REST API Guide

Red Hat Virtualization 4.4

Using the Red Hat Virtualization REST Application Programming Interface

Red Hat Virtualization Documentation Team

Abstract

This guide describes the Red Hat Virtualization Manager Representational State Transfer Application Programming Interface.
This guide is generated from documentation comments in the ovirt-engine-api-model code, and is currently partially complete. Updated versions of this documentation will be published as new content becomes available.

Chapter 1. Introduction

The Red Hat Virtualization Manager provides a Representational State Transfer (REST) API. The API provides software developers and system administrators with control over their Red Hat Virtualization environment outside of the standard web interface. The API is useful for developers and administrators to integrate the functionality of a Red Hat Virtualization environment with custom scripts or external applications that access the API via the standard Hypertext Transfer Protocol (HTTP).

The benefits of the API are:

  • Broad client support - Any programming language, framework, or system with support for HTTP protocol can use the API.
  • Self descriptive - Client applications require minimal knowledge of the virtualization infrastructure, as many details are discovered at runtime.
  • Resource-based model - The resource-based REST model provides a natural way to manage a virtualization platform.

This provides developers and administrators with the ability to:

  • Integrate with enterprise IT systems.
  • Integrate with third-party virtualization software.
  • Perform automated maintenance or error-checking tasks.
  • Automate repetitive tasks in a Red Hat Virtualization environment with scripts.

This documentation acts as a reference for the Red Hat Virtualization API. It aims to provide developers and administrators with instructions and examples to help harness the functionality of their Red Hat Virtualization environment through the API, either directly or using the provided SDKs.

1.1. Representational State Transfer

Representational State Transfer (REST) is a design architecture that focuses on resources for a specific service and their representations. A resource representation is a key abstraction of information that corresponds to one specific managed element on a server. A client sends a request to a server element located at a Uniform Resource Identifier (URI) and performs operations with standard HTTP methods, such as GET, POST, PUT, and DELETE. This provides a stateless communication between the client and server where each request acts independently of any other request, and contains all the information necessary to complete the request.

1.2. API Prerequisites

Prerequisites for using the Red Hat Virtualization API:

  • A networked installation of Red Hat Virtualization Manager, which includes the API.
  • A client or programming library that initiates and receives HTTP requests from the API server. For example:

  • Knowledge of Hypertext Transfer Protocol (HTTP), the protocol used for REST API interactions. The Internet Engineering Task Force provides a Request for Comments (RFC) explaining the Hypertext Transfer Protocol at http://www.ietf.org/rfc/rfc2616.txt.
  • Knowledge of Extensible Markup Language (XML) or JavaScript Object Notation (JSON), which the API uses to construct resource representations. The W3C provides a full specification on XML at http://www.w3.org/TR/xml. ECMA International provide a free publication on JSON at http://www.ecma-international.org.

Chapter 2. Authentication and Security

2.1. TLS/SSL Certification

The Red Hat Virtualization API requires Hypertext Transfer Protocol Secure (HTTPS) [1] for secure interaction with client software, such as the SDK and CLI components. This involves obtaining the CA certificate used by the server, and importing it into the certificate store of your client.

2.1.1. Obtaining the CA Certificate

You can obtain the CA certificate from the Red Hat Virtualization Manager and transfer it to the client machine using one of these methods:

Method 1

The preferred method for obtaining the CA certificate is to use the openssl s_client command line tool to perform a real TLS handshake with the server, and then extract the certificates that it presents. Run a command like this:

$ openssl s_client \
-connect myengine.example.com:443 \
-showcerts \
< /dev/null

This command will connect to the server and display output similar to the following:

CONNECTED(00000003)
depth=1 C = US, O = Example Inc., CN = myengine.example.com.23416
verify error:num=19:self signed certificate in certificate chain
---
Certificate chain
 0 s:/C=US/O=Example Inc./CN=myengine.example.com
   i:/C=US/O=Example Inc./CN=myengine.example.com.23416
-----BEGIN CERTIFICATE-----
MIIEaTCCA1GgAwIBAgICEAQwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx
FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs
SVlJe7e5FTEtHJGTAeWWM6dGbsFhip5VXM0gfqg=
-----END CERTIFICATE-----
 1 s:/C=US/O=Example Inc./CN=myengine.example.com.23416
   i:/C=US/O=Example Inc./CN=myengine.example.com.23416
-----BEGIN CERTIFICATE-----
MIIDxjCCAq6gAwIBAgICEAAwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx
FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs
Pkyg1rQHR6ebGQ==
-----END CERTIFICATE-----

The text between the -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- marks shows the certificates presented by the server. The first one is the certificate of the server itself, and the last one is the certificate of the CA. Copy the CA certificate, including the marks, to the ca.crt file. The result should look like this:

-----BEGIN CERTIFICATE-----
MIIDxjCCAq6gAwIBAgICEAAwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx
FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs
Pkyg1rQHR6ebGQ==
-----END CERTIFICATE-----
Important

This is the most reliable method to obtain the CA certificate used by the server. The rest of the methods described here will work in most cases, but they will not obtain the correct CA certificate if it has been manually replaced by the administrator of the server.

Method 2

If you cannot use the openssl s_client method described above, you can instead use a command line tool to download the CA certificate from the Red Hat Virtualization Manager.

Examples of command line tools include curl and wget, both of which are available on multiple platforms.

If using curl:

$ curl \
--output ca.crt \
'http://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA'

If using wget:

$ wget \
--output-document ca.crt \
'http://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA'
Method 3

Use a web browser to navigate to the certificate located at:

https://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA

Depending on the chosen browser, the certificate either downloads or imports into the browser’s keystore.

  1. If the browser downloads the certificate: save the file as ca.crt.
  2. If the browser imports the certificate: export it from the browser’s certification options and save it as ca.crt.
Method 4

Log in to the Red Hat Virtualization Manager, export the certificate from the truststore, and copy it to your client machine.

  1. Log in to the Red Hat Virtualization Manager machine as root.
  2. Export the certificate from the truststore using the Java keytool management utility:

    # keytool \
    -keystore /etc/pki/ovirt-engine/.truststore \
    -storepass mypass \
    -exportcert \
    -alias cacert \
    -rfc \
    -file ca.crt

    This creates a certificate file called ca.crt.

  3. Copy the certificate to the client machine using the scp command:

    $ scp ca.crt myuser@myclient.example.com:/home/myuser/.

Each of these methods results in a certificate file named ca.crt on your client machine. You must then import this file into the certificate store of the client.

2.1.2. Importing a Certificate to a Client

Importing a certificate to a client relies on how the client stores and interprets certificates. See your client documentation for more information on importing a certificate.

2.2. Authentication

Any user with a Red Hat Virtualization Manager account has access to the API. All requests must be authenticated using either OAuth or basic authentication, as described below.

2.2.1. OAuth Authentication

Since version 4.0 of Red Hat Virtualization the preferred authentication mechanism is OAuth 2.0, as described in RFC 6749.

OAuth is a sophisticated protocol, with several mechanisms for obtaining authorization and access tokens. For use with the Red Hat Virtualization API, the only supported one is the Resource Owner Password Credentials Grant, as described in section 4.3 of RFC 6749.

You must first obtain a token, sending the user name and password to the Red Hat Virtualization Manager single sign-on service:

POST /ovirt-engine/sso/oauth/token HTTP/1.1
Host: myengine.example.com
Content-Type: application/x-www-form-urlencoded
Accept: application/json

The request body must contain the grant_type, scope, username, and password parameters:

Table 2.1. OAuth token request parameters

NameValue

grant_type

password

scope

ovirt-app-api

username

admin@internal

password

mypassword

These parameters must be URL-encoded. For example, the @ character in the user name needs to be encoded as %40. The resulting request body will be something like this:

grant_type=password&scope=ovirt-app-api&username=admin%40internal&password=mypassword
Important

The scope parameter is described as optional in the OAuth RFC, but when using it with the Red Hat Virtualization API it is mandatory, and its value must be ovirt-app-api.

If the user name and password are valid, the Red Hat Virtualization Manager single sign-on service will respond with a JSON document similar to this one:

{
  "access_token": "fqbR1ftzh8wBCviLxJcYuV5oSDI=",
  "token_type": "bearer",
  "scope": "...",
  ...
}

For API authentication purposes, the only relevant name/value pair is the access_token. Do not manipulate this in any way; use it exactly as provided by the SSO service.

Once the token has been obtained, it can be used to perform requests to the API by including it in the HTTP Authorization header, and using the Bearer scheme. For example, to get the list of virtual machines, send a request like this:

GET /ovirt-engine/api/vms HTTP/1.1
Host: myengine.example.com
Accept: application/xml
Authorization: Bearer fqbR1ftzh8wBCviLxJcYuV5oSDI=

The token can be used multiple times, for multiple requests, but it will eventually expire. When it expires, the server will reject the request with the 401 HTTP response code:

HTTP/1.1 401 Unauthorized

When this happens, a new token is needed, as the Red Hat Virtualization Manager single sign-on service does not currently support refreshing tokens. A new token can be requested using the same method described above.

2.2.2. Basic Authentication

Important

Basic authentication is supported only for backwards compatibility; it is deprecated since version 4.0 of Red Hat Virtualization, and will be removed in the future.

Each request uses HTTP Basic Authentication [2] to encode the credentials. If a request does not include an appropriate Authorization header, the server sends a 401 Authorization Required response:

HEAD /ovirt-engine/api HTTP/1.1
Host: myengine.example.com

HTTP/1.1 401 Authorization Required

Request are issued with an Authorization header for the specified realm. Encode an appropriate Red Hat Virtualization Manager domain and user in the supplied credentials with the username@domain:password convention.

The following table shows the process for encoding credentials in Base64.

Table 2.2. Encoding credentials for API access

ItemValue

User name

admin

Domain

internal

Password

mypassword

Unencoded credentials

admin@internal:mypassword

Base64 encoded credentials

YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA==

Provide the Base64-encoded credentials as shown:

HEAD /ovirt-engine/api HTTP/1.1
Host: myengine.example.com
Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA==

HTTP/1.1 200 OK
Important

Basic authentication involves potentially sensitive information, such as passwords, sent as plain text. The API requires Hypertext Transfer Protocol Secure (HTTPS) for transport-level encryption of plain-text requests.

Important

Some Base64 libraries break the result into multiple lines and terminate each line with a newline character. This breaks the header and causes a faulty request. The Authorization header requires the encoded credentials on a single line within the header.

2.2.3. Authentication Sessions

The API also provides authentication session support. Send an initial request with authentication details, then send all subsequent requests using a session cookie to authenticate.

2.2.3.1. Requesting an Authenticated Session

  1. Send a request with the Authorization and Prefer: persistent-auth headers:

    HEAD /ovirt-engine/api HTTP/1.1
    Host: myengine.example.com
    Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA==
    Prefer: persistent-auth
    
    HTTP/1.1 200 OK
    ...

    This returns a response with the following header:

    Set-Cookie: JSESSIONID=5dQja5ubr4yvI2MM2z+LZxrK; Path=/ovirt-engine/api; Secure

    Take note of the JSESSIONID= value. In this example the value is 5dQja5ubr4yvI2MM2z+LZxrK.

  2. Send all subsequent requests with the Prefer: persistent-auth and Cookie headers with the JSESSIONID= value. The Authorization header is no longer needed when using an authenticated session.

    HEAD /ovirt-engine/api HTTP/1.1
    Host: myengine.example.com
    Prefer: persistent-auth
    Cookie: JSESSIONID=5dQja5ubr4yvI2MM2z+LZxrK
    
    HTTP/1.1 200 OK
    ...
  3. When the session is no longer required, perform a request to the sever without the Prefer: persistent-auth header.

    HEAD /ovirt-engine/api HTTP/1.1
    Host: myengine.example.com
    Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA==
    
    HTTP/1.1 200 OK
    ...


[1] HTTPS is described in RFC 2818 HTTP Over TLS.

Chapter 3. Common concepts

3.1. Types

The API uses the type concept to describe the different kinds of objects accepted and returned.

There are three relevant kinds of types:

Primitive types
Describe simple kinds of objects, like strings or integers.
Enumerated types
Describe lists of valid values like VmStatus or DiskFormat.
Structured types
Describe structured objects, with multiple attributes and links, like Vm or Disk.

3.2. Identified types

Many of the types used by the API represent identified objects, objects that have an unique identifier and exist independently of other objects. The types used to describe those objects extend the Identified type, which contains the following set of common attributes:

AttributeTypeDescription

id

String

Each object in the virtualization infrastructure contains an id, which acts as an unique identifier.

href

String

The canonical location of the object as an absolute path.

name

String

A user-supplied human readable name for the object. The name name is unique across all objects of the same type.

description

String

A free-form user-supplied human readable description of the object.

Important

Currently for most types of objects the id attribute is actually a randomly generated UUID, but this is an implementation detail, and users should not rely on that, as it may change in the future. Instead users should assume that these identifiers are just strings.

3.3. Objects

Objects are the individual instances of the types supported by the API. For example, the virtual machine with identifier 123 is an object of the Vm type.

3.4. Collections

A collection is a set of objects of the same type.

3.5. Representations

The state of objects needs to be represented when it is transferred beetween the client and the server. The API supports XML and JSON as the representation of the state of objects, both for input and output.

3.5.1. XML representation

The XML representation of an object consists of an XML element corresponding to the type of the object, XML attributes for the id and href attributes, and nested XML elements for the rest of the attributes. For example, the XML representation for a virtual machine appears as follows:

<vm id="123" href="/ovirt-engine/api/vms/123">
  <name>myvm</name>
  <description>My VM</description>
  <memory>1073741824</memory>
  ...
</vm>

The XML representation of a collection of objects consists of an XML element, named after the type of the objects, in plural. This contains the representations of the objects of the collection. For example, the XML respresentation for a collection of virtual machines appears as follows:

<vms>
  <vm id="123" href="/ovirt-engine/api/vms/123">
    <name>yourvm</name>
    <description>Your VM</description>
    <memory>1073741824</memory>
    ...
  </vm>
  <vm id="456" href="/ovirt-engine/api/vms/456">
    <name>myname</name>
    <description>My description</description>
    <memory>2147483648</memory>
    ...
  </vm>
  ...
</vms>
Important

In the XML representation of objects the id and href attributes are the only ones that are represented as XML attributes, the rest are represented as nested XML elements.

3.5.2. JSON representation

The JSON representation of an object consists of a JSON document containing a name/value pair for each attribute (including id and href). For example, the JSON representation of a virtual machine appears as follows:

{
  "id": "123",
  "href": "/ovirt-engine/api/vms/123",
  "name": "myvm",
  "description": "My VM",
  "memory": 1073741824,
  ...
}

The JSON representation of a collection of objects consists of a JSON document containg a name/value pair (named ater the type of the objects, in singular) which in turn contains an array with the representations of the objects of the collection. For example, the JSON respresentation for a collection of virtual machines appears as follows:

{
  "vm": [
    {
      "id": "123",
      "href": "/ovirt-engine/api/vms/123",
      "name": "myvm",
      "description": "My VM",
      "memory": 1073741824,
      ...
    },
    {
      "id": "456",
      "href": "/ovirt-engine/api/vms/456",
      "name": "yourvm",
      "description": "Your VM",
      "memory": 2147483648,
      ...
    },
  ]
}

3.6. Services

Services are the parts of the server responsible for retrieving, adding updating, removing and executing actions on the objects supported by the API.

There are two relevant kinds of services:

Services that manage a collection of objects
These services are reponsible for listing existing objects and adding new objects. For example, the Vms service is responsible for managing the collection of virtual machines available in the system.
Services that manage a specific object
These services are responsible for retrieving, updating, deleting and executing actions in specific objects. For example, the Vm service is responsible for managing a specific virtual machine.

Each service is accessible via a particular path within the server. For example, the service that manages the collection of virtual machines available in the system is available in the via the path /vms, and the service that manages the virtual machine 123 is available via the path /vms/123.

All kinds of services have a set of methods that represent the operations that they can perform. The services that manage collections of objects usually have the list and add methods. The services that manage specific objects usually have the get, update and remove methods. In addition, services may also have action methods, that represent less common operations. For example, the Vm service has a start method that is used to start a virtual machine.

For the more usual methods there is a direct mapping between the name of the method and the name of the HTTP method:

Method nameHTTP method

add

POST

get

GET

list

GET

update

PUT

remove

DELETE

The path used in the HTTP request is the path of the service, with the /ovirt-engine/api prefix.

For example, the request to list the virtual machines should be like this, using the HTTP GET method and the path /vms:

GET /ovirt-engine/api/vms

For action methods the HTTP method is always POST, and the name of the method is added as a suffix to the path. For example, the request to start virtual machine 123 should look like this, using the HTTP POST method and the path /vms/123/start:

POST /ovirt-engine/api/vms/123/start

Each method has a set of parameters.

Parameters are classified into two categories:

Main parameter
The main parameter corresponds the object or collection that is retrieved, added or updated. This only applies to the add, get, list and update methods, and there will be exactly one such main parameter per method.
Secondary parameters
The rest of the parameters.

For example, the operation that adds a virtual machine (see here) has three parameters: vm, clone and clone_permissions. The main parameter is vm, as it describes the object that is added. The clone and clone_permissions parameters are secondary parameters.

The main parameter, when used for input, must be included in the body of the HTTP request. For example, when adding a virtual machine, the vm parameter, of type Vm, must be included in the request body. So the complete request to add a virtual machine, including all the HTTP details, must look like this:

POST /ovirt-engine/api/vms HTTP/1.1
Host: myengine.example.com
Authorization: Bearer fqbR1ftzh8wBCviLxJcYuV5oSDI=
Content-Type: application/xml
Accept: application/xml

<vm>
  <name>myvm</name>
  <description>My VM</description>
  <cluster>
    <name>Default</name>
  </cluster>
  <template>
    <name>Blank</name>
  </template>
</vm>

When used for output, the main parameters are included in the response body. For example, when adding a virtual machine, the vm parameter will be included in the response body. So the complete response body will look like this:

HTTP/1.1 201 Created
Content-Type: application/xml

<vm href="/ovirt-engine/api/vms/123" id="123">
  <name>myvm</name>
  <description>My VM</description>
  ...
</vm>

Secondary parameters are only allowed for input (except for action methods, which are described later), and they must be included as query parameters. For example, when adding a virtual machine with the clone parameter set to true, the complete request must look like this:

POST /ovirt-engine/api/vms?clone=true HTTP/1.1
Host: myengine.example.com
Authorization: Bearer fqbR1ftzh8wBCviLxJcYuV5oSDI=
Content-Type: application/xml
Accept: application/xml

<vm>
  <name>myvm</name>
  <description>My VM</description>
  <cluster>
    <name>Default</name>
  </cluster>
  <template>
    <name>Blank</name>
  </template>
</vm>

Action methods only have secondary parameters. They can be used for input and output, and they should be included in the request body, wrapped with an action element. For example, the action method used to start a virtual machine (see here) has a vm parameter to describe how the virtual machine should be started, and a use_cloud_init parameter to specify if cloud-init should be used to configure the guest operating system. So the complete request to start virtual machine 123 using cloud-init will look like this when using XML:

POST /ovirt-engine/api/vms/123/start HTTP/1.1
Host: myengine.example.com
Authorization: Bearer fqbR1ftzh8wBCviLxJcYuV5oSDI=
Content-Type: application/xml
Accept: application/xml

<action>
  <use_cloud_init>true</use_cloud_init>
  <vm>
    <initialization>
      <nic_configurations>
        <nic_configuration>
          <name>eth0</name>
          <on_boot>true</on_boot>
          <boot_protocol>static</boot_protocol>
          <ip>
            <address>192.168.0.100</address>
            <netmask>255.255.255.0</netmask>
            <gateway>192.168.0.1</netmask>
          </ip>
        </nic_configuration>
      </nic_configurations>
      <dns_servers>192.168.0.1</dns_servers>
    </initialization>
  </vm>
</action>

3.7. Searching

The list method of some services has a search parameter that can be used to specify search criteria. When used, the server will only return objects within the collection that satisfy those criteria. For example, the following request will return only the virtual machine named myvm:

GET /ovirt-engine/api/vms?search=name%3Dmyvm

3.7.1. Maximum results parameter

Use the max parameter to limit the number of objects returned. For example, the following request will only return one virtual machine, regardless of how many are available in the system:

GET /ovirt-engine/api/vms?max=1

A search request without the max parameter will return all the objects. Specifying the max parameter is recommended to reduce the impact of requests in the overall performance of the system.

3.7.2. Case sensitivity

By default queries are not case sensitive. For example, the following request will return the virtual machines named myvm, MyVM and MYVM:

GET /ovirt-engine/api/vms?search=name%3Dmyvm

The optional case_sensitive boolean parameter can be used to change this behaviour. For example, to get exactly the virtual machine named myhost, and not MyHost or MYHOST, send a request like this:

GET /ovirt-engine/api/vms?search=name%3D=myvm&case_sensitive=true

3.7.3. Search syntax

The search parameters use the same syntax as the Red Hat Virtualization query language:

(criteria) [sortby (element) asc|desc]

The sortby clause is optional and only needed when ordering results.

Example search queries:

CollectionCriteriaResult

hosts

vms.status=up

Returns a list of all hosts running virtual machines that are up.

vms

domain=example.com

Returns a list of all virtual machines running on the specified domain.

vms

users.name=mary

Returns a list of all virtual machines belonging to users with the user name mary.

events

severity > normal sortby time

Returns a list of all events with severity higher than normal and sorted by the the value of their time attribute.

events

severity > normal sortby time desc

Returns a list of all events with severity higher than normal and sorted by the the value of their time attribute in descending order.

The value of the search parameter must be URL-encoded to translate reserved characters, such as operators and spaces. For example, the equal sign should be encoded as %3D:

GET /ovirt-engine/api/vms?search=name%3Dmyvm

3.7.4. Wildcards

The asterisk can be used as part of a value, to indicate that any string matches, including the emtpy string. For example, the following request will return all the virtual machines with names beginning with myvm, such as myvm, myvm2, myvma or myvm-webserver:

GET /ovirt-engine/api/vms?search=name%3Dmyvm*

3.7.5. Pagination

Some Red Hat Virtualization environments contain large collections of objects. Retrieving all of them with one request isn’t practical, and hurts performace. To allow retrieving them page by page the search parameter supports an optional page clause. This, combined with the max parameter, is the basis for paging. For example, to get the first page of virtual machines, with a page size of 10 virtual machines, send request like this:

GET /ovirt-engine/api/vms?search=page%201&max=10
Note

The search parameter is URL-encoded, the actual value of the search parameter, before encoding, is page 1, so this is actually requesting the first page.

Increase the page value to retrieve the next page:

GET /ovirt-engine/api/vms?search=page%202&max=10

The page clause can be used in conjunction with other clauses inside the search parameter. For example, the following request will return the second page of virtual machines, but sorting by name:

GET /ovirt-engine/api/vms?search=sortby%20name%20page%202&max=10
Important

The API is stateless; it is not possible to retain a state between different requests since all requests are independent from each other. As a result, if a status change occurs between your requests, then the page results may be inconsistent.

For example, if you request a specific page from a list of virtual machines, and virtual machines are created or removed before you request the next page, then your results may be missing some of them, or contain duplicates.

3.8. Following links

The API returns references to related objects as links. For example, when a virtual machine is retrieved it contains links to its disk attachments and network interface cards:

<vm id="123" href="/ovirt-engine/api/vms/123">
  ...
  <link rel="diskattachments" href="/ovirt-engine/api/vms/123/diskattachments"/>
  <link rel="nics" href="/ovirt-engine/api/vms/123/nics"/>
  ...
</vm>

The complete description of those linked objects can be retrieved by sending separate requests:

GET /ovirt-engine/api/vms/123/diskattachments
GET /ovirt-engine/api/vms/123/nics

However, in some situations it is more convenient for the application using the API to retrieve the linked information in the same request. This is useful, for example, when the additional network round trips introduce an unacceptable overhead, or when the multiple requests complicate the code of the application in an unacceptable way. For those use cases the API provides a follow parameter that allows the application to retrieve the linked information using only one request.

The value of the follow parameter is a list of strings, separated by commas. Each of those strings is the path of the linked object. For example, to retrieve the disk attachments and the NICs in the example above the request should be like this:

GET /ovirt-engine/api/vms/123?follow=disk_attachments,nics

That will return an response like this:

<vm id="123" href="/ovirt-engine/api/vms/123">
  ...
  <disk_attachments>
    <disk_attachment id="456" href="/ovirt-engine/api/vms/123/diskattachments/456">
      <active>true</active>
      <bootable>true</bootable>
      <interface>virtio_scsi</interface>
      <pass_discard>false</pass_discard>
      <read_only>false</read_only>
      <uses_scsi_reservation>false</uses_scsi_reservation>
      <disk id="789" href="/ovirt-engine/api/disks/789"/>
    </disk_attachment>
    ...
  </disk_attacments>
  <nics>
    <nic id="234" href="/ovirt-engine/api/vms/123/nics/234">
      <name>eth0</name>
      <interface>virtio</interface>
      <linked>true</linked>
      <mac>
        <address>00:1a:4a:16:01:00</address>
      </mac>
      <plugged>true</plugged>
    </nic>
    ...
  </nics>
  ...
</vm>

The path to the linked object can be a single word, as in the previous example, or it can be a sequence of words, separated by dots, to request nested data. For example, the previous example used disk_attachments in order to retrieve the complete description of the disk attachments, but each disk attachment contains a link to the disk, which wasn’t followed. In order to also follow the links to the disks, the following request can be used:

GET /ovirt-engine/api/vms/123?follow=disk_attachments.disk

That will result in the following response:

<vm id="123" href="/ovirt-engine/api/vms/123">
  <disk_attachments>
    <disk_attachment id="456" href="/ovirt-engine/api/vms/123/diskattachments/456">
      <active>true</active>
      <bootable>true</bootable>
      <interface>virtio_scsi</interface>
      <pass_discard>false</pass_discard>
      <read_only>false</read_only>
      <uses_scsi_reservation>false</uses_scsi_reservation>
      <disk id="789" href="/ovirt-engine/api/disks/789">
        <name>mydisk</name>
        <description>My disk</description>
        <actual_size>0</actual_size>
        <format>raw</format>
        <sparse>true</sparse>
        <status>ok</status>
        <storage_type>image</storage_type>
        <total_size>0</total_size>
        ...
      </disk>
    </disk_attachment>
    ...
  </disk_attachments>
  ...
</vm>

The path can be made as deep as needed. For example, to also get the statistics of the disks:

GET /ovirt-engine/api/vms/123?follow=disk_attachments.disk.statistics

Multiple path elements and multiple paths can be combined. For example, to get the disk attachments and the network interface cards, both with their statistics:

GET /ovirt-engine/api/vms/123?follow=disk_attachments.disk.statistics,nics.statistics
Important

Almost all the operations that retrieve objects support the follow parameter, but make sure to explicitly check the reference documentation, as some operations may not support it, or may provide advice on how to use it to get the best performance.

Important

Using the follow parameter moves the overhead from the client side to the server side. When you request additional data, the server must fetch and merge it with the basic data. That consumes CPU and memory in the server side, and will in most cases require additional database queries. That may adversely affect the performance of the server, especially in large scale environments. Make sure to test your application in a realistic environment, and use the follow parameter only when justified.

3.9. Permissions

Many of the services that manage a single object provide a reference to a permissions service that manages the permissions assigned to that object. Each permission contains links to the user or group, the role and the object. For example, the permissions assigned to a specific virtual machine can be retrieved sending a request like this:

GET /ovirt-engine/api/vms/123/permissions

The response body will look like this:

<permissions>
  <permission id="456" href="/ovirt-engien/api/vms/123/permissions/456">
    <user id="789" href="/ovirt-engine/api/users/789"/>
    <role id="abc" href="/ovirt-engine/api/roles/abc"/>
    <vm id="123" href="/ovirt-engine/api/vms/123"/>
  </permission>
  ...
</permissions>

A permission is added to an object sending a POST request with a permission representation to this service. Each new permission requires a role and a user.

3.10. Handling errors

Some errors require further explanation beyond a standard HTTP status code. For example, the API reports an unsuccessful object state update or action with a fault in the response body. The fault contains the reason and detail attributes. For example, when the server receives a request to create a virtual machine without the mandatory name attribute it will respond with the following HTTP response line:

HTTP/1.1 400 Bad Request

And the following response body:

<fault>
  <reason>Incomplete parameters</reason>
  <detail>Vm [name] required for add</detail>
</fault>

Chapter 4. Quick Start Examples

The examples in this section show you how to use the REST API to set up a basic Red Hat Virtualization environment and to create a virtual machine. In addition to the standard prerequisites, these examples require the following:

  • A networked and configured Red Hat Virtualization installation.
  • An ISO file containing the virtual machine operating system you want to install. This chapter uses CentOS 7 for the installation ISO example.

The API examples use curl to demonstrate API requests with a client application. You can use any application that sends HTTP requests.

Important

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.

The curl examples use admin@internal for the user name, mypassword for the password, /etc/pki/ovirt-engine/ca.pem for the certificate location, and myengine.example.com for the host name. You must replace them with the correct values for your environment.

Red Hat Virtualization generates a unique identifier for the id attribute for each resource. Identifier codes in this example will differ from the identifier codes in your Red Hat Virtualization environment.

In many examples, some attributes of the results returned by the API have been omitted, for brevity. See, for example, the Cluster reference for a complete list of attributes.

4.1. Access API entry point

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

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

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

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

The 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 is 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. List data centers

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

The following request retrieves a representation of the data centers:

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

The 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. 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

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

The following request retrieves the list of logical networks:

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

The 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. 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

The 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. 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. 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. 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>

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>
</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>

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>
</storage_domain>
' \
https://myengine.example.com/ovirt-engine/api/datacenters/001/storagedomains

4.9. 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>

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 '
<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. 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>

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 '
<nic>
  <name>mynic</name>
  <description>My network interface card</description>
</nic>
' \
https://myengine.example.com/ovirt-engine/api/vms/007/nics

4.11. 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>

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 '
<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. Attach ISO image to virtual machine

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

ISO images must be available in the myisos ISO domain for the virtual machines to use. You can use Section 6.123, “ImageTransfers” to create an image transfer and Section 6.122, “ImageTransfer” to upload the ISO image.

Once the ISO image 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

The 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 the 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>

The 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. 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>

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 '
<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.

Chapter 5. Requests

This section enumerates all the requests that are available in the API.

Chapter 6. Services

This section enumerates all the services that are available in the API.

6.1. AffinityGroup

This service manages a single affinity group.

Table 6.1. Methods summary

NameSummary

get

Retrieve the affinity group details.

remove

Remove the affinity group.

update

Update the affinity group.

6.1.1. get GET

Retrieve the affinity group details.

<affinity_group id="00000000-0000-0000-0000-000000000000">
  <name>AF_GROUP_001</name>
  <cluster id="00000000-0000-0000-0000-000000000000"/>
  <positive>true</positive>
  <enforcing>true</enforcing>
</affinity_group>

Table 6.2. Parameters summary

NameTypeDirectionSummary

follow

String

In

Indicates which inner links should be followed.

group

AffinityGroup

Out

The affinity group.

6.1.1.1. follow

Indicates which inner links should be followed. The objects referenced by these links will be fetched as part of the current request. See here for details.

6.1.2. remove DELETE

Remove the affinity group.

DELETE /ovirt-engine/api/clusters/000-000/affinitygroups/123-456

Table 6.3. Parameters summary

NameTypeDirectionSummary

async

Boolean

In

Indicates if the removal should be performed asynchronously.

6.1.3. update PUT

Update the affinity group.

Table 6.4. Parameters summary

NameTypeDirectionSummary

async

Boolean

In

Indicates if the update should be performed asynchronously.

group

AffinityGroup

In/Out

The affinity group.

6.2. AffinityGroupHost

This service manages a single host to affinity group assignment.

Table 6.5. Methods summary