Update Emergency Tier's Priority to 50

[abhiraut]

This PR updates the priority of Tiers created by Antrea, and space them out evenly. The current Antrea generated Tier priorities do not allow enough room for user defined Tiers to be created, for example Emergency Tier allows only 4 user created Tiers with higher priority. Since it ultimately is up to the users as to which Tiers go atop and the purpose of Antrea created Tiers is mainly that of convenience, we decided to distribute the priorities more evenly across available priority space. For example, setting the priority of the top most Tier of Emergency to a value of 50 gives enough room for admins to create their own Tier hierarchy without having to rely on Antrea created Tiers.

Summary of change:

Tier Name        Old Priority        Updated Priority
emergency         5                         50
securityops       50                        100
networkops        100                       150
platform          150                       200

NOTE: Existing users of Antrea created Tiers are advised to re-evaluate their Tier hierarchy and take action to recreate any user created Tier resource, such that they continue to be enforced as per user's intention.

[codecov-io]

Codecov Report

Merging #1665 (470dc8e) into master (9d3d10b) will increase coverage by 0.46%.
The diff coverage is 56.75%.

@@            Coverage Diff             @@
##           master    #1665      +/-   ##
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+ Coverage   63.31%   63.78%   +0.46%     
==========================================
  Files         170      181      +11     
  Lines       14250    16072    +1822     
==========================================
+ Hits         9023    10252    +1229     
- Misses       4292     4772     +480     
- Partials      935     1048     +113     

Flag	Coverage Δ
e2e-tests	45.77% <31.70%> (?)
kind-e2e-tests	53.64% <53.38%> (-1.75%)	⬇️
unit-tests	40.60% <28.68%> (-0.68%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/antrea-agent/agent.go	0.00% <0.00%> (ø)
.../agent/apiserver/handlers/networkpolicy/handler.go	58.33% <ø> (ø)
...gent/controller/noderoute/node_route_controller.go	60.98% <0.00%> (+14.51%)	⬆️
pkg/agent/stats/collector.go	97.72% <ø> (ø)
pkg/antctl/antctl.go	100.00% <ø> (ø)
pkg/antctl/transform/controllerinfo/transform.go	0.00% <ø> (ø)
pkg/antctl/transform/version/transform.go	0.00% <ø> (ø)
pkg/controller/types/networkpolicy.go	100.00% <ø> (ø)
pkg/features/antrea_features.go	16.66% <ø> (ø)
pkg/ovs/openflow/ofctrl_builder.go	60.94% <0.00%> (-1.23%)	⬇️
... and 111 more

[antoninbas]

I think it would be good to add the rationale for this change in the commit message / PR description.

Also it seems that in case of an Antrea update, the priority for the emergency tier will stay the same (at 5) and not be updated (to 20). Is that acceptable?

[abhiraut]

I think it would be good to add the rationale for this change in the commit message / PR description.

Also it seems that in case of an Antrea update, the priority for the emergency tier will stay the same (at 5) and not be updated (to 20). Is that acceptable?

apologies i wanted to keep it WIP. im thinking of force update priority to 20 for existing Emergency Tiers. However, that has the inherent issue of it being demoted below other user created CRDs whose priority lies between 6-19. I am wondering if that is acceptable. May need a release note.

[jianjuns]

How many tiers in total we support?
Feel something like {50, 100, 150, 200} sounds better, but maybe you want to change all tiers.

[abhiraut]

This PR updates the priority of Emergency Tier created by Antrea, and set it to 20 as opposed to the intially assigned value of
5. The current Antrea generated Emergency Tier priority of 5 does not allow enough room for user defined Tiers to be created
with higher priority, as ultimately it is up to the users as to which Tiers go atop and the purpose of Antrea created Tiers is
mainly that of convenience. Setting the priority of the top most Tier of Emergency to a value of 20 gives enough room for
admins to create their own Tier hierarchy without having to rely on Antrea created Tiers.

How many tiers in total we support?
Feel something like {50, 100, 150, 200} sounds better, but maybe you want to change all tiers.

Theoretically we can support up to 255. Practically we put a soft limit of 20 Tiers, but this limit of 20 can be relaxed with a single LOC change in validation.

Current Tier priorities after this change is as follows:

emergency     20         
securityops   50         
networkops    100        
platform      150        
application   250        

we could do:

emergency     50         
securityops   100         
networkops    150        
platform      200        
application   250        

Let me know if you prefer to keep proposal 1 or change to proposal 2.

[jianjuns]

Ok. Seems I missed application tier. Any reason we go from 150 to 200 for application tier today?

This combination looks easier to understand for me:
emergency 50
securityops 100
networkops 150
platform 200
application 250

[antoninbas]

Not a big fan of a change like this, but I guess it can be good to have more evenly-spaced out system tier priorities, and the API is still in alpha.

[Dyanngg]

The PR description also needs update

[abhiraut]

/test-all

[antoninbas]

Some nits, otherwise LGTM

Maybe @tnqn would like to take a quick look in case he has comments on the userInfo approach I suggested?

[jianjuns]

LGTM

[abhiraut]

/test-all

[antoninbas]

LGTM

[abhiraut]

/test-all

[tnqn]

LGTM