// basicEnv returns the app-level environment variables for a snap.
// Despite this being a bit snap-specific, this is in helpers.go because it's
// used by so many other modules, we run into circular dependencies if it's
// somewhere more reasonable like the snappy module.
func basicEnv(info *snap.Info) map[string]string {
return map[string]string{
"SNAP": info.MountDir(),
"SNAP_COMMON": info.CommonDataDir(),
"SNAP_DATA": info.DataDir(),
"SNAP_NAME": info.Name(),
"SNAP_VERSION": info.Version,
"SNAP_REVISION": info.Revision.String(),
"SNAP_ARCH": arch.UbuntuArchitecture(),
"SNAP_LIBRARY_PATH": "/var/lib/snapd/lib/gl:",
"SNAP_REEXEC": os.Getenv("SNAP_REEXEC"),
}
}
// resolveSpecialVariable resolves one of the three $SNAP* variables at the
// beginning of a given path. The variables are $SNAP, $SNAP_DATA and
// $SNAP_COMMON. If there are no variables then $SNAP is implicitly assumed
// (this is the behavior that was used before the variables were supporter).
func resolveSpecialVariable(path string, snapInfo *snap.Info) string {
if strings.HasPrefix(path, "$SNAP/") || path == "$SNAP" {
return strings.Replace(path, "$SNAP", snapInfo.MountDir(), 1)
}
if strings.HasPrefix(path, "$SNAP_DATA/") || path == "$SNAP_DATA" {
return strings.Replace(path, "$SNAP_DATA", snapInfo.DataDir(), 1)
}
if strings.HasPrefix(path, "$SNAP_COMMON/") || path == "$SNAP_COMMON" {
return strings.Replace(path, "$SNAP_COMMON", snapInfo.CommonDataDir(), 1)
}
// NOTE: assume $SNAP by default if nothing else is provided, for compatibility
return filepath.Join(snapInfo.MountDir(), path)
}
// CopySnapData makes a copy of oldSnap data for newSnap in its data directories.
func (b Backend) CopySnapData(newSnap, oldSnap *snap.Info, meter progress.Meter) error {
// deal with the old data or
// otherwise just create a empty data dir
// Make sure the common data directory exists, even if this isn't a new
// install.
if err := os.MkdirAll(newSnap.CommonDataDir(), 0755); err != nil {
return err
}
if oldSnap == nil {
return os.MkdirAll(newSnap.DataDir(), 0755)
}
return copySnapData(oldSnap, newSnap)
}
// Copy all data for oldSnap to newSnap
// (but never overwrite)
func copySnapData(oldSnap, newSnap *snap.Info) (err error) {
oldDataDirs, err := snapDataDirs(oldSnap)
if err != nil {
return err
}
newSuffix := filepath.Base(newSnap.DataDir())
for _, oldDir := range oldDataDirs {
// replace the trailing "../$old-suffix" with the "../$new-suffix"
newDir := filepath.Join(filepath.Dir(oldDir), newSuffix)
if err := copySnapDataDirectory(oldDir, newDir); err != nil {
return err
}
}
return nil
}
// snapDataDirs returns the list of data directories for the given snap version
func snapDataDirs(snap *snap.Info) ([]string, error) {
// collect the directories, homes first
found, err := filepath.Glob(snap.DataHomeDir())
if err != nil {
return nil, err
}
// then system data
found = append(found, snap.DataDir())
return found, nil
}
func updateCurrentSymlinks(info *snap.Info) error {
mountDir := info.MountDir()
currentActiveSymlink := filepath.Join(mountDir, "..", "current")
if err := os.Remove(currentActiveSymlink); err != nil && !os.IsNotExist(err) {
logger.Noticef("Cannot remove %q: %v", currentActiveSymlink, err)
}
dataDir := info.DataDir()
currentDataSymlink := filepath.Join(dataDir, "..", "current")
if err := os.Remove(currentDataSymlink); err != nil && !os.IsNotExist(err) {
logger.Noticef("Cannot remove %q: %v", currentDataSymlink, err)
}
if err := os.MkdirAll(info.DataDir(), 0755); err != nil {
return err
}
if err := os.Symlink(filepath.Base(dataDir), currentDataSymlink); err != nil {
return err
}
return os.Symlink(filepath.Base(mountDir), currentActiveSymlink)
}