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Example Spec - The title of your blueprint

Include the URL of your launchpad blueprint:

Introduction paragraph -- why are we doing anything? A single paragraph of prose that operators can understand. The title and this first paragraph should be used as the subject line and body of the commit message respectively.

Some notes about using this template:

  • The aim of this document is first to define the problem we need to solve, and second agree the overall approach to solve that problem.
  • You should aim to get your spec approved before writing your code. While you are free to write prototypes and code before getting your spec approved, its possible that the outcome of the spec review process leads you towards a fundamentally different solution than you first envisaged.
  • Your spec should be in ReSTructured text, like this template.
  • Please wrap text at 79 columns.
  • The filename in the git repository should match the launchpad URL, for example: should be named awesome-thing.rst
  • Please do not delete any of the sections in this template. If you have nothing to say for a whole section, just write: None
  • For help with syntax, see
  • To test out your formatting, build the docs using tox and see the generated HTML file in doc/build/html/specs/<path_of_your_file>
  • If you would like to provide a diagram with your spec, ascii diagrams are required. is a very nice tool to assist with making ascii diagrams. The reason for this is that the tool used to review specs is based purely on plain text. Plain text will allow review to proceed without having to look at additional files which can not be viewed in gerrit. It will also allow inline feedback on the diagram itself.

Problem description

A detailed description of the problem. What problem is this blueprint addressing?

Use Cases

What use cases does this address? What impact on actors does this change have? Ensure you are clear about the actors in each use case: Developer, End User, Deployer etc.

Proposed change

Here is where you cover the change you propose to make in detail. How do you propose to solve this problem?

If this is one part of a larger effort make it clear where this piece ends. In other words, what's the scope of this effort?


What other ways could we do this thing? Why aren't we using those? This doesn't have to be a full literature review, but it should demonstrate that thought has been put into why the proposed solution is an appropriate one.

Security impact

Describe any potential security impact on the system. Some of the items to consider include:

  • Does this change touch sensitive data such as tokens, keys, or user data?
  • Does this change involve cryptography or hashing?
  • Does this change require the use of sudo or any elevated privileges?
  • Does this change involve using or parsing user-provided data? This could be directly at the API level or indirectly such as changes to a cache layer.
  • Can this change enable a resource exhaustion attack, such as allowing a single API interaction to consume significant server resources? Some examples of this include launching subprocesses for each connection, or entity expansion attacks in XML.

For more detailed guidance, please see the OpenStack Security Guidelines as a reference ( These guidelines are a work in progress and are designed to help you identify security best practices. For further information, feel free to reach out to the OpenStack Security Group at

End user impact

How would the end user be impacted by this change? The "End User" is defined as the users of the deployed cloud?

Performance Impact

Describe any potential performance impact on the system, for example how often will new code be called, and is there a major change to the calling pattern of existing code.

Examples of things to consider here include:

  • A small change in a utility function or a commonly used decorator can have a large impacts on performance.
  • Will the change include any locking, and if so what considerations are there on holding the lock?

Deployer impact

Discuss things that will affect how you deploy and configure OpenStack that have not already been mentioned, such as:

  • What config options are being added? Are the default values ones which will work well in real deployments?
  • Is this a change that takes immediate effect after its merged, or is it something that has to be explicitly enabled?
  • If this change is a new binary, how would it be deployed?
  • Please state anything that those doing continuous deployment, or those upgrading from the previous release, need to be aware of. Also describe any plans to deprecate configuration values or features.

Developer impact

Discuss things that will affect other developers working on the driver or OpenStack in general.



Who is leading the writing of the code? Or is this a blueprint where you're throwing it out there to see who picks it up?

If more than one person is working on the implementation, please designate the primary author and contact.

Primary assignee:

<launchpad-id or None>

Other contributors:

<launchpad-id or None>

Work Items

Work items or tasks -- break the feature up into the things that need to be done to implement it. Those parts might end up being done by different people, but we're mostly trying to understand the timeline for implementation.


  • Include specific references to specs/blueprints in networking-powervm, or in other projects, that this one either depends on or is related to. For example, a dependency on pypowervm changes should be documented here.
  • If this requires functionality of another project that is not currently used by networking-powervm document that fact.
  • Does this feature require any new library dependencies or code otherwise not included in OpenStack? Or does it depend on a specific version of library?


Please discuss the important scenarios needed to test here, as well as specific edge cases we should be ensuring work correctly. For each scenario please specify if this requires specialized hardware, a full openstack environment, etc.

Please discuss how the change will be tested. We especially want to know what functional tests will be added. It is assumed that unit test coverage will be added so that doesn't need to be mentioned explicitly.

Documentation Impact

Which audiences are affected most by this change, and which documentation titles should be updated because of this change? Don't repeat details discussed above, but reference them here in the context of documentation for multiple audiences.


Please add any useful references here. You are not required to have any reference. Moreover, this specification should still make sense when your references are unavailable. Examples of what you could include are:

  • Links to mailing list or IRC discussions
  • Links to notes from a summit session
  • Links to relevant research, if appropriate
  • Related specifications as appropriate
  • Anything else you feel it is worthwhile to refer to


Optional section intended to be used each time the spec is updated to describe new design.

Release Name Description
Mitaka Introduced