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Chapter 4. Quick start example

This chapter provides an example to demonstrate the REST API’s ability to setup a basic Red Hat Virtualization environment and create a virtual machine. In addition to the standard prerequisites, this example requires the following:

  • A networked and configured Red Hat Virtualization installation;
  • An ISO file containing a desired virtual machine operating system to install. This chapter uses CentOS 7 for our installation ISO example; and
  • Red Hat Virtualization’s engine-iso-uploader tool to upload your chosen operating system ISO file.

This example uses curl to demonstrate API requests with a client application. Note that any application capable of HTTP requests can substitute for curl.

Important

For simplicity, the HTTP request headers in this example omit the Host and Authorization headers. However, these fields are mandatory and require data specific to your installation of Red Hat Virtualization.

Important

All the curl examples use admin@internal as the user name, mypassword as the password, /etc/pki/ovirt-engine/ca.pem as the certificate location and myengine.example.com as the host name. These are just examples, Make sure to replace them with valid values for your environment.

Note

Red Hat Virtualization generates an unique identifier for the id attribute for each resource. Identifier codes in this example might appear different to the identifier codes in your Red Hat Virtualization environment.

Note

In many examples of this section some of the attributes of results returned by the API have been omitted, to make them shorter. You can always use the reference to find the complete list of attributes. For example, if you want to see the complete list of attributes of the Cluster type, just go here.

4.1. Example: Access API entry point

The following request retrieves a representation of the main entry point for version 4 of of the API: 

GET /ovirt-engine/api HTTP/1.1
Version: 4
Accept: application/xml

Same request, but using the /v4 URL prefix instead of the Version header: 

GET /ovirt-engine/api/v4 HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
--user 'admin@internal:mypassword' \
https://myengine.example.com/ovirt-engine/api

The result will be an object of type Api: 

<api>
  <link href="/ovirt-engine/api/clusters" rel="clusters"/>
  <link href="/ovirt-engine/api/datacenters" rel="datacenters"/>
  ...
  <product_info>
    <name>oVirt Engine</name>
    <vendor>ovirt.org</vendor>
    <version>
      <build>0</build>
      <full_version>4.0.0-0.0.el7</full_version>
      <major>4</major>
      <minor>0</minor>
      <revision>0</revision>
    </version>
  </product_info>
  <special_objects>
    <blank_template href="..." id="..."/>
    <root_tag href="..." id="..."/>
  </special_objects>
  <summary>
    <hosts>
      <active>23</active>
      <total>30</total>
    </hosts>
    <storage_domains>
      <active>5</active>
      <total>6</total>
    </storage_domains>
    <users>
      <active>12</active>
      <total>102</total>
    </users>
    <vms>
      <active>253</active>
      <total>545</total>
    </vms>
  </summary>
  <time>2016-10-06T15:38:18.548+02:00</time>
</api>
Important

When neither the header nor the URL prefix are used, the server will automatically select a version. The default is version 4. You can change the default version using the ENGINE_API_DEFAULT_VERSION configuration parameter: 

# echo "ENGINE_API_DEFAULT_VERSION=3" > \
/etc/ovirt-engine/engine.conf.d/99-set-default-version.conf
# systemctl restart ovirt-engine

Changing this parameter affects all users of the API that don’t specify the version explicitly.

The entry point provides a user with links to the collections in a virtualization environment. The rel attribute of each collection link provides a reference point for each link. The next step in this example examines the data center collection, which is available through the datacenters link.

The entry point also contains other data such as product_info, special_objects and summary. This data is covered in chapters outside this example.

4.2. Example: List data centers

Red Hat Virtualization creates a Default data center on installation. This example uses the Default data center as the basis for our virtual environment.

The following request retrieves a representation of the data centers: 

GET /ovirt-engine/api/datacenters HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
--user 'admin@internal:mypassword' \
https://myengine.example.com/ovirt-engine/api/datacenters

The result will be a list of objects of type DataCenter: 

<data_centers>
  <data_center href="/ovirt-engine/api/datacenters/001" id="001">
    <name>Default</name>
    <description>The default Data Center</description>
    <link href="/ovirt-engine/api/datacenters/001/clusters" rel="clusters"/>
    <link href="/ovirt-engine/api/datacenters/001/storagedomains" rel="storagedomains"/>
    ...
    <local>false</local>
    <quota_mode>disabled</quota_mode>
    <status>up</status>
    <supported_versions>
      <version>
        <major>4</major>
        <minor>0</minor>
      </version>
    </supported_versions>
    <version>
      <major>4</major>
      <minor>0</minor>
    </version>
  </data_center>
  ...
</data_centers>

Note the id of your Default data center. It identifies this data center in relation to other resources of your virtual environment.

The data center also contains a link to the service that manages the storage domains attached to the data center: 

<link href="/ovirt-engine/api/datacenters/001/storagedomains" rel="storagedomains"/>

That service is used to attach storage domains from the main storagedomains collection, which this example covers later.

4.3. Example: List host clusters

Red Hat Virtualization creates a Default hosts cluster on installation. This example uses the Default cluster to group resources in your Red Hat Virtualization environment.

The following request retrieves a representation of the cluster collection: 

GET /ovirt-engine/api/clusters HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
--user 'admin@internal:mypassword' \
https://myengine.example.com/ovirt-engine/api/clusters

The result will be a list of objects of type Cluster: 

<clusters>
  <cluster href="/ovirt-engine/api/clusters/002" id="002">
    <name>Default</name>
    <description>The default server cluster</description>
    <link href="/ovirt-engine/api/clusters/002/networks" rel="networks"/>
    <link href="/ovirt-engine/api/clusters/002" rel="permissions"/>
    ...
    <cpu>
      <architecture>x86_64</architecture>
      <type>Intel Conroe Family</type>
    </cpu>
    <version>
      <major>4</major>
      <minor>0</minor>
    </version>
    <data_center href="/ovirt-engine/api/datacenters/001" id="001"/>
  </cluster>
  ...
</clusters>

Note the id of your Default host cluster. It identifies this host cluster in relation to other resources of your virtual environment.

The Default cluster is associated with the Default data center through a relationship using the id and href attributes of the data_center link: 

<data_center href="/ovirt-engine/api/datacenters/001" id="001"/>

The networks link is a reference to the service that manages the networks associated to this cluster. The next section examines the networks collection in more detail.

4.4. Example: List logical networks

Red Hat Virtualization creates a default ovirtmgmt network on installation. This network acts as the management network for Red Hat Virtualization Manager to access hosts.

This network is associated with our Default cluster and is a member of the Default data center. This example uses the ovirtmgmt network to connect our virtual machines.

The following request retrieves the list of logical networks: 

GET /ovirt-engine/api/networks HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
--user 'admin@internal:mypassword' \
https://myengine.example.com/ovirt-engine/api/networks

The result will be a list of objects of type Network: 

<networks>
  <network href="/ovirt-engine/api/networks/003" id="003">
    <name>ovirtmgmt</name>
    <description>Management Network</description>
    <link href="/ovirt-engine/api/networks/003/permissions" rel="permissions"/>
    <link href="/ovirt-engine/api/networks/003/vnicprofiles" rel="vnicprofiles"/>
    <link href="/ovirt-engine/api/networks/003/networklabels" rel="networklabels"/>
    <mtu>0</mtu>
    <stp>false</stp>
    <usages>
      <usage>vm</usage>
    </usages>
    <data_center href="/ovirt-engine/api/datacenters/001" id="001"/>
  </network>
  ...
</networks>

The ovirtmgmt network is attached to the Default data center through a relationship using the data center’s id.

The ovirtmgmt network is also attached to the Default cluster through a relationship in the cluster’s network sub-collection.

4.5. Example: List hosts

This example retrieves the list of hosts and shows a host named myhost registered with the virtualization environment: 

GET /ovirt-engine/api/hosts HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
--user 'admin@internal:mypassword' \
https://myengine.example.com/ovirt-engine/api/hosts

The result will be a list of objects of type Host: 

<hosts>
  <host href="/ovirt-engine/api/hosts/004" id="004">
    <name>myhost</name>
    <link href="/ovirt-engine/api/hosts/004/nics" rel="nics"/>
    ...
    <address>node40.example.com</address>
    <cpu>
      <name>Intel Core Processor (Haswell, no TSX)</name>
      <speed>3600</speed>
      <topology>
        <cores>1</cores>
        <sockets>2</sockets>
        <threads>1</threads>
      </topology>
    </cpu>
    <memory>8371830784</memory>
    <os>
      <type>RHEL</type>
      <version>
        <full_version>7 - 2.1511.el7.centos.2.10</full_version>
        <major>7</major>
      </version>
    </os>
    <port>54321</port>
    <status>up</status>
    <cluster href="/ovirt-engine/api/clusters/002" id="002"/>
  </host>
  ...
</hosts>

Note the id of your host. It identifies this host in relation to other resources of your virtual environment.

This host is a member of the Default cluster and accessing the nics sub-collection shows this host has a connection to the ovirtmgmt network.

4.6. Example: Create NFS data storage

An NFS data storage domain is an exported NFS share attached to a data center and provides storage for virtualized guest images. Creation of a new storage domain requires a POST request, with the storage domain representation included, sent to the URL of the storage domain collection.

You can enable the wipe after delete option by default on the storage domain. To configure this specify wipe_after_delete in the POST request. This option can be edited after the domain is created, but doing so will not change the wipe after delete property of disks that already exist.

The request should be like this: 

POST /ovirt-engine/api/storagedomains HTTP/1.1
Accept: application/xml
Content-type: application/xml

And the request body should be like this: 

<storage_domain>
  <name>mydata</name>
  <type>data</type>
  <description>My data</description>
  <storage>
    <type>nfs</type>
    <address>mynfs.example.com</address>
    <path>/exports/mydata</path>
  </storage>
  <host>
    <name>myhost</name>
  </host>
</storage_domain>

The same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<storage_domain>
  <name>mydata</name>
  <description>My data</description>
  <type>data</type>
  <storage>
    <type>nfs</type>
    <address>mynfs.example.com</address>
    <path>/exports/mydata</path>
  </storage>
  <host>
    <name>myhost</name>
  </host>
</storage_domain>
' \
https://myengine.example.com/ovirt-engine/api/storagedomains

The server uses host myhost to create a NFS data storage domain called mydata with an export path of mynfs.example.com:/exports/mydata. The API also returns the following representation of the newly created storage domain resource (of type StorageDomain): 

<storage_domain href="/ovirt-engine/api/storagedomains/005" id="005">
  <name>mydata</name>
  <description>My data</description>
  <available>42949672960</available>
  <committed>0</committed>
  <master>false</master>
  <status>unattached</status>
  <storage>
    <address>mynfs.example.com</address>
    <path>/exports/mydata</path>
    <type>nfs</type>
  </storage>
  <storage_format>v3</storage_format>
  <type>data</type>
  <used>9663676416</used>
</storage_domain>

4.7. Example: Create NFS ISO storage

An NFS ISO storage domain is a mounted NFS share attached to a data center and provides storage for DVD/CD-ROM ISO and virtual floppy disk (VFD) image files. Creation of a new storage domain requires a POST request, with the storage domain representation included, sent to the URL of the storage domain collection:

The request should be like this: 

POST /ovirt-engine/api/storagedomains HTTP/1.1
Accept: application/xml
Content-type: application/xml

And the request body should be like this: 

<storage_domain>
  <name>myisos</name>
  <description>My ISOs</description>
  <type>iso</type>
  <storage>
    <type>nfs</type>
    <address>mynfs.example.com</address>
    <path>/exports/myisos</path>
  </storage>
  <host>
    <name>myhost</name>
  </host>
</storage_domain>

The same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<storage_domain>
  <name>myisos</name>
  <description>My ISOs</description>
  <type>iso</type>
  <storage>
    <type>nfs</type>
    <address>mynfs.example.com</address>
    <path>/exports/myisos</path>
  </storage>
  <host>
    <name>myhost</name>
  </host>
</storage_domain>
' \
https://myengine.example.com/ovirt-engine/api/storagedomains

The server uses host myhost to create a NFS ISO storage domain called myisos with an export path of mynfs.example.com:/exports/myisos. The API also returns the following representation of the newly created storage domain resource (of type StorageDomain): 

<storage_domain href="/ovirt-engine/api/storagedomains/006" id="006">
  <name>myiso</name>
  <description>My ISOs</description>
  <available>42949672960</available>
  <committed>0</committed>
  <master>false</master>
  <status>unattached</status>
  <storage>
    <address>mynfs.example.com</address>
    <path>/exports/myisos</path>
    <type>nfs</type>
  </storage>
  <storage_format>v1</storage_format>
  <type>iso</type>
  <used>9663676416</used>
</storage_domain>

4.8. Example: Attach storage domains to data center

The following example attaches the mydata and myisos storage domains to the Default data center.

To attach the mydata storage domain, send a request like this: 

POST /ovirt-engine/api/datacenters/001/storagedomains HTTP/1.1
Accept: application/xml
Content-type: application/xml

With a request body like this: 

<storage_domain>
  <name>mydata</name>
</storage_domain>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<storage_domain>
  <name>mydata</name>
</storage_domain>
' \
https://myengine.example.com/ovirt-engine/api/datacenters/001/storagedomains

To attach the myisos storage domain, send a request like this: 

POST /ovirt-engine/api/datacenters/001/storagedomains HTTP/1.1
Accept: application/xml
Content-type: application/xml

With a request body like this: 

<storage_domain>
  <name>myisos</name>
</storage_domain>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<storage_domain>
  <name>myisos</name>
</storage_domain>
' \
https://myengine.example.com/ovirt-engine/api/datacenters/001/storagedomains

4.9. Example: Create virtual machine

The following example creates a virtual machine called myvm on the Default cluster using the virtualization environment’s Blank template as a basis. The request also defines the virtual machine’s memory as 512 MiB and sets the boot device to a virtual hard disk.

The request should be contain an object of type Vm describing the virtual machine to create: 

POST /ovirt-engine/api/vms HTTP/1.1
Accept: application/xml
Content-type: application/xml

And the request body should be like this: 

<vm>
  <name>myvm</name>
  <description>My VM</description>
  <cluster>
    <name>Default</name>
  </cluster>
  <template>
    <name>Blank</name>
  </template>
  <memory>536870912</memory>
  <os>
    <boot>
      <devices>
        <device>hd</device>
      </devices>
    </boot>
  </os>
</vm>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<vm>
  <name>myvm</name>
  <description>My VM</description>
  <cluster>
    <name>Default</name>
  </cluster>
  <template>
    <name>Blank</name>
  </template>
  <memory>536870912</memory>
  <os>
    <boot>
      <devices>
        <device>hd</device>
      </devices>
    </boot>
  </os>
</vm>
' \
https://myengine.example.com/ovirt-engine/api/vms

The response body will be an object of the Vm type: 

<vm href="/ovirt-engine/api/vms/007" id="007">
  <name>myvm</name>
  <link href="/ovirt-engine/api/vms/007/diskattachments" rel="diskattachments"/>
  <link href="/ovirt-engine/api/vms/007/nics" rel="nics"/>
  ...
  <cpu>
    <architecture>x86_64</architecture>
    <topology>
      <cores>1</cores>
      <sockets>1</sockets>
      <threads>1</threads>
    </topology>
  </cpu>
  <memory>1073741824</memory>
  <os>
    <boot>
      <devices>
        <device>hd</device>
      </devices>
    </boot>
    <type>other</type>
  </os>
  <type>desktop</type>
  <cluster href="/ovirt-engine/api/clusters/002" id="002"/>
  <status>down</status>
  <original_template href="/ovirt-engine/api/templates/000" id="00"/>
  <template href="/ovirt-engine/api/templates/000" id="000"/>
</vm>

4.10. Example: Create a virtual machine NIC

The following example creates a virtual network interface to connect the example virtual machine to the ovirtmgmt network.

The request should be like this: 

POST /ovirt-engine/api/vms/007/nics HTTP/1.1
Content-Type: application/xml
Accept: application/xml

The request body should contain an object of type Nic describing the NIC to be created: 

<nic>
  <name>mynic</name>
  <description>My network interface card</description>
</nic>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<nic>
  <name>mynic</name>
  <description>My network interface card</description>
</nic>
' \
https://myengine.example.com/ovirt-engine/api/vms/007/nics

4.11. Example: Create virtual machine disk

The following example creates an 8 GiB copy-on-write disk for the example virtual machine.

The request should be like this: 

POST /ovirt-engine/api/vms/007/diskattachments HTTP/1.1
Content-Type: application/xml
Accept: application/xml

The request body should be an object of type DiskAttachment describing the disk and how it will be attached to the virtual machine: 

<disk_attachment>
  <bootable>false</bootable>
  <interface>virtio</interface>
  <active>true</active>
  <disk>
    <description>My disk</description>
    <format>cow</format>
    <name>mydisk</name>
    <provisioned_size>8589934592</provisioned_size>
    <storage_domains>
      <storage_domain>
        <name>mydata</name>
      </storage_domain>
    </storage_domains>
  </disk>
</disk_attachment>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<disk_attachment>
  <bootable>false</bootable>
  <interface>virtio</interface>
  <active>true</active>
  <disk>
    <description>My disk</description>
    <format>cow</format>
    <name>mydisk</name>
    <provisioned_size>8589934592</provisioned_size>
    <storage_domains>
      <storage_domain>
        <name>mydata</name>
      </storage_domain>
    </storage_domains>
  </disk>
</disk_attachment>
' \
https://myengine.example.com/ovirt-engine/api/vms/007/diskattachments

The storage_domains attribute tells the API to store the disk on the mydata storage domain.

4.12. Example: Attach ISO image to virtual machine

The boot media for our example virtual machine requires an CD-ROM or DVD ISO image for an operating system installation. This example uses a CentOS 7 image for installation.

ISO images must be available in the myisos ISO domain for the virtual machines to use. Red Hat Virtualization provides an uploader tool that ensures that the ISO images are uploaded into the correct directory path with the correct user permissions.

Once the ISO is uploaded, an API can be used to request the list of files from the ISO storage domain: 

GET /ovirt-engine/api/storagedomains/006/files HTTP/1.1
Accept: application/xml

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request GET \
--header 'Version: 4' \
--header 'Accept: application/xml' \
https://myengine.example.com/ovirt-engine/api/storagedomains/006/files

The server returns the following list of objects of type File, one for each available ISO (or floppy) image: 

<files>
  <file href="..." id="CentOS-7-x86_64-Minimal.iso">
    <name>CentOS-7-x86_64-Minimal.iso</name>
  </file>
  ...
</files>

An API user attaches the CentOS-7-x86_64-Minimal.iso to our example virtual machine. Attaching an ISO image is equivalent to using the Change CD button in the administration or user portal applications.

The request should be like this: 

PUT /ovirt-engine/api/vms/007/cdroms/00000000-0000-0000-0000-000000000000 HTTP/1.1
Accept: application/xml
Content-type: application/xml

The request body should be an object of type Cdrom containing an inner file attribute to indicate the identifier of the ISO (or floppy) image: 

<cdrom>
  <file id="CentOS-7-x86_64-Minimal.iso"/>
</cdrom>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request PUT \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<cdrom>
  <file id="CentOS-7-x86_64-Minimal.iso"/>
</cdrom>
' \
https://myengine.example.com/ovirt-engine/api/vms/007/cdroms/00000000-0000-0000-0000-000000000000

For more details see the documentation of the service that manages virtual machine CD-ROMS.

4.13. Example: Start the virtual machine

The virtual environment is complete and the virtual machine contains all necessary components to function. This example starts the virtual machine using the start method.

The request should be like this: 

POST /ovirt-engine/api/vms/007/start HTTP/1.1
Accept: application/xml
Content-type: application/xml

The request body should be like this: 

<action>
  <vm>
    <os>
      <boot>
        <devices>
          <device>cdrom</device>
        </devices>
      </boot>
    </os>
  </vm>
</action>

Same request, using the curl command: 

# curl \
--cacert '/etc/pki/ovirt-engine/ca.pem' \
--user 'admin@internal:mypassword' \
--request POST \
--header 'Version: 4' \
--header 'Content-Type: application/xml' \
--header 'Accept: application/xml' \
--data '
<action>
  <vm>
    <os>
      <boot>
        <devices>
          <device>cdrom</device>
        </devices>
      </boot>
    </os>
  </vm>
</action>
' \
https://myengine.example.com/ovirt-engine/api/vms/007/start

The additional request body sets the virtual machine’s boot device to CD-ROM for this boot only. This enables the virtual machine to install the operating system from the attached ISO image. The boot device reverts back to disk for all future boots.

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