// Atomic deploy by symlink
// 1. rsync maindir => backupdir
// 2. mv -T backuplink destdir
// 3. rsync srcdir => maindir
// 4. mv -T mainlink destdir
func DeployWithSymlink(srcDir, destDir string) error {
mainLink := destDir + ".drootmain"
backupLink := destDir + ".drootbackup"
mainDir := destDir + ".d/main"
backupDir := destDir + ".d/backup"
for _, dir := range []string{mainDir, backupDir} {
if err := fileutils.CreateIfNotExists(dir, true); err != nil { // mkdir -p
return fmt.Errorf("Failed to create directory %s: %s", dir, err)
}
}
// Return error if the working directory that droot internally uses exists
for _, link := range []string{mainLink, backupLink, destDir} {
if !osutil.IsSymlink(link) && (osutil.ExistsFile(link) || osutil.ExistsDir(link)) {
return fmt.Errorf("%s already exists. Please use another directory as --dest option or delete %s", link, link)
}
}
if err := osutil.Symlink(mainDir, mainLink); err != nil {
return fmt.Errorf("Failed to create symlink %s: %s", mainLink, err)
}
if err := osutil.Symlink(backupDir, backupLink); err != nil {
return fmt.Errorf("Failed to create symlink %s: %s", backupLink, err)
}
log.Info("-->", "Syncing", "from", mainDir, "to", backupDir)
if err := Rsync(mainDir, backupDir); err != nil {
return fmt.Errorf("Failed to rsync: %s", err)
}
log.Info("-->", "Renaming", "from", backupLink, "to", destDir)
if err := os.Rename(backupLink, destDir); err != nil {
return fmt.Errorf("Failed to rename %s: %s", destDir, err)
}
log.Info("-->", "Syncing", "from", srcDir, "to", mainDir)
if err := Rsync(srcDir, mainDir); err != nil {
return fmt.Errorf("Failed to rsync: %s", err)
}
log.Info("-->", "Renaming", "from", mainLink, "to", destDir)
if err := os.Rename(mainLink, destDir); err != nil {
return fmt.Errorf("Failed to rename %s: %s", destDir, err)
}
return nil
}
func ResolveRootDir(dir string) (string, error) {
var err error
if !osutil.ExistsDir(dir) {
return dir, fmt.Errorf("No such directory %s:", dir)
}
dir, err = fp.Abs(dir)
if err != nil {
return dir, err
}
if osutil.IsSymlink(dir) {
dir, err = os.Readlink(dir)
if err != nil {
return dir, err
}
}
return fp.Clean(dir), nil
}