fix postgresql 'name', and 'oid' data types by switching to a driver (#1750)

that handles them properly

plugins/inputs/postgresql/postgresql.go

@@ -2,7 +2,6 @@ package postgresql
 
 import (
 	"bytes"
-	"database/sql"
 	"fmt"
 	"regexp"
 	"sort"
@@ -10,8 +9,6 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
-
-	"github.com/lib/pq"
 )
 
 type Postgresql struct {
@@ -23,7 +20,7 @@ type Postgresql struct {
 	sanitizedAddress string
 }
 
-var ignoredColumns = map[string]bool{"datid": true, "datname": true, "stats_reset": true}
+var ignoredColumns = map[string]bool{"stats_reset": true}
 
 var sampleConfig = `
   ## specify address via a url matching:
@@ -71,7 +68,7 @@ func (p *Postgresql) Gather(acc telegraf.Accumulator) error {
 		p.Address = localhost
 	}
 
-	db, err := sql.Open("postgres", p.Address)
+	db, err := Connect(p.Address)
 	if err != nil {
 		return err
 	}
@@ -149,7 +146,7 @@ var passwordKVMatcher, _ = regexp.Compile("password=\\S+ ?")
 func (p *Postgresql) SanitizedAddress() (_ string, err error) {
 	var canonicalizedAddress string
 	if strings.HasPrefix(p.Address, "postgres://") || strings.HasPrefix(p.Address, "postgresql://") {
-		canonicalizedAddress, err = pq.ParseURL(p.Address)
+		canonicalizedAddress, err = ParseURL(p.Address)
 		if err != nil {
 			return p.sanitizedAddress, err
 		}
@@ -185,10 +182,7 @@ func (p *Postgresql) accRow(row scanner, acc telegraf.Accumulator) error {
 	}
 	if columnMap["datname"] != nil {
 		// extract the database name from the column map
-		dbnameChars := (*columnMap["datname"]).([]uint8)
-		for i := 0; i < len(dbnameChars); i++ {
-			dbname.WriteString(string(dbnameChars[i]))
-		}
+		dbname.WriteString((*columnMap["datname"]).(string))
 	} else {
 		dbname.WriteString("postgres")
 	}