Installing docker.io on centos 6.4 (64-bit)
Installing docker.io on centos 6.4 (64-bit)
UPDATE-1: Docker version-0.6.1 is released. Upgrade instructions are available here
UPDATE-2: Docker version-0.6.2 is released.
Docker.io is the lightweight "container engine + image repository" built on top of LXC (linux lightweight containers) to ship any application.
At the core of docker.io there are
- an application "/usr/bin/docker"
- set of pre-created operating-system/application images hosted with "docker.io"
- AUFS (Another Union filesystem) to take care of snapshots, diffs, ro/rw requirements
- LXC (Linux lightweight containers)
- cgroups (for resource management and namespacing)
Follow these instructions to get docker.io installed on your system.
0. Install centos 6.x
1. Disable selinux as it interferes with functionality of LXC
[root@localhost ~]# cat /etc/selinux/config # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - SELinux is fully disabled. SELINUX=disabled # SELINUXTYPE= type of policy in use. Possible values are: # targeted - Only targeted network daemons are protected. # strict - Full SELinux protection. SELINUXTYPE=targeted2. Download and setup Fedora EPEL Repository
sudo yum install http://ftp.riken.jp/Linux/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
3. Setup hop5.in repository
cd /etc/yum.repos.d sudo wget http://www.hop5.in/yum/el6/hop5.repo
4. Install docker-io package
[root@localhost ~]# yum install docker-io Loaded plugins: fastestmirror, security Loading mirror speeds from cached hostfile * base: centos.excellmedia.net * epel: kartolo.sby.datautama.net.id * extras: centos.excellmedia.net * updates: centos.excellmedia.net Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package docker-io.x86_64 0:0.5.3-4.el6 will be installed --> Processing Dependency: lxc >= 0.8.0 for package: docker-io-0.5.3-4.el6.x86_64 --> Processing Dependency: kernel-ml-aufs >= 3.10.5 for package: docker-io-0.5.3-4.el6.x86_64 --> Running transaction check ---> Package kernel-ml-aufs.x86_64 0:3.10.5-3.el6 will be installed ---> Package lxc.x86_64 0:0.8.0-3.el6 will be installed --> Processing Dependency: liblxc.so.0()(64bit) for package: lxc-0.8.0-3.el6.x86_64 --> Running transaction check ---> Package lxc-libs.x86_64 0:0.8.0-3.el6 will be installed --> Finished Dependency Resolution Dependencies Resolved ============================================================================================ Package Arch Version Repository Size ============================================================================================ Installing: docker-io x86_64 0.5.3-4.el6 hop5 1.2 M Installing for dependencies: kernel-ml-aufs x86_64 3.10.5-3.el6 hop5 33 M lxc x86_64 0.8.0-3.el6 hop5 81 k lxc-libs x86_64 0.8.0-3.el6 hop5 75 k Transaction Summary ============================================================================================ Install 4 Package(s) Total download size: 34 M Installed size: 159 M Is this ok [y/N]: y Downloading Packages: (1/4): docker-io-0.5.3-4.el6.x86_64.rpm | 1.2 MB 00:03 (2/4): kernel-ml-aufs-3.10.5-3.el6.x86_64.rpm | 33 MB 00:33 (3/4): lxc-0.8.0-3.el6.x86_64.rpm | 81 kB 00:00 (4/4): lxc-libs-0.8.0-3.el6.x86_64.rpm | 75 kB 00:00 -------------------------------------------------------------------------------------------- Total 896 kB/s | 34 MB 00:39 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : lxc-libs-0.8.0-3.el6.x86_64 1/4 Installing : lxc-0.8.0-3.el6.x86_64 2/4 Installing : kernel-ml-aufs-3.10.5-3.el6.x86_64 3/4 Installing : docker-io-0.5.3-4.el6.x86_64 4/4 Verifying : kernel-ml-aufs-3.10.5-3.el6.x86_64 1/4 Verifying : lxc-0.8.0-3.el6.x86_64 2/4 Verifying : lxc-libs-0.8.0-3.el6.x86_64 3/4 Verifying : docker-io-0.5.3-4.el6.x86_64 4/4 Installed: docker-io.x86_64 0:0.5.3-4.el6 Dependency Installed: kernel-ml-aufs.x86_64 0:3.10.5-3.el6 lxc.x86_64 0:0.8.0-3.el6 lxc-libs.x86_64 0:0.8.0-3.el6 Complete! [root@localhost ~]#
5. See the package is installed correctly
[root@localhost ~]# docker -h Usage of docker: -D=false: Debug mode -H=[unix:///var/run/docker.sock]: tcp://host:port to bind/connect to or unix://path/to/socket to use -api-enable-cors=false: Enable CORS requests in the remote api. -b="": Attach containers to a pre-existing network bridge. Use 'none' to disable container networking -d=false: Daemon mode -dns="": Set custom dns servers -g="/var/lib/docker": Path to graph storage base dir. -p="/var/run/docker.pid": File containing process PID -r=false: Restart previously running containers
6. Add cgroup filesystem to /etc/fstab , so that docker will work correctly
[root@localhost ~]# echo "none /sys/fs/cgroup cgroup defaults 0 0" >> /etc/fstab
[root@localhost ~]# mount /sys/fs/cgroup
Per "Peter Zimmerman" a reboot is needed to actually mount /sys/fs/cgroup (due to the kernel doesn't have cgroup support). So, the above mount step is not really needed. As its used only upon reboot.
7. Reboot the system ; make sure to select "3.10.5-3.el6.x86_64" kernel version while booting.
8. Once system is up and running, make sure you are on right kernel
[root@localhost ~]# uname -r 3.10.5-3.el6.x86_64 [root@localhost ~]# grep aufs /proc/filesystems nodev aufs9. Start the docker.io in daemon mode (in a different terminal)
[root@localhost ~]# docker -d 2013/08/21 07:47:07 WARNING: Your kernel does not support cgroup swap limit. 2013/08/21 07:47:07 Listening for HTTP on /var/run/docker.sock (unix)
10. Print hello world from a centos 6.4 container.
[root@localhost ~]# docker run centos:6.4 echo "hello world" 2013/08/21 07:48:41 POST /v1.4/containers/create 2013/08/21 07:48:41 POST /v1.4/containers/c6bc9e80097e/start 2013/08/21 07:48:41 POST /v1.4/containers/c6bc9e80097e/attach?logs=1&stderr=1&stdout=1&stream=1 hello world
11. Ping from inside the container
[root@localhost ~]# docker -dns '8.8.8.8' run centos:6.4 ping -c 3 yahoo.com 2013/08/21 08:02:15 POST /v1.4/containers/create 2013/08/21 08:02:15 POST /v1.4/containers/c40a1244f9bc/start 2013/08/21 08:02:15 POST /v1.4/containers/c40a1244f9bc/attach?logs=1&stderr=1&stdout=1&stream=1 PING yahoo.com (98.138.253.109) 56(84) bytes of data. 64 bytes from ir1.fp.vip.ne1.yahoo.com (98.138.253.109): icmp_seq=1 ttl=48 time=323 ms 64 bytes from ir1.fp.vip.ne1.yahoo.com (98.138.253.109): icmp_seq=2 ttl=48 time=329 ms 64 bytes from ir1.fp.vip.ne1.yahoo.com (98.138.253.109): icmp_seq=3 ttl=49 time=302 ms --- yahoo.com ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2304ms rtt min/avg/max/mdev = 302.032/318.318/329.656/11.807 ms
TROUBLESHOOTING
[root@localhost ~]# docker -dns="8.8.8.8" run centos:6.4 yum install hiphop-php 2013/08/21 07:53:05 POST /v1.4/containers/create 2013/08/21 07:53:05 POST /v1.4/containers/6d9fef14bd1a/start 2013/08/21 07:53:05 POST /v1.4/containers/6d9fef14bd1a/attach?logs=1&stderr=1&stdout=1&stream=1 Loaded plugins: fastestmirror Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was 14: PYCURL ERROR 6 - "Couldn't resolve host 'mirrorlist.centos.org'"
pkill docker
iptables -t nat -F
ifconfig docker0 down
brctl delbr docker0
docker -d
pkill docker
iptables -t nat -F
ifconfig docker0 down
brctl delbr docker0
docker -d
It will force docker to recreate the bridge and reinit all the network rules
!/bin/bash
### BEGIN INIT INFO
# INIT INFO
# Provides: docker
# Required-Start: networking
# Required-Stop: networking
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: docker
# Description: docker
### END INIT INFO
. /etc/init.d/functions
NAME=docker
PID_FILE="/var/run/${NAME}.pid"
DELAY=0
status_q() {
status -p $PID_FILE $NAME > /dev/null
return $?
}
start_app() {
nohup /usr/bin/docker -d >/var/log/docker.log 2>&1 </dev/null &
return $?
}
start() {
status_q; res=$?
if [ $res -eq 3 ]; then
echo -n $"$NAME starting..."
start_app
echo $! > $PID_FILE
[ $DELAY -gt 0 ] && sleep $DELAY
status_q; res=$?
[ $res -eq 0 ] && success || failure
echo
elif [ $res -eq 0 ]; then
success; echo "$NAME is already running"
else
failure; echo "$NAME is not running, res: $res"
fi
return $res
}
stop() {
status_q; res=$?
if [ $res -eq 3 ]; then
success && echo "$NAME is not running"
else
killproc -p $PID_FILE; res=$?
if [ $res -eq 0 ]; then
rm -f PID_FILE
success && echo "$NAME has been stopped"
else
failure && echo "$NAME cannot be stopped ($res)"
fi
fi
return $res
}
case $1 in
start)
start
exit $?
;;
stop)
stop
exit $?
;;
status)
echo -n $"$NAME running..."
status_q; res=$?
[ $res -eq 0 ] && success || failure
echo
exit $res
;;
restart)
stop
start
exit $?
;;
*)
echo "Usage: $0 {start|stop|restart|status}"
exit 2
;;
esac