Update approach to not require another binary to run vtshovel

Signed-off-by: Rafael Chacon <rafael@slack-corp.com>

go/vt/dbconfigs/dbconfigs.go

@@ -69,14 +69,15 @@ const (
  // AllPrivs user should have more privileges than App (should include possibility to do
  // schema changes and write to internal Vitess tables), but it shouldn't have SUPER
  // privilege like Dba has.
- AllPrivs = "allprivs"
- Dba = "dba"
- Filtered = "filtered"
- Repl = "repl"
+ AllPrivs = "allprivs"
+ Dba = "dba"
+ Filtered = "filtered"
+ Repl = "repl"
+ ExternalRepl = "erepl"
 )
 
 // All can be used to register all flags: RegisterFlags(All...)
-var All = []string{App, AppDebug, AllPrivs, Dba, Filtered, Repl}
+var All = []string{App, AppDebug, AllPrivs, Dba, Filtered, Repl, ExternalRepl}
 
 // RegisterFlags registers the flags for the given DBConfigFlag.
 // For instance, vttablet will register client, dba and repl.
@@ -157,16 +158,26 @@ func (dbcfgs *DBConfigs) DbaWithDB() *mysql.ConnParams {
  return dbcfgs.makeParams(Dba, true)
 }
 
-// FilteredWithDB returns connection parameters for appdebug with dbname set.
+// FilteredWithDB returns connection parameters for filtered with dbname set.
 func (dbcfgs *DBConfigs) FilteredWithDB() *mysql.ConnParams {
  return dbcfgs.makeParams(Filtered, true)
 }
 
-// Repl returns connection parameters for appdebug with no dbname set.
+// Repl returns connection parameters for repl with no dbname set.
 func (dbcfgs *DBConfigs) Repl() *mysql.ConnParams {
  return dbcfgs.makeParams(Repl, false)
 }
 
+// ExternalRepl returns connection parameters for repl with no dbname set.
+func (dbcfgs *DBConfigs) ExternalRepl() *mysql.ConnParams {
+ return dbcfgs.makeParams(Repl, false)
+}
+
+// ExternalReplWithDb returns connection parameters for repl with dbname set.
+func (dbcfgs *DBConfigs) ExternalReplWithDb() *mysql.ConnParams {
+ return dbcfgs.makeParams(Repl, true)
+}
+
 // AppWithDB returns connection parameters for app with dbname set.
 func (dbcfgs *DBConfigs) makeParams(userKey string, withDB bool) *mysql.ConnParams {
  orig := dbcfgs.userConfigs[userKey]