error for restore: lchown operation not permitted

[atomi]

Restore operation from a root user backup does execute and all files appear to be restored however this error occurs if you don't run the restore operation as a root user.

Output of restic version

[root@alarmpi ~]# restic version
restic 0.3.0 (v0.3.0-6-g6f72164)
compiled at 2016-10-05 09:06:15 with go1.7.1 on linux/arm

[atomi@workstation ~]# restic version
restic 0.3.0 (v0.3.0-19-g6b88d3b)
compiled at 2016-10-31 18:33:33 with go1.7.3 on linux/amd64

Expected behavior

restore should function without error stack trace

Actual behavior

[atomi@workstation ~]# restic -r test snapshots
ID        Date                 Host        Tags        Directory
----------------------------------------------------------------------
67d6c948  2016-11-01 15:33:13  alarmpi                 /root/backup

[atomi@workstation ~]# restic -r test restore 67d6c948 --target backup
restoring <Snapshot 67d6c948 of [/root/backup] at 2016-11-01 15:33:13.667132217 -0700 PDT by root@alarmpi> to backup
error for backup/backup: lchown backup/backup: operation not permitted
Lchown
restic.Node.restoreMetadata
        /tmp/restic-build-431614805/src/restic/node.go:147
restic.(*Node).CreateAt
        /tmp/restic-build-431614805/src/restic/node.go:134
restic.(*Restorer).restoreNodeTo
        /tmp/restic-build-431614805/src/restic/restorer.go:102
restic.(*Restorer).restoreTo
        /tmp/restic-build-431614805/src/restic/restorer.go:53
restic.(*Restorer).RestoreTo
        /tmp/restic-build-431614805/src/restic/restorer.go:122
main.runRestore
        /tmp/restic-build-431614805/src/cmds/restic/cmd_restore.go:135
main.glob..func13
        /tmp/restic-build-431614805/src/cmds/restic/cmd_restore.go:23
github.com/spf13/cobra.(*Command).execute
        /tmp/restic-build-431614805/src/github.com/spf13/cobra/command.go:599
github.com/spf13/cobra.(*Command).ExecuteC
        /tmp/restic-build-431614805/src/github.com/spf13/cobra/command.go:689
github.com/spf13/cobra.(*Command).Execute
        /tmp/restic-build-431614805/src/github.com/spf13/cobra/command.go:648
main.main
        /tmp/restic-build-431614805/src/cmds/restic/main.go:41
runtime.main
        /usr/local/go/src/runtime/proc.go:183
runtime.goexit
        /usr/local/go/src/runtime/asm_amd64.s:2086

Steps to reproduce the behavior

1. restic backup path using root user and owned by root
2. restore using non-root user

This may be related to #244

[fd0]

Thanks for reporting this. Are the files restored and restic only complains about the error, or did it stop there?

[atomi]

Are the files restored and restic only complains about the error

Yeah.

[fd0]

Thanks for the clarification, that's a user-interface issue then.

[middelink]

Partially. Nothing says we have to restore backups as root, right? Tar allows me to unpack a tar file where file are owned by someone other than myself and the world understand this behavior. Well, excluding Windows folks :P

How about this output (no stacktraces)

$ restic -r rest:http://qnap.**.********.**:8000 restore -t /tmp f5a13c51 -i /usr/sbin/e2label -i /usr/sbin/tune2fs 
restoring f5a13c51 to /tmp
error for /tmp/usr/sbin/e2label: Lchown: lchown /tmp/usr/sbin/e2label: operation not permitted
error for /tmp/usr/sbin/tune2fs: Lchown: lchown /tmp/usr/sbin/tune2fs: operation not permitted
There were 2 errors

[fd0]

Yes, that's what I have in mind, too. Warn the user that permissions could not be restored, but don't print a stacktrace and continue restoring.