arch_single_local

Single Front-end & Local Storage

In this scenario we will have a single front-end hosting all the OpenNebula services and a set of hosts that will act as hypervisors to run Virtual Machines (VM). Let’s us review some the main components.

Storage

Virtual disk images are stored in local storage, with the front-end hosting an image repository (image datastore). These images are subsequently transferred from the front-end to the hypervisors to initiate the virtual machines (VMs). Both the front-end and hypervisors utilize the directory /var/lib/one/datastores to store these images. It is possible to either utilize the root file system (FS) for this directory or symlink from any other location.

The following snippet shows the configuration required if no mount points are used:

ds:
  mode: ssh

⚠️ Note: If you want to use a dedicated volume for all your datastores, you can pre-mount it in /var/lib/one/datastores/.

If you want to use a dedicated volume mounted in a custom location (for example /mnt/one_datastores/), then you need to pre-create directories (owned by oneadmin) for each datastore and use the following snippet which will cause symlinks to be created automatically:

ds:

  mode: ssh
  mounts:
  - type: system
    path: /mnt/one_datastores/system/
  - type: image
    path: /mnt/one_datastores/default/
  - type: files
    path: /mnt/one_datastores/files/

The final setting on the hosts will be:

$ tree /mnt/one_datastores/
/mnt/one_datastores/
├── system
├── default
└── files

$ tree /var/lib/one/datastore/
/var/lib/one/datastores/
├── 0 -> /mnt/one_datastores/system/
├── 1 -> /mnt/one_datastores/default/
└── 2 -> /mnt/one_datastores/files/

Networking

The most basic network configuration is a flat network (bridged). We will use the main interface of the Host to connect the VMs to the Network. The interfaces used in this mode are depicted in the following picture:

⚠️ Note: The playbook requires either Netplan or NetworkManager to be present in the Hosts to perform the initial configuration.

To create the virtual network for the VMs you need to pick up some IP. These IP addresses need to be reachable through the Network used by the main interface of the host, as the VM traffic will be forwarded through it.

The following snippet shows how to define a virtual network using some IPs in the Admin Network (the one used by the hosts):

    vn:
      admin_net:
        managed: true
        template:
          VN_MAD: bridge
          PHYDEV: eth0
          BRIDGE: br0
          AR:
            TYPE: IP4
            IP: 10.0.0.50
            SIZE: 48
          NETWORK_ADDRESS: 10.0.0.0
          NETWORK_MASK: 255.255.255.0
          GATEWAY: 10.0.0.1
          DNS: 1.1.1.1

If there is any other interface in the hosts you can use them. For example to define a dedicated VM network using bon0 and vxlan networking:

      vms_net:
        managed: true
        template:
          VN_MAD: vxlan
          PHYDEV: bond0
          BRIDGE: br1
          VLAN_ID: 123
          FILTER_IP_SPOOFING: 'NO'
          FILTER_MAC_SPOOFING: 'YES'
          GUEST_MTU: 1450
          AR:
            TYPE: IP4
            IP: 192.168.0.10
            SIZE: 100
          NETWORK_ADDRESS: 192.168.0.0
          NETWORK_MASK: 255.255.255.0
          GATEWAY: 192.168.0.1
          DNS: 192.168.0.1

OpenNebula Front-end & Services

The Ansible playbook installs a complete suite of OpenNebula services including the base daemons (oned and scheduler), the OpenNebula Flow and Gate services and Sunstone Web-UI. You can just need to select the OpenNebula version to install and a pick a password for oneadmin

one_pass: opennebula
one_version: '6.6'

Enterprise Edition

You can use your enterprise distribution with the Ansible playbooks. Simply add your token to the var file. Also you can enable the Prometheus and Grafana integration part of the Enterprise Edition:

one_token: example:example
features:
  prometheus: true

The complete inventory file

The following file show the complete settings to install a single front-end with two hosts using local storage:

---
all:
  vars:
    ansible_user: root
    one_version: '6.6'
    one_pass: opennebulapass
    vn:
      admin_net:
        managed: true
        template:
          VN_MAD: bridge
          PHYDEV: eth0
          BRIDGE: br0
          AR:
            TYPE: IP4
            IP: 172.20.0.100
            SIZE: 48
          NETWORK_ADDRESS: 172.20.0.0
          NETWORK_MASK: 255.255.255.0
          GATEWAY: 172.20.0.1
          DNS: 1.1.1.1

frontend:
  hosts:
    fe1: { ansible_host: 172.20.0.7 }

node:
  hosts:
    node1: { ansible_host: 172.20.0.8 }
    node2: { ansible_host: 172.20.0.9 }

Running the Ansible Playbook

• 1. Prepare the inventory file: Update the local.yml file in the inventory file to match your infrastructure settings. Please be sure to update or review the following variables:

  • ansible_user, update it if different from root.
  • one_pass, change it to the password for the oneadmin account
  • one_version, be sure to use the latest stable version here

• 2. Check the connection: Verify the network connection, ssh and sudo configuration run the following command:

ansible -i inventory/local.yml all -m ping -b

• 3. Site installation: Now we can run the site playbook that install and configure OpenNebula services

ansible-playbook -i inventory/local.yml opennebula.deploy.main

Once the execution of the playbook finish your new OpenNebula cloud is ready. You can now head to the verification guide.