Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/postgresql/postgresql.go

@@ -0,0 +1,166 @@
+//go:generate ../../../tools/readme_config_includer/generator
+package postgresql
+
+import (
+	"bytes"
+	"database/sql"
+	_ "embed"
+	"fmt"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/common/postgresql"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+//go:embed sample.conf
+var sampleConfig string
+
+var ignoredColumns = map[string]bool{"stats_reset": true}
+
+type Postgresql struct {
+	Databases          []string `toml:"databases"`
+	IgnoredDatabases   []string `toml:"ignored_databases"`
+	PreparedStatements bool     `toml:"prepared_statements"`
+	postgresql.Config
+
+	service *postgresql.Service
+}
+
+func (*Postgresql) SampleConfig() string {
+	return sampleConfig
+}
+
+func (p *Postgresql) Init() error {
+	p.IsPgBouncer = !p.PreparedStatements
+
+	service, err := p.Config.CreateService()
+	if err != nil {
+		return err
+	}
+	p.service = service
+
+	return nil
+}
+
+func (p *Postgresql) Start(_ telegraf.Accumulator) error {
+	return p.service.Start()
+}
+
+func (p *Postgresql) Gather(acc telegraf.Accumulator) error {
+	var query string
+	if len(p.Databases) == 0 && len(p.IgnoredDatabases) == 0 {
+		query = `SELECT * FROM pg_stat_database`
+	} else if len(p.IgnoredDatabases) != 0 {
+		query = fmt.Sprintf(`SELECT * FROM pg_stat_database WHERE datname NOT IN ('%s')`,
+			strings.Join(p.IgnoredDatabases, "','"))
+	} else {
+		query = fmt.Sprintf(`SELECT * FROM pg_stat_database WHERE datname IN ('%s')`,
+			strings.Join(p.Databases, "','"))
+	}
+
+	rows, err := p.service.DB.Query(query)
+	if err != nil {
+		return err
+	}
+
+	defer rows.Close()
+
+	// grab the column information from the result
+	columns, err := rows.Columns()
+	if err != nil {
+		return err
+	}
+
+	for rows.Next() {
+		err = p.accRow(rows, acc, columns)
+		if err != nil {
+			return err
+		}
+	}
+
+	query = `SELECT * FROM pg_stat_bgwriter`
+
+	bgWriterRow, err := p.service.DB.Query(query)
+	if err != nil {
+		return err
+	}
+
+	defer bgWriterRow.Close()
+
+	// grab the column information from the result
+	if columns, err = bgWriterRow.Columns(); err != nil {
+		return err
+	}
+
+	for bgWriterRow.Next() {
+		if err := p.accRow(bgWriterRow, acc, columns); err != nil {
+			return err
+		}
+	}
+
+	return bgWriterRow.Err()
+}
+
+func (p *Postgresql) Stop() {
+	p.service.Stop()
+}
+
+func (p *Postgresql) accRow(row *sql.Rows, acc telegraf.Accumulator, columns []string) error {
+	var dbname bytes.Buffer
+
+	// this is where we'll store the column name with its *interface{}
+	columnMap := make(map[string]*interface{})
+
+	for _, column := range columns {
+		columnMap[column] = new(interface{})
+	}
+
+	columnVars := make([]interface{}, 0, len(columnMap))
+	// populate the array of interface{} with the pointers in the right order
+	for i := 0; i < len(columnMap); i++ {
+		columnVars = append(columnVars, columnMap[columns[i]])
+	}
+
+	// deconstruct array of variables and send to Scan
+	if err := row.Scan(columnVars...); err != nil {
+		return err
+	}
+	if columnMap["datname"] != nil {
+		// extract the database name from the column map
+		if dbNameStr, ok := (*columnMap["datname"]).(string); ok {
+			dbname.WriteString(dbNameStr)
+		} else {
+			// PG 12 adds tracking of global objects to pg_stat_database
+			dbname.WriteString("postgres_global")
+		}
+	} else {
+		dbname.WriteString(p.service.ConnectionDatabase)
+	}
+
+	tagAddress := p.service.SanitizedAddress
+	tags := map[string]string{"server": tagAddress, "db": dbname.String()}
+
+	fields := make(map[string]interface{})
+	for col, val := range columnMap {
+		_, ignore := ignoredColumns[col]
+		if !ignore {
+			fields[col] = *val
+		}
+	}
+	acc.AddFields("postgresql", fields, tags)
+
+	return nil
+}
+
+func init() {
+	inputs.Add("postgresql", func() telegraf.Input {
+		return &Postgresql{
+			Config: postgresql.Config{
+				MaxIdle: 1,
+				MaxOpen: 1,
+			},
+			PreparedStatements: true,
+		}
+	})
+}