Difference between revisions of "Docker inside CT"
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== Container tuning == | == Container tuning == | ||
| − | * | + | * Create Fedora 20 container: |
vzctl create $veid --ostemplate fedora-20-x86_64 | vzctl create $veid --ostemplate fedora-20-x86_64 | ||
| − | * | + | * Turn on bridge feature to allow docker creating bridged network: |
vzctl set $veid --features bridge:on --save | vzctl set $veid --features bridge:on --save | ||
| − | * | + | * Setup Container veth-based network: |
vzctl set $veid --netif_add eth0 --save | vzctl set $veid --netif_add eth0 --save | ||
| − | * | + | * Allow all iptables modules being used in containers: |
vzctl set $veid --netfilter full --save | vzctl set $veid --netfilter full --save | ||
| − | * | + | * Configure custom cgroups in systemd: |
vzctl mount $veid | vzctl mount $veid | ||
echo "JoinControllers=cpu,cpuacct,cpuset,freezer,devices" >> /vz/root/$veid/etc/systemd/system.conf | echo "JoinControllers=cpu,cpuacct,cpuset,freezer,devices" >> /vz/root/$veid/etc/systemd/system.conf | ||
| − | * | + | * Start the container: |
vzctl start $veid | vzctl start $veid | ||
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These steps are to be performed inside the container. | These steps are to be performed inside the container. | ||
| − | * | + | * Install Docker: |
yum -y install docker-io | yum -y install docker-io | ||
| − | * | + | * Start docker daemon |
docker -d -s vfs | docker -d -s vfs | ||
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Use Docker to start Wordpress (official, standard way). | Use Docker to start Wordpress (official, standard way). | ||
| − | * | + | * Start mysql docker: |
docker run --name test-mysql -e MYSQL_ROOT_PASSWORD=123 -d mysql | docker run --name test-mysql -e MYSQL_ROOT_PASSWORD=123 -d mysql | ||
| − | * | + | * Start wordpress: |
docker run --name test-wordpress --link test-mysql:mysql -p 8080:80 -d wordpress | docker run --name test-wordpress --link test-mysql:mysql -p 8080:80 -d wordpress | ||
| − | * | + | * Access wordpress server by container IP and port 8080: <pre><nowiki>http://container_ip:8080</nowiki></pre> |
== Limitations == | == Limitations == | ||
Revision as of 22:42, 11 February 2015
Since OpenVZ kernel 042stab105.4 it is possible to run Docker inside containers. This article describes how.
Contents
Prerequisites
- Kernel 042stab105.4 or later version
- Kernel module veth module is loaded on host
Container tuning
- Create Fedora 20 container:
vzctl create $veid --ostemplate fedora-20-x86_64
- Turn on bridge feature to allow docker creating bridged network:
vzctl set $veid --features bridge:on --save
- Setup Container veth-based network:
vzctl set $veid --netif_add eth0 --save
- Allow all iptables modules being used in containers:
vzctl set $veid --netfilter full --save
- Configure custom cgroups in systemd:
vzctl mount $veid echo "JoinControllers=cpu,cpuacct,cpuset,freezer,devices" >> /vz/root/$veid/etc/systemd/system.conf
- Start the container:
vzctl start $veid
Prepare Docker in container
These steps are to be performed inside the container.
- Install Docker:
yum -y install docker-io
- Start docker daemon
docker -d -s vfs
Example usage
Wordpress
Use Docker to start Wordpress (official, standard way).
- Start mysql docker:
docker run --name test-mysql -e MYSQL_ROOT_PASSWORD=123 -d mysql
- Start wordpress:
docker run --name test-wordpress --link test-mysql:mysql -p 8080:80 -d wordpress
- Access wordpress server by container IP and port 8080:
http://container_ip:8080
Limitations
- This feature is currently in beta
- Only "vfs" Docker graph driver is currently supported
