Overhaul database package

datahopper/go/buildbot_migratedb/main.go

Index: datahopper/go/buildbot_migratedb/main.go
diff --git a/datahopper/go/buildbot_migratedb/main.go b/datahopper/go/buildbot_migratedb/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..45f8ef93462c66fa48e169e55ca8a6362bd7e1d4
--- /dev/null
+++ b/datahopper/go/buildbot_migratedb/main.go
@@ -0,0 +1,52 @@
+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 (
+	"flag"
+
+	"github.com/golang/glog"
+	"skia.googlesource.com/buildbot.git/go/buildbot"
+	"skia.googlesource.com/buildbot.git/go/common"
+	"skia.googlesource.com/buildbot.git/go/database"
+)
+
+var (
+	local = flag.Bool("local", false, "Running locally if true. As opposed to in production.")
+)
+
+func main() {
+	// Set up flags.
+	database.SetupFlags(buildbot.PROD_DB_HOST, buildbot.PROD_DB_PORT, database.USER_ROOT, buildbot.PROD_DB_NAME)
+
+	// Global init to initialize glog and parse arguments.
+	common.Init()
+
+	conf, err := database.ConfigFromFlagsAndMetadata(*local, buildbot.MigrationSteps())
+	if err != nil {
+		glog.Fatal(err)
+	}
+	vdb := database.NewVersionedDB(conf)
+
+	// Get the current database version
+	maxDBVersion := vdb.MaxDBVersion()
+	glog.Infof("Latest database version: %d", maxDBVersion)
+
+	dbVersion, err := vdb.DBVersion()
+	if err != nil {
+		glog.Fatalf("Unable to retrieve database version. Error: %s", err)
+	}
+	glog.Infof("Current database version: %d", dbVersion)
+
+	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.")
+}