5.5

Table Of Contents
Deploying and Operating vApps 5
The vCloud API supports programmatic access to a range of self-service datacenter operations that allow
users to create, configure, deploy, and operate vApps.
The initial configuration of a vApp is established in the OVF package on which its source template is based.
In the vCloud API, vApp templates are based on OVF 1.0. These templates can be retrieved from catalogs
and transformed into virtual systems, called vApps, through a process called instantiation, which binds a
template’s abstract resource requirements to resources available in a VDC.
About OVF
OVF is a widely accepted standard format that applies to many virtualization technologies.
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Virtual machines and appliances are distributed as OVF packages by many vendors.
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Many vendors, including VMware, offer tools that simplify creating and customizing OVF, support
converting virtual machines on existing virtualization platforms to OVF, or both.
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OVF can express the complex relationships between virtual appliances in enterprise applications. The
author of the appliance can handle most of the complexity, rather than the user who deploys it.
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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.
Administrators and advanced users should become familiar with the details of the OVF standard before
developing applications with 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.
A virtual machine is typically made up of one or more virtual disk files that contain the operating system
and applications that run on the virtual machine, and a configuration file containing metadata that describe
how the virtual machine is configured and deployed. An OVF package includes these components, as well
as optional certificate and manifest files. The package can be distributed and stored as a collection of
individual files, or as a single archive (OVA) file. The vCloud API does not support uploading or
downloading OVA files.
vApp Life Cycle
A vApp contains one or more Vm elements, which represent individual virtual machines. It also contains
information that defines operational details for the vApp and the virtual machines that it contains. The
vApp lifecycle includes several distinct states:
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An OVF package, the form in which vApps are typically distributed.
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A vApp template, created when a client uploads an OVF package to a catalog.
VMware, Inc.
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