Quick admin guide

Introduction

After following this guide, users will have a working OpenNebula with a graphics interface (Sunstone), at least one hypervisor (host) and a running virtual machine. It is useful when setting up pilot clouds, for quickly testing new features and as a base deployment to build a large infrastructure.

There are two separate roles during the installation: the Frontend and Nodes. The Frontend server will run OpenNebula services, and Nodes will be used to implement virtual machines. Please do not follow this guide to create a single host combining the Frontend and Nodes on one server. However, it is recommended to create virtual machines on hosts with virtualization extensions. To test if your host supports virtualization extensions, please run:

# grep -E 'svm|vmx' /proc/cpuinfo

If you do not get any output, you probably do not have virtualization extensions supported/enabled on your server.

Package Layout
opennebula-server: OpenNebula Daemons
opennebula: OpenNebula CLI commands
opennebula-sunstone: OpenNebula’s web GUI
opennebula-java: OpenNebula Java API
opennebula-node-kvm: Install dependencies required by OpenNebula in the nodes
opennebula-gate: Send information from Virtual Machines to OpenNebula
opennebula-flow: Manage OpenNebula Services
opennebula-context: Package for OpenNebula Guests

Additionally opennebula-common and opennebula-ruby exist, but they are intended to be used as dependencies.

Warning

In order to avoid problems, you should disable SELinux in all nodes, the Frontend and Nodes.

# vi /etc/sysconfig/selinux
...
SELINUX=disabled
...
# setenforce 0
# getenforce
Permissive

Warning
Some commands may fail depending on your iptables/firewalls configuration. Disable the firewalls entirely for testing just to rule it out.

Frontend Installation

Note
Commands prefixed by # are meant to be run as root. Commands prefixed by $ must be run as oneadmin.

Install the repository

Enable the EPEL repository:

# yum install epel-release

Add the OpenNebula repository:

# cat << EOT > /etc/yum.repos.d/opennebula.repo

[opennebula]

SELINUX=disabled

name=opennebula

baseurl=http://downloads.opennebula.org/repo/4.12/CentOS/7/x86_64/

enabled=1

gpgcheck=0

EOT

Install the required packages

A complete installation of OpenNebula will have at least the opennebula-server and opennebula-sunstone packages:

# yum install opennebula-server opennebula-sunstone

You should run install_gems to install all the gem dependencies. Choose CentOS/RedHat if prompted:

# /usr/share/one/install_gems

lsb_release command not found. If you are using a RedHat based distribution install redhat-lsb

Select your distribution or press enter to continue without

installing dependencies.

1.Ubuntu/Debian

2.CentOS/RedHat

Configure and start the services

There are two main processes that must be started, i.e. the main OpenNebula daemon: oned, and the graphics user interface: sunstone.

Sunstone listens only to the loopback interface by default for security reasons. To change it, edit /etc/one/sunstone-server.conf and change :host: 127.0.0.1 to :host: 0.0.0.0.

Now we can start the services:

# systemctl enable opennebula

# systemctl start opennebula

# systemctl enable opennebula-sunstone

# systemctl start opennebula-sunstone

Configure NFS
Note

Skip this section if you are using a single server for both the frontend and worker node roles.

Export /var/lib/one/ from the frontend to the worker nodes. To do so, add the following to the /etc/exports file in the frontend:

/var/lib/one/ *(rw,sync,no_subtree_check,root_squash)

Refresh the NFS exports by doing:

# systemctl restart nfs.service

Configure the SSH Public Key

OpenNebula will need access to SSH passwordlessly from any node (including the frontend) to any other node.

Add the following snippet to ~/.ssh/config as oneadmin so it does not prompt to add keys to the known_hosts file:

# su - oneadmin

$ cat << EOT > ~/.ssh/config

Host *

StrictHostKeyChecking no

UserKnownHostsFile /dev/null

EOT

$ chmod 600 ~/.ssh/config

Nodes Installation

Install the repository

Add the OpenNebula repository:

# cat << EOT > /etc/yum.repos.d/opennebula.repo

[opennebula]

name=opennebula

baseurl=http://downloads.opennebula.org/repo/4.12/CentOS/7/x86_64/

enabled=1

gpgcheck=0

EOT

Install the required packages

# yum install opennebula-node-kvm

Start the required services:

# systemctl enable messagebus.service

# systemctl start messagebus.service

# systemctl enable libvirtd.service

# systemctl start libvirtd.service

# systemctl enable nfs.service

# systemctl start nfs.service

Configure the Network

Warning

Back up all the files that are modified in this section before making changes to them.

You will need to have your main interface connected to the bridge. We will do the following example with ens3, but the name of the interface may vary. An OpenNebula requirement is that the name of the bridge should be the same in all nodes.

To do so, substitute /etc/sysconfig/network-scripts/ifcfg-ens3 with:

DEVICE=ens3

BOOTPROTO=none

NM_CONTROLLED=no

ONBOOT=yes

TYPE=Ethernet

BRIDGE=br0

And add a new /etc/sysconfig/network-scripts/ifcfg-br0 file.

If you are using DHCP for your ens3 interface, use this template:

DEVICE=br0

TYPE=Bridge

ONBOOT=yes

BOOTPROTO=dhcp

NM_CONTROLLED=no

If you are using a static IP address, use another template:

DEVICE=br0

TYPE=Bridge

IPADDR=<YOUR_IPADDRESS>

NETMASK=<YOUR_NETMASK>

ONBOOT=yes

BOOTPROTO=static

NM_CONTROLLED=no

After these changes, restart the network:

# systemctl restart network.service

Configure NFS

Note

Skip this section if you are using a single server for both the frontend and worker node roles.

Mount the datastore export. Add the following to your /etc/fstab:

192.168.1.1:/var/lib/one/ /var/lib/one/ nfs soft,intr,rsize=8192,wsize=8192,noauto

Note

Replace 192.168.1.1 with the IP address of the frontend.

Mount the NFS share:

# mount /var/lib/one/

If the above command fails or hangs, it can be a firewall issue.

Basic Usage

Note

All the operations in this section can be performed using Sunstone instead of the command line. Point your browser to: http://frontend:9869.

The default password for the oneadmin user, which is randomly generated on every installation, can be found in ~/.one/one_auth.

Interact with OpenNebula from the oneadmin account in the frontend. We will assume that all the following commands are performed from this account. To login as oneadmin, run:

su – oneadmin

Adding a Host

To start running VMs, you should first register a worker node for OpenNebula.

Run this command for each node. Replace localhost with your node’s hostname.

$ onehost create localhost -i kvm -v kvm -n dummy

Run the onehost list command. If it fails, you probably have some problems with your ssh configuration. Look at /var/log/one/oned.log.

Adding virtual resources

Once it works, you need to create a network, an image and a virtual machine template.

To create a network, we need to create a network template file mynetwork.one that contains:

NAME = "private"

BRIDGE = br0

AR = [

TYPE = IP4,

IP = 192.168.0.100,

SIZE = 3

]

Note

Replace the address range with free IPs in your host network. You can add more than one address range.

Now we can move ahead and create resources in OpenNebula:

$ onevnet create mynetwork.one

$ oneimage create --name "CentOS-7-one-4.8" \

--path http://marketplace.c12g.com/appliance/53e7bf928fb81d6a69000002/download \

--driver qcow2 \

-d default

$ onetemplate create --name "CentOS-7" \

--cpu 1 --vcpu 1 --memory 512 --arch x86_64 \

--disk "CentOS-7-one-4.8" \

--nic "private" \

--vnc --ssh --net_context

Note

If the ‘oneimage create’ command complains because there is not enough space available in the datastore, you can disable the datastore capacity check in OpenNebula: /etc/one/oned.conf:DATASTORE_CAPACITY_CHECK = “no”. You need to restart OpenNebula after changing it.

You will need to wait until the image is ready to be used. Monitor its state by running oneimage list.

In order to dynamically add ssh keys to Virtual Machines we should add our ssh key to the user template by editing the user template:

$ EDITOR=vi oneuser update oneadmin

Add a new line like the following to the template:

SSH_PUBLIC_KEY="ssh-dss AAAAB3NzaC1kc3MAAACBANBWTQmm4Gt..."

Substitute the value above with the output of:

cat ~/.ssh/id_dsa.pub

Running a Virtual Machine

To run a Virtual Machine, you will need to instantiate a template:

$ onetemplate instantiate "CentOS-7"

Run onevm list and watch the virtual machine going from PENDING to PROLOG to RUNNING. If the VM fails, check the reason in the log: /var/log/one/<VM_ID>/vm.log.

Note

If it stays too long in the pend status, you can check why by doing: onevm show <vmid>|grep ^SCHED_MESSAGE. If it reports that no datastores have enough capacity for the VM, you can force a manual deployment by running: onevm deploy <vmid> <hostid>.