1 files changed, 170 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/modules/postgres/postgres.go b/src/go/collectors/go.d.plugin/modules/postgres/postgres.go
new file mode 100644
index 000000000..670cd0b08
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/modules/postgres/postgres.go
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package postgres
+
+import (
+	"database/sql"
+	_ "embed"
+	"errors"
+	"sync"
+	"time"
+
+	"github.com/netdata/netdata/go/go.d.plugin/agent/module"
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/matcher"
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/metrics"
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/web"
+
+	"github.com/jackc/pgx/v4/stdlib"
+	_ "github.com/jackc/pgx/v4/stdlib"
+)
+
+//go:embed "config_schema.json"
+var configSchema string
+
+func init() {
+	module.Register("postgres", module.Creator{
+		JobConfigSchema: configSchema,
+		Create:          func() module.Module { return New() },
+	})
+}
+
+func New() *Postgres {
+	return &Postgres{
+		Config: Config{
+			Timeout:            web.Duration(time.Second * 2),
+			DSN:                "postgres://postgres:postgres@127.0.0.1:5432/postgres",
+			XactTimeHistogram:  []float64{.1, .5, 1, 2.5, 5, 10},
+			QueryTimeHistogram: []float64{.1, .5, 1, 2.5, 5, 10},
+			// charts: 20 x table, 4 x index.
+			// https://discord.com/channels/847502280503590932/1022693928874549368
+			MaxDBTables:  50,
+			MaxDBIndexes: 250,
+		},
+		charts:  baseCharts.Copy(),
+		dbConns: make(map[string]*dbConn),
+		mx: &pgMetrics{
+			dbs:       make(map[string]*dbMetrics),
+			indexes:   make(map[string]*indexMetrics),
+			tables:    make(map[string]*tableMetrics),
+			replApps:  make(map[string]*replStandbyAppMetrics),
+			replSlots: make(map[string]*replSlotMetrics),
+		},
+		recheckSettingsEvery:              time.Minute * 30,
+		doSlowEvery:                       time.Minute * 5,
+		addXactQueryRunningTimeChartsOnce: &sync.Once{},
+		addWALFilesChartsOnce:             &sync.Once{},
+	}
+}
+
+type Config struct {
+	UpdateEvery        int          `yaml:"update_every" json:"update_every"`
+	DSN                string       `yaml:"dsn" json:"dsn"`
+	Timeout            web.Duration `yaml:"timeout" json:"timeout"`
+	DBSelector         string       `yaml:"collect_databases_matching" json:"collect_databases_matching"`
+	XactTimeHistogram  []float64    `yaml:"transaction_time_histogram" json:"transaction_time_histogram"`
+	QueryTimeHistogram []float64    `yaml:"query_time_histogram" json:"query_time_histogram"`
+	MaxDBTables        int64        `yaml:"max_db_tables" json:"max_db_tables"`
+	MaxDBIndexes       int64        `yaml:"max_db_indexes" json:"max_db_indexes"`
+}
+
+type (
+	Postgres struct {
+		module.Base
+		Config `yaml:",inline" json:""`
+
+		charts                            *module.Charts
+		addXactQueryRunningTimeChartsOnce *sync.Once
+		addWALFilesChartsOnce             *sync.Once
+
+		db      *sql.DB
+		dbConns map[string]*dbConn
+
+		superUser            *bool
+		pgIsInRecovery       *bool
+		pgVersion            int
+		dbSr                 matcher.Matcher
+		recheckSettingsTime  time.Time
+		recheckSettingsEvery time.Duration
+		doSlowTime           time.Time
+		doSlowEvery          time.Duration
+
+		mx *pgMetrics
+	}
+	dbConn struct {
+		db         *sql.DB
+		connStr    string
+		connErrors int
+	}
+)
+
+func (p *Postgres) Configuration() any {
+	return p.Config
+}
+
+func (p *Postgres) Init() error {
+	err := p.validateConfig()
+	if err != nil {
+		p.Errorf("config validation: %v", err)
+		return err
+	}
+
+	sr, err := p.initDBSelector()
+	if err != nil {
+		p.Errorf("config validation: %v", err)
+		return err
+	}
+	p.dbSr = sr
+
+	p.mx.xactTimeHist = metrics.NewHistogramWithRangeBuckets(p.XactTimeHistogram)
+	p.mx.queryTimeHist = metrics.NewHistogramWithRangeBuckets(p.QueryTimeHistogram)
+
+	return nil
+}
+
+func (p *Postgres) Check() error {
+	mx, err := p.collect()
+	if err != nil {
+		p.Error(err)
+		return err
+	}
+	if len(mx) == 0 {
+		return errors.New("no metrics collected")
+	}
+	return nil
+}
+
+func (p *Postgres) Charts() *module.Charts {
+	return p.charts
+}
+
+func (p *Postgres) Collect() map[string]int64 {
+	mx, err := p.collect()
+	if err != nil {
+		p.Error(err)
+	}
+
+	if len(mx) == 0 {
+		return nil
+	}
+	return mx
+}
+
+func (p *Postgres) Cleanup() {
+	if p.db == nil {
+		return
+	}
+	if err := p.db.Close(); err != nil {
+		p.Warningf("cleanup: error on closing the Postgres database [%s]: %v", p.DSN, err)
+	}
+	p.db = nil
+
+	for dbname, conn := range p.dbConns {
+		delete(p.dbConns, dbname)
+		if conn.connStr != "" {
+			stdlib.UnregisterConnConfig(conn.connStr)
+		}
+		if conn.db != nil {
+			_ = conn.db.Close()
+		}
+	}
+}