userns-remap: auto-created WORKDIR has wrong owner

[AlekseyMartynov]

Output of docker version:

Client:
 Version:      1.10.2
 API version:  1.22
 Go version:   go1.5.3
 Git commit:   c3959b1
 Built:        Mon Feb 22 21:37:01 2016
 OS/Arch:      linux/amd64

Server:
 Version:      1.10.2
 API version:  1.22
 Go version:   go1.5.3
 Git commit:   c3959b1
 Built:        Mon Feb 22 21:37:01 2016
 OS/Arch:      linux/amd64

Output of docker info:

Containers: 1
 Running: 0
 Paused: 0
 Stopped: 1
Images: 7
Server Version: 1.10.2
Storage Driver: aufs
 Root Dir: /var/lib/docker/100000.100000/aufs
 Backing Filesystem: extfs
 Dirs: 16
 Dirperm1 Supported: false
Execution Driver: native-0.2
Logging Driver: json-file
Plugins:
 Volume: local
 Network: bridge null host
Kernel Version: 3.13.0-24-generic
Operating System: Ubuntu 14.04.2 LTS
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 994.1 MiB
Name: cs26257
ID: HOND:5EEV:AWFN:KGS4:52JB:5S6R:G2XO:7V5T:AU7W:46IG:34DE:N66I
WARNING: No swap limit support

Dockerfile:

FROM node
WORKDIR /dir123
RUN npm install lodash

Build fails with:

npm ERR! Error: EACCES: permission denied, access '/dir123'
npm ERR!     at Error (native)
npm ERR!  { [Error: EACCES: permission denied, access '/dir123'] errno: -13, code: 'EACCES', syscall: 'access', path: '/dir123' }

Indeed, owner of WORKDIR is real root

/var/lib/docker/100000.100000/aufs/diff/a343b6854cf13ecbbd370e9678db2dd4dce5eaa60631a732b6443d1b34f4f094

ls -l

total 12
drwxr-xr-x 2 root   root   4096 Mar  5 21:42 dir123
drwx------ 3 100000 100000 4096 Mar  5 21:42 root
drwxrwxrwt 3 100000 100000 4096 Mar  5 21:42 tmp

[thaJeztah]

Looks a bit similar to this one #20446

ping @estesp 😄