I joined the selinux list and sent the above, but I have not seen it posted. I rebuilt my test system with stock centos 7.4 with the docker that it comes with and the kernel that it comes with. It runs fine before enabling userns-remap: [root@localhost ~]# uname -r 3.10.0-693.17.1.el7.x86_64 [root@localhost ~]# cat /etc/redhat-release CentOS Linux release 7.4.1708 (Core) [root@localhost ~]# docker --version Docker version 1.12.6, build 3e8e77d/1.12.6 [root@localhost ~]# grep 3.10.0-693.17.1.el7.x86_64 /boot/grub2/grub.cfg menuentry 'CentOS Linux (3.10.0-693.17.1.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-693.11.6.el7.x86_64-advanced-3ac2b526-6c37-46f7-8539-67bc4e55dd49' { linux16 /vmlinuz-3.10.0-693.17.1.el7.x86_64 root=/dev/mapper/VolGroup00-LogVol00 ro no_timer_check console=tty0 console=ttyS0,115200n8 net.ifnames=0 biosdevname=0 crashkernel=auto rd.lvm.lv=VolGroup00/LogVol00 rd.lvm.lv=VolGroup00/LogVol01 rhgb quiet LANG=en_US.UTF-8 user_namespace.enable=1 namespace.unpriv_enable=1 initrd16 /initramfs-3.10.0-693.17.1.el7.x86_64.img [root@localhost ~]# docker run hello-world | head -n2 Hello from Docker! Then when I add userns-remap it fails: [root@localhost ~]# cat /etc/docker/daemon.json { "userns-remap": "default" } [root@localhost ~]# systemctl restart docker [root@localhost ~]# docker run hello-world nsenter: unable to unshare namespaces: Invalid argument container_linux.go:247: starting container process caused "process_linux.go:245: running exec setns process for init caused \"exit status 1\"" /usr/bin/docker-current: Error response from daemon: invalid header field value "oci runtime error: container_linux.go:247: starting container process caused \"process_linux.go:245: running exec setns process for init caused \\\"exit status 1\\\"\"\n". This symptom is reported here: https://bugzilla.redhat.com/show_bug.cgi?id=1441993 CLOSED INSUFFICIENT_DATA Mr. Walsh commented in that: Daniel Walsh 2017-04-13 09:15:06 EDT "Why would usernamespace be required for this? You might want to try user namespace with docker-latest, but as of now we don't support user namespace on RHEL." But that was obviously several months ago. Also similar here: https://github.com/moby/moby/issues/25929 But that suggests adding: user_namespace.enable=1 which I've done already: [root@localhost ~]# grep user_namespace.enable /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-693.17.1.el7.x86_64 root=/dev/mapper/VolGroup00-LogVol00 ro no_timer_check console=tty0 console=ttyS0,115200n8 net.ifnames=0 biosdevname=0 crashkernel=auto rd.lvm.lv=VolGroup00/LogVol00 rd.lvm.lv=VolGroup00/LogVol01 rhgb quiet LANG=en_US.UTF-8 user_namespace.enable=1 namespace.unpriv_enable=1 I feel like this problem must be solved, but it doesn't appear solved with the "stock" system. Thoughts?