Add postgresql plugin

plugins/postgresql/postgresql.go

@@ -0,0 +1,119 @@
+package postgresql
+
+import (
+	"database/sql"
+
+	"github.com/influxdb/tivan/plugins"
+
+	_ "github.com/lib/pq"
+)
+
+type Server struct {
+	Address   string
+	Databases []string
+}
+
+type Postgresql struct {
+	Servers []*Server
+}
+
+func (p *Postgresql) Gather(acc plugins.Accumulator) error {
+	for _, serv := range p.Servers {
+		err := p.gatherServer(serv, acc)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (p *Postgresql) gatherServer(serv *Server, acc plugins.Accumulator) error {
+	db, err := sql.Open("postgres", serv.Address)
+	if err != nil {
+		return err
+	}
+
+	defer db.Close()
+
+	if len(serv.Databases) == 0 {
+		rows, err := db.Query(`SELECT * FROM pg_stat_database`)
+		if err != nil {
+			return err
+		}
+
+		defer rows.Close()
+
+		for rows.Next() {
+			err := p.accRow(rows, acc)
+			if err != nil {
+				return err
+			}
+		}
+
+		return rows.Err()
+	} else {
+		for _, name := range serv.Databases {
+			row := db.QueryRow(`SELECT * FROM pg_stat_database WHERE datname=$1`, name)
+
+			err := p.accRow(row, acc)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+type scanner interface {
+	Scan(dest ...interface{}) error
+}
+
+func (p *Postgresql) accRow(row scanner, acc plugins.Accumulator) error {
+	var ignore interface{}
+	var name string
+	var commit, rollback, read, hit int64
+	var returned, fetched, inserted, updated, deleted int64
+	var conflicts, temp_files, temp_bytes, deadlocks int64
+	var read_time, write_time float64
+
+	err := row.Scan(&ignore, &name, &ignore,
+		&commit, &rollback,
+		&read, &hit,
+		&returned, &fetched, &inserted, &updated, &deleted,
+		&conflicts, &temp_files, &temp_bytes,
+		&deadlocks, &read_time, &write_time,
+		&ignore,
+	)
+
+	if err != nil {
+		return err
+	}
+
+	tags := map[string]string{"db": name}
+
+	acc.Add("postgresql_xact_commit", commit, tags)
+	acc.Add("postgresql_xact_rollback", rollback, tags)
+	acc.Add("postgresql_blks_read", read, tags)
+	acc.Add("postgresql_blks_hit", hit, tags)
+	acc.Add("postgresql_tup_returned", returned, tags)
+	acc.Add("postgresql_tup_fetched", fetched, tags)
+	acc.Add("postgresql_tup_inserted", inserted, tags)
+	acc.Add("postgresql_tup_updated", updated, tags)
+	acc.Add("postgresql_tup_deleted", deleted, tags)
+	acc.Add("postgresql_conflicts", conflicts, tags)
+	acc.Add("postgresql_temp_files", temp_files, tags)
+	acc.Add("postgresql_temp_bytes", temp_bytes, tags)
+	acc.Add("postgresql_deadlocks", deadlocks, tags)
+	acc.Add("postgresql_blk_read_time", read_time, tags)
+	acc.Add("postgresql_blk_write_time", read_time, tags)
+
+	return nil
+}
+
+func init() {
+	plugins.Add("postgresql", func() plugins.Plugin {
+		return &Postgresql{}
+	})
+}