Open Stack

Hi folks!

Recently a problem that network check does not tell whether there’s enough IP addresses in a public network [1] was reported. That check is performed by CheckBeforeDeployment task, but there is two problems that happen because this verification is done that late:

 - A deployment fails, if there’s not enough addresses in specified ranges
 - If a user wants to get network configuration they will get an error

The solution for this problems seems to be easy and a straightforward patch [2] was proposed. However, there is a hidden problem which is that patch does not address which is that installed plugins may reserve VIPs for their needs. The issue is that they do it just before deployment and so it’s not possible to get those reservations when a user wants to check their network set up.

The important issue we have to address here is that network configuration generator will fail, if specified ranges don’t fit all VIPs. There were several proposals to fix that, I’d like to highlight two of them:

 a) Allow VIPs to not have an IP address assigned, if network config generator works for API output.
     That will prevent GET requests from failure, but since IP addresses for VIPs are required, generator will have to fail, if it generates a configuration for the orchestrator.
 b) Add a release note that users have to calculate IP addresses manually and put sane ranges in order to not shoot their own legs. Then it’s also possible to change network verification output to remind users to check the ranges before starting a deployment.

In my opinion we cannot follow (a) because it only masks a problem instead of providing a fix. Also it requires to change the API which is not a good thing to do after the SCF. If we choose (b), then we can work on a firm solution in 8.0 and fix the problem for real.


P. S. We can still merge [2], because it checks, if IP ranges can at least fit the basic configuration. If you agree, I will update it soon.

[1] https://bugs.launchpad.net/fuel/+bug/1487996
[2] https://review.openstack.org/#/c/217267/



- romcheg



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