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Install OKD 3.11 (openshift) on oVirt

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Roy Golan edited this page Jan 6, 2019 · 17 revisions

DRAFT - WIP

Installing OKD on oVirt has many advantages, and its also got a lot easier these days. Admins and users who like to take container platform management for a spin, on oVirt, will be encouraged by this.

The installation uses the openshift-ansible and inside it specifically the openshift_ovirt ansible-role. The integration between openshift and oVirt is tighter, and provides storage integration. If you need persistent volumes for your containers you can get that directly from oVirt using the ovirt-volume-provisioner and** ovirt-flexvolume-driver**.

For the sake of simplicity, this installation will be an all-in-one Openshift cluster, on a single VM. On top of that we would run a classic web stack, Node.js + Postgres. Postgres will get a persistent volume from oVirt using its flexvolume driver.

Single shell file installation

Dropping to shell - this install.sh is a wrapper for installation of ovirt-openshift-installer container, it uses asible-playbook and has 2 main playbooks - 1 - install_okd.yaml and install_extensions.yaml. The latter is mainly for installing ovirt storage plugins.

The install.sh has one dependency, it needs to have 'podman' installed, all the rest runs inside a container. dnf install podman will do, for other ways to install podman consult the readme

Get the install.sh and customize

curl -O "https://raw.githubusercontent.com/oVirt/ovirt-openshift-extensions/master/automation/ci/{install.sh,customization.yaml}"

Edit the customization.yaml:

  • Put the engine details in engine_url

    engine_url: https://ovirt-engine-fqdn/ovirt-engine/api

  • Choose the oVirt cluster and data domain you want if you don't want 'Default'

    openshift_ovirt_cluster: yours
openshift_ovirt_data_store: yours

  • Unmark the memory check if you don't change the VM default memory for this install is 8Gb

    openshift_disable_check: memory_availability,disk_availability,docker_image_availability

  • Domain name of the setup. The setup will create a VM with the name master0.$public_hosted_zone here. It will be used for all the components of the setup

    public_hosted_zone: example.com

For a more complete list of customization please (refer to the vars.yaml](https://github.com/oVirt/ovirt-openshift-extensions/blob/master/automation/ci/vars.yaml) packed into the container.

Install

Run the install.sh to start the installation.

[user@bastion ~]# bash install.sh

What it would do is the following:

  1. Pull the ovirt-openshift-installer container and run it
  2. Download centos cloud image and import it into oVirt (set by qcow_url)
  3. Create a VM named master0.example.com based on the template above (domain name is set by public_hosted_zone)
  4. Cloud init will configure repositories, network, ovirt-guest-agent etc (set by cloud_init_script_master)
  5. The VM will dynamically be inserted into an ansible inventory, under master, compute, and etc groups
  6. Openshift-ansible main playbooks are executed - prerequisite.yml and deploy_cluster.yml to install OKD

In the end there is an all-in-one cluster running. Let's check it out.

[root@master0 ~]# oc get nodes
NAME                         STATUS    ROLES                  AGE       VERSION
master0.example.com   Ready     compute,infra,master   1h        v1.11.0+d4cacc0

Check oVirt's extensions

[root@master0 ~]# oc get deploy/ovirt-volume-provisioner
NAME                       DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
ovirt-volume-provisioner   1         1         1            1           57m

[root@master0 ~]# oc get ds/ovirt-flexvolume-driver
NAME                      DESIRED   CURRENT   READY     UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
ovirt-flexvolume-driver   1         1         1         1            1           <none>          59m

In case the router is not scheduled, label the node with this:

[root@master0 ~]# oc label node master0.example.com  "node-router=true"

To make all the dynamic storage provisioning run through ovirt's provisioner,
we need to set oVirt's storage class the default. Note a storage class defines which ovirt storage domain will
be used to provision the disks. Also it will set the disk type, thin/thick provision with thin the default.

[root@master ~]# oc patch sc/ovirt -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'

asciicast

Ready to go! Let's deploy mini messaging app written in java + postgresql with a persistent disk from ovirt.

Deploy persistent Postgres container with its storage from oVirt

A persistent deployment means that /var/lib/pgsql/data where the data is saved will be kept on a persistent volume disk. First let's pull a template of a persistent postgres deployment:

[root@master ~]# curl -O https://raw.githubusercontent.com/openshift/library/master/arch/x86_64/official/postgresql/templates/postgresql-persistent.json

Create a new-app based on this deployment. The parameters will create the proper persistent volume claim:

[root@master ~]# oc new-app postgresql-persistent.json \
  -e DATABASE_SERVICE_NAME=postgresql \
  -e POSTGRESQL_DATABASE=testdb \
  -e POSTGRESQL_PASSWORD=testdb \
  -e POSTGRESQL_USER=testdb \
  -e VOLUME_CAPACITY=10Gi \
  -e MEMORY_LIMIT=512M \
  -e POSTGRESQL_VERSION=10 \
  -e NAMESPACE=default \
  centos/postgresql-10-centos7

The disk is being created in oVirt for us, by the persistent storage claim:

[root@master0 ~]# oc get pvc/postgresql
NAME         STATUS    VOLUME                                     CAPACITY      ACCESS MODES   STORAGECLASS   AGE
postgresql   Bound     pvc-70a8ea75-0e03-11e9-8188-001a4a160100   10737418240   RWO            ovirt          5m

To demonstrate that oVirt created the disk, lets look for a disk with name as the VOLUME name of the claim:

[root@master0 ~]# curl -k  \
  -u admin@internal \
  'https://ovirt-engine-fqdn/ovirt-engine/api/disks?search=name=pvc-70a8ea75-0e03-11e9-8188-001a4a160100'  \
  | grep status
<status>ok</status>

Postgresql is ready with a persistent disk for its data!

Connect to the postgresql container:

[root@master0 ~]# oc rsh postgresql-10-centos7-1-89ldp

Query the testdb db:

sh-4.2$ psql testdb testdb -c "\l"
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges   
-----------+----------+----------+------------+------------+-----------------------
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 testdb    | testdb   | UTF8     | en_US.utf8 | en_US.utf8 | 
(4 rows)

### Deploy a demo message-logger application
I wrote a demo application in java on thorntail(former wildfly-swarm), that will persist messages to the db.
We will create the application from git sources:

```console
[root@master0 ~]# oc new-app https://github.com/

DRAFT

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