The rkt (pronounced “rocket”) container manager is just too easy to run on CentOS7!
Here’s me running a Docker Ubuntu 16.04.1 LTS image on CentOS7 (Dell 1950 III with 8 GB RAM) for the first time in under a minute. Ubuntu actually starts in 3 seconds once downloaded.
Download the rkt RPM then …
# rpm -Uvh rkt-1.18.0-1.x86_64.rpm # cat /etc/redhat-release CentOS Linux release 7.2.1511 (Core) # uptime 06:16:04 up 141 days, 51 min, 1 user, load average: 0.18, 0.26, 0.22 # rkt run --interactive docker://ubuntu --insecure-options=image Downloading sha256:6bbedd9b76a [=============================] 49.9 MB / 49.9 MB Downloading sha256:fc19d60a83f [=============================] 824 B / 824 B Downloading sha256:668604fde02 [=============================] 160 B / 160 B Downloading sha256:de413bb911f [=============================] 444 B / 444 B Downloading sha256:2879a7ad314 [=============================] 678 B / 678 B root@rkt-2ee79be0-a70b-44be-90fd-1a1a54c17216:/# cat /etc/os-release NAME="Ubuntu" VERSION="16.04.1 LTS (Xenial Xerus)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 16.04.1 LTS" VERSION_ID="16.04" HOME_URL="http://www.ubuntu.com/" SUPPORT_URL="http://help.ubuntu.com/" BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/" UBUNTU_CODENAME=xenial root@rkt-2ee79be0-a70b-44be-90fd-1a1a54c17216:/# uptime 06:16:27 up 141 days, 52 min, 0 users, load average: 0.25, 0.27, 0.22 root@rkt-2ee79be0-a70b-44be-90fd-1a1a54c17216:/# ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 06:16 ? 00:00:00 /usr/lib/systemd/systemd --default-standard-output=tty --log-target=null --show-status=0 root 3 1 0 06:16 ? 00:00:00 /usr/lib/systemd/systemd-journald root 5 1 0 06:16 console 00:00:00 /bin/bash root 13 5 0 06:16 console 00:00:00 ps -ef root@rkt-2ee79be0-a70b-44be-90fd-1a1a54c17216:/# exit # cat /etc/redhat-release CentOS Linux release 7.2.1511 (Core) # uptime 06:16:58 up 141 days, 52 min, 1 user, load average: 0.15, 0.24, 0.22
Is 0.0% memory usage light-weight enough? 
# ps aux | egrep -e "[U]SER|[r]kt" USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 6711 0.4 0.0 41772 2244 pts/0 S+ 07:22 0:01 stage1/rootfs/usr/lib/ld-linux-x86-64.so.2 stage1/rootfs/usr/bin/systemd-nspawn --boot --notify-ready=yes --register=true --link-journal=try-guest --quiet --uuid=40660e8b-09c0-46c2-893e-53de6d4068ff --machine=rkt-40660e8b-09c0-46c2-893e-53de6d4068ff --directory=stage1/rootfs --capability=CAP_AUDIT_WRITE,CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FSETID,CAP_FOWNER,CAP_KILL,CAP_MKNOD,CAP_NET_RAW,CAP_NET_BIND_SERVICE,CAP_SETUID,CAP_SETGID,CAP_SETPCAP,CAP_SETFCAP,CAP_SYS_CHROOT -- --default-standard-output=tty --log-target=null --show-status=0
rkt prepare
Get Started with rkt Containers in Three Minutes