feat: add migrate database from a source to a target databse

fix: gpg encrypt permission warning message, update Kubernetes deployment example

pkg/var.go

@@ -4,16 +4,12 @@ const cronLogFile = "/var/log/mysql-bkup.log"
 const tmpPath = "/tmp/backup"
 const backupCronFile = "/usr/local/bin/backup_cron.sh"
 const algorithm = "aes256"
+const gpgHome = "gnupg"
 const gpgExtension = "gpg"
 
 var (
 	storage            = "local"
 	file               = ""
-	dbPassword         = ""
-	dbUserName         = ""
-	dbName             = ""
-	dbHost             = ""
-	dbPort             = "3306"
 	executionMode      = "default"
 	storagePath        = "/backup"
 	disableCompression = false
@@ -27,6 +23,16 @@ var dbHVars = []string{
 	"DB_USERNAME",
 	"DB_NAME",
 }
+var sdbRVars = []string{
+	"SOURCE_DB_HOST",
+	"SOURCE_DB_PORT",
+	"SOURCE_DB_NAME",
+	"SOURCE_DB_USERNAME",
+	"SOURCE_DB_PASSWORD",
+}
+
+var dbConf *dbConfig
+var sDbConf *dbSourceConfig
 
 // sshHVars Required environment variables for SSH remote server storage
 var sshHVars = []string{