Add 'default_security_group' method to CloudTenant

[mansam]

Adds a default_security_group instance method to CloudTenant that returns a security group named default if that CloudTenant has one, or else returns the security group with the highest population of VMs.

[miq-bot]

Checked commit mansam@2ec415b with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 3 offenses detected

spec/models/manageiq/providers/openstack/cloud_manager/cloud_tenant_spec.rb

• ⚠️ - Line 37, Col 9 - Lint/UselessAssignment - Useless assignment to variable - test01. Did you mean test02?
• ⚠️ - Line 45, Col 9 - Lint/UselessAssignment - Useless assignment to variable - test03. Did you mean test01?
• ⚠️ - Line 8, Col 9 - Lint/UselessAssignment - Useless assignment to variable - test01. Did you mean test02?

[aufi]

Looks good to me, merging 👍

[Ladas]

btw. this looks pretty inefficient, there can be a lot of security groups

[kbrock]

This method is really bad. the large number of security groups and then the N+1 count for each of the vm counts is really bad.

Also, making this a virtual attribute means it is exposed for everyone - it probably needs to move to the core

It still is a bunch of work, but at least is done on the database:
security_groups.order(:total_vms).last

I'll ping @Ladas

[mansam]

@Ladas @kbrock Ordering via security_groups.order(:total_vms) throws an exception -- missing method 'asc' for NilClass, at least in my rails console. I'm working on writing a better join since this indeed isn't efficient enough.

[kbrock]

@mansam thanks - will look into that

[kbrock]

@mansam you are right - it looks like that is using a :through which currently does not handle this abstraction.

Will try and think up another way to avoid the N+1 queries