Overhaul database package

perf/go/perf_migratedb/main.go

 package main
 
 // Executes database migrations to the latest target version. In production this
 // requires the root password for MySQL. The user will be prompted for that so
 // it is not entered via the command line.
 
 import (
         "bufio"
         "flag"
         "fmt"
         "os"
         "strings"
 
         "github.com/golang/glog"
         "skia.googlesource.com/buildbot.git/go/common"
         "skia.googlesource.com/buildbot.git/go/database"
         "skia.googlesource.com/buildbot.git/perf/go/db"
 )
 
 func main() {
-        common.Init()
-        defaultConnStr := strings.Replace(db.DB_CONN_TMPL, "%s", "root", 1)
+        defaultConnStr := fmt.Sprintf(database.DB_CONN_TMPL, database.USER_ROOT, "%s", db.PROD_DB_HOST, db.PROD_DB)
 
         // flags
         dbConnString := flag.String("db_conn_string", defaultConnStr, "\n\tDatabase string to open connect to the MySQL database. "+
                 "\n\tNeeds to follow the format of the golang-mysql driver (https://github.com/go-sql-driver/mysql."+
                 "\n\tIf the string contains %s the user will be prompted to enter a password which will then be used for subtitution.")
 
+        common.Init()
+
         var connectionStr = *dbConnString
 
         // if it contains formatting information read the password from stdin.
         if strings.Contains(connectionStr, "%s") {
                 glog.Infof("Using connection string: %s", connectionStr)
                 reader := bufio.NewReader(os.Stdin)
                 fmt.Print("Enter password for MySQL: ")
                 password, err := reader.ReadString('\n')
                 if err != nil {
                         glog.Fatalf("Unable to read password. Error: %s", err)
@@ skipping 20 matching lines @@
         if dbVersion < maxDBVersion {
                 glog.Infof("Migrating to version: %d", maxDBVersion)
                 err = vdb.Migrate(maxDBVersion)
                 if err != nil {
                         glog.Fatalf("Unable to retrieve database version. Error: %s", err)
                 }
         }
 
         glog.Infoln("Database migration finished.")
 }