kolla-ansible/doc/source/reference/zun-guide.rst

Zun in Kolla

"Zun is an OpenStack Container service. It aims to provide an OpenStack API for provisioning and managing containerized workload on OpenStack." [1].

Preparation and Deployment

Zun requires kuryr and etcd services, for more information about how to configure kuryr refer to kuryr-guide.

To allow Zun Compute connect to the Docker Daemon, add the following in the docker.service file on each zun-compute node.

ExecStart= -H tcp://<DOCKER_SERVICE_IP>:2375 -H unix:///var/run/docker.sock --cluster-store=etcd://<DOCKER_SERVICE_IP>:2379 --cluster-advertise=<DOCKER_SERVICE_IP>:2375

Note

DOCKER_SERVICE_IP is zun-compute host IP address. 2375 is port that allows Docker daemon to be accessed remotely.

By default zun is disabled in the group_vars/all.yml. In order to enable it, you need to edit the file globals.yml and set the following variables:

enable_zun: "yes"
enable_kuryr: "yes"
enable_etcd: "yes"

Deploy the OpenStack cloud and zun.

$ kolla-ansible deploy

Verify

Generate the credentials file.

$ kolla-ansible post-deploy

Source credentials file.

$ . /etc/kolla/admin-openrc.sh

Download and create a glance container image.

$ docker pull cirros
$ docker save cirros | openstack image create cirros --public \
  --container-format docker --disk-format raw

Create zun container.

$ zun create --name test --net network=demo-net cirros ping -c4 8.8.8.8

Note

Kuryr does not support networks with DHCP enabled, disable DHCP in the subnet used for zun containers.

openstack subnet set --no-dhcp <subnet>

Verify container is created.

$ zun list
+--------------------------------------+------+---------------+---------+------------+------------+-------+
| uuid                                 | name | image         | status  | task_state | addresses  | ports |
+--------------------------------------+------+---------------+---------+------------+------------+-------+
| 3719a73e-5f86-47e1-bc5f-f4074fc749f2 | test | cirros        | Created | None       | 172.17.0.3 | []    |
+--------------------------------------+------+---------------+---------+------------+------------+-------+

Start container.

$ zun start test
Request to start container test has been accepted.

Verify container.

$ zun logs test
PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=45 time=96.396 ms
64 bytes from 8.8.8.8: seq=1 ttl=45 time=96.504 ms
64 bytes from 8.8.8.8: seq=2 ttl=45 time=96.721 ms
64 bytes from 8.8.8.8: seq=3 ttl=45 time=95.884 ms

--- 8.8.8.8 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 95.884/96.376/96.721 ms

For more information about how zun works, see zun, OpenStack Container service.