Add Application Name to PostgreSQL Connection String (#1451)

* Add Application Name to PostgreSQL Connection String,
if not existing already

* Relocate Check

* Handle Application Name only for Postgres

* URL Encode

* Relocate Function into pgutil

* Fix Error, when ApplicationName is set

* Rename parameter

* Rename Check Value

* Straightline Comment

* Remove fmt Dependency

* Fix Linting Recommendation

internal/dbutil/pgutil/db.go

@@ -5,6 +5,7 @@ package pgutil
 
 import (
 	"database/sql"
+	"strings"
 
 	"github.com/zeebo/errs"
 
@@ -98,3 +99,17 @@ func QuerySnapshot(db dbschema.Queryer) (*dbschema.Snapshot, error) {
 		Data:    data,
 	}, err
 }
+
+//CheckApplicationName ensures that the Connection String contains an application name
+func CheckApplicationName(s string) (r string) {
+	if !strings.Contains(s, "application_name") {
+		if !strings.Contains(s, "?") {
+			r = s + "?application_name=Satellite"
+			return
+		}
+		r = s + "&application_name=Satellite"
+		return
+	}
+	//return source as is if application_name is set
+	return s
+}

satellite/satellitedb/database.go

@@ -41,7 +41,9 @@ func New(log *zap.Logger, databaseURL string) (satellite.DB, error) {
 	if err != nil {
 		return nil, err
 	}
-
+	if driver == "postgres" {
+		source = pgutil.CheckApplicationName(source)
+	}
 	db, err := dbx.Open(driver, source)
 	if err != nil {
 		return nil, Error.New("failed opening database %q, %q: %v",