Add NetworkPolicy metrics API and controlplane stats API

[tnqn]

This PR introduces a control-plane API NodeStatsSummary for stats
collection and a public metrics API group including the following APIs:

• NetworkPolicyMetrics
• AntreaClusterNetworkPolicyMetrics
• AntreaNetworkPolicyMetrics

For #985

[antrea-bot]

Thanks for your PR.
Unit tests and code linters are run automatically every time the PR is updated.
E2e, conformance and network policy tests can only be triggered by a member of the vmware-tanzu organization. Regular contributors to the project should join the org.

The following commands are available:

• /test-e2e: to trigger e2e tests.
• /skip-e2e: to skip e2e tests.
• /test-conformance: to trigger conformance tests.
• /skip-conformance: to skip conformance tests.
• /test-whole-conformance: to trigger all conformance tests on linux.
• /skip-whole-conformance: to skip all conformance tests on linux.
• /test-networkpolicy: to trigger networkpolicy tests.
• /skip-networkpolicy: to skip networkpolicy tests.
• /test-windows-conformance: to trigger windows conformance tests.
• /skip-windows-conformance: to skip windows conformance tests.
• /test-windows-networkpolicy: to trigger windows networkpolicy tests.
• /skip-windows-networkpolicy: to skip windows networkpolicy tests.
• /test-hw-offload: to trigger ovs hardware offload test.
• /skip-hw-offload: to skip ovs hardware offload test.
• /test-all: to trigger all tests (except whole conformance).
• /skip-all: to skip all tests (except whole conformance).

[codecov-commenter]

Codecov Report

Merging #1221 into master will decrease coverage by 0.03%.
The diff coverage is 53.57%.

@@            Coverage Diff             @@
##           master    #1221      +/-   ##
==========================================
- Coverage   55.04%   55.01%   -0.04%     
==========================================
  Files         110      113       +3     
  Lines       10597    10625      +28     
==========================================
+ Hits         5833     5845      +12     
- Misses       4190     4205      +15     
- Partials      574      575       +1     

Flag	Coverage Δ
#integration-tests	44.90% <53.57%> (+<0.01%)	⬆️
#unit-tests	41.89% <ø> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
pkg/apis/metrics/register.go	0.00% <0.00%> (ø)
...ntroller/networkpolicy/networkpolicy_controller.go	72.41% <ø> (+0.13%)	⬆️
pkg/apis/controlplane/v1alpha1/register.go	83.33% <83.33%> (ø)
pkg/apis/metrics/v1alpha1/register.go	90.90% <90.90%> (ø)
pkg/apiserver/storage/ram/watch.go	84.61% <0.00%> (-3.85%)	⬇️
pkg/ovs/openflow/ofctrl_bridge.go	67.98% <0.00%> (-0.80%)	⬇️

[tnqn]

/test-all

[tnqn]

@jianjuns @antoninbas Because of a conflict with #1258 in types.go and I need both changes to support NetworkPolicyMetrics, I rebased this on #1258, the real change in this PR is a19d7ce.

[tnqn]

Only rebased on master after #1258 was merged.

[tnqn]

/test-all

[tnqn]

/test-windows-networkpolicy

[lzhecheng]

/test-windows-networkpolicy

[tnqn]

/test-windows-networkpolicy

[tnqn]

/test-windows-networkpolicy

[ceclinux]

Could you explain why pkg/apis/metrics/types.go is needed and get installed in pkg/apis/metrics/install/install.go? I think these are redundant. @tnqn

[tnqn]

Could you explain why pkg/apis/metrics/types.go is needed and get installed in pkg/apis/metrics/install/install.go? I think these are redundant. @tnqn

@ceclinux please take a look at https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api_changes.md which explains why an internal version is required. Actually it's not a must right now but will be needed once we have another API version.

[ceclinux]

Could you explain why pkg/apis/metrics/types.go is needed and get installed in pkg/apis/metrics/install/install.go? I think these are redundant. @tnqn

@ceclinux please take a look at https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api_changes.md which explains why an internal version is required. Actually it's not a must right now but will be needed once we have another API version.

Thanks for your reply