// validate the config object
func validateConfig(backupConfig config.Config, driver *btrfs.Btrfs) error {
// check to see if subvolume exists
// do other sanity checks
err := driver.Prepare(backupConfig)
if err != nil {
return err
}
// make sure that port number makes sense
err = fmt.Errorf("Invalid port number: %d", backupConfig.DestinationPort)
if backupConfig.DestinationPort > 65535 || backupConfig.DestinationPort < 1024 {
return err
}
// do initial testing of system by listing subvolumes
// and perform an initial snapshot for purposes of use later
subvols, err := driver.Subvolumes(backupConfig)
if err != nil && subvols == nil {
return err
}
_, err2 := driver.Snapshot(backupConfig, "/")
if err2 != nil {
return err2
}
return nil
}
// Do the majority of the application work,
// spawn off backup jobs, the like
//
// returns exit status for program
func process() error {
// parse command line args
subvolume_source := flag.String("subvolume", config.DefaultConfig().SubvolumePath, "Subvolume to back up.")
subvolume_destination_directory := flag.String("destination_subvolume", config.DefaultConfig().SubvolumeDirectoryPath,
"A relative path off of the subvolume path that will come to store snapshots.")
server := flag.Bool("server", config.DefaultConfig().Server, "Whether to enable listening as a backup server.")
destination_host := flag.String("host", config.DefaultConfig().DestinationHost, "Host to send backups to.")
destination_port := flag.Int("port", config.DefaultConfig().DestinationPort,
"TCP port of host to send backups to. "+
"Will also be the port to listen on in server mode.")
flag.Parse()
// header info
info()
// set backup configuration
backupConfig := config.Config{*subvolume_source, *subvolume_destination_directory, *server, *destination_host, *destination_port}
// create drivers
btrfs_driver := new(btrfs.Btrfs)
btrfs_driver.BackupConfig = backupConfig
// validate
err := validateConfig(backupConfig, btrfs_driver)
if err != nil {
return err
}
// start server if asked
RPC := new(btrfs.BtrfsRPC)
RPC.Driver = btrfs_driver
if backupConfig.Server {
rpc.Register(RPC)
rpc.HandleHTTP()
l, e := net.Listen("tcp", ":1234")
if e != nil {
log.Fatal("listen error:", e)
}
http.Serve(l, nil)
} else {
// otherwise we are a client. Query the client for a list of snapshots to send!
client, err := rpc.DialHTTP("tcp", backupConfig.DestinationHost+":"+string(backupConfig.DestinationPort))
if err != nil {
log.Fatal("dialing:", err)
}
// Synchronous call
subvols, err := btrfs_driver.Subvolumes(backupConfig)
args := btrfs.Args{subvols}
var reply []string
err = client.Call("BtrfsRPC.SnapshotsNeeded", args, &reply)
if err != nil {
log.Fatal("arith error:", err)
}
for i := 0; i < len(subvols); i++ {
// Send all missing snapshots to other server
// tell the other side to start receiving first
btrfs_driver.SendSubvolume(subvols[i])
}
}
return nil
}