *testing.T) {
 	ch := make(chan prometheus.Metric)
 	go func() {
 		defer close(ch)
-		c := PGDatabaseCollector{}
+		c, _ := NewPGDatabaseCollector(collectorConfig{
+			logger: log.NewNopLogger(),
+			constantLabels: prometheus.Labels{},
+		})
 		if err := c.Update(context.Background(), inst, ch); err != nil {
 			t.Errorf("Error calling PGDatabaseCollector.Update: %s", err)
 		}