VMware VCLOUD API 1.0 - TECHNICAL NOTE, Руководство по программированию

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VMware, Inc. 203
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The Open Virtualization Format (OVF) is an open, portable, efficient and extensible format for packaging and
distributing virtual systems. OVF was developed by the Distributed Management Task Force (DMTF), a
not ‐ for ‐ profit association of industry members dedicated to promoting enterprise and systems management
and interoperability. For more information about the DMTF and OVF, visit http://www.dmtf.org .
The vCloud API supports Version 1 of the OVF standard. In particular, it supports uploading and
downloading vApp templates as OVF packages. In addition, vApp, Vm, and vAppTemplate elements
incorporate a number of ovf:Section_Type elements in their definitions of virtual machines (see “Section”
on page 163 for details on how these sections are used).
This appendix includes the following topics:

“About OVF” on page 203

“How the vCloud API Uses OVF” on page 204
About OVF
Because it is a widely accepted standard format, OVF provides considerable flexibility in accommodating the
needs of a diverse collection of virtualization technologies. While this flexibility entails more complexity than
a vendor ‐ specific format might require, it also provides many advantages.

Virtual machines and appliances are distributed as OVF packages by many vendors.

Many vendors, including VMware, offer tools that simplify creating and customizing OVF virtual
machines, support converting virtual machines on existing virtualization platforms to OVF, or both.

OVF has the power to express the complex relationships between virtual appliances in enterprise
applications. Most of the complexity can be handled by the author of the appliance rather than the user
deploying it.

OVF is extensible, allowing new policies and requirements to be inserted by ISVs and implemented by
the virtualization platforms that support them without requiring changes to other clients, other platforms,
or the vCloud API itself.
While most users do not need to interact directly with the OVF ‐ derived elements of the vCloud API,
administrators and advanced users should become familiar with the details of the OVF standard before
developing applications with the vCloud API. This chapter provides an overview of OVF, one that
concentrates on the aspects of the standard that are of special interest to users of the vCloud API. The complete
OVF specification document is available at
http://www.dmtf.org/standards/published_documents/DSP0243_1.0.0.pdf . An informative white paper on
OVF is available at http://www.dmtf.org/standards/published_documents/DSP2017_1.0.0.pdf .
OVF and the vCloud API
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The vCloud API supports uploading OVF 1.0 and OVF 1.1, and downloading OVF 1.0. OVF 1.1
packages are converted to OVF 1.0 for download.