EndpointManager and NodeManager Cells

[joamaki]

This PR adds cells for EndpointManager and NodeManager (cilium-agent objects snippet):

          Ⓜ️ endpoint-manager (Manages the collection of local endpoints):
              ⚙️ (endpointmanager.EndpointManagerConfig) {
                  EndpointGCInterval: (time.Duration) 5m0s
              }

              🚧 endpointmanager.newDefaultEndpointManager (cell.go:177):
                  ⇨ client.Clientset, endpointmanager.EndpointManagerConfig, hive.Lifecycle
                  ⇦ endpointmanager.EndpointManager, endpointmanager.EndpointsLookup, 
                      endpointmanager.EndpointsModify

          Ⓜ️ node-manager (Manages the collection of Cilium nodes):
              🚧 manager.newAllNodeManager (cell.go:69):
                  ⇨ hive.Lifecycle
                  ⇦ manager.NodeManager

The endpoint manager is now exposed as 3 different APIs: EndpointsLookup (for read-only lookups of endpoints), EndpointsModify (for adding and removing endpoints), and EndpointManager (for initialization and operations on all endpoints). This division by functionality adds clarity ("ah this module only needs to look up endpoints") and makes integration testing of cells depending on e.g. endpoint lookup simpler.

Node manager's API is kept as in one chunk as it's relatively small. It is still exposed as an interface rather than as struct pointer, again for improved integration testing and for clarity. Providing interfaces at the cell-level does not go against the "return structs, accept interfaces" rule. That rule is all about loose coupling in public APIs, e.g. library functions should be flexible in what they accept (don't take *os.File, but io.Reader). Here we're following the same spirit, but at the macro level. With interfaces in the object graph we can choose the implementation to provide to a cell or augment an existing one (cell.Decorate) if needed. This gives maximum flexibility and loose coupling that comes especially handy in integration testing.

[joamaki]

/test

Job 'Cilium-PR-K8s-1.24-kernel-5.4' failed:

Click to show.

Test Name

K8sDatapathConfig Host firewall With VXLAN and endpoint routes

Failure Output

FAIL: Failed to reach 10.0.0.32:80 from testclient-host-22plg

If it is a flake and a GitHub issue doesn't already exist to track it, comment /mlh new-flake Cilium-PR-K8s-1.24-kernel-5.4 so I can create one.

[dylandreimerink]

Very nice, like the separate interfaces. Can't find anything to complain about.

[joamaki]

/test

[christarazi]

Nice, thanks. One comment below about root context passing. Otherwise LGTM.

[joamaki]

/test

[joamaki]

@tommyp1ckles addressed your comments about the method comments. Your comments about the API itself were good, but I wouldn't want to change the existing API in this PR as this is only about wrapping the endpoint manager into a module and lifting it outside Daemon struct.

[tommyp1ckles]

@tommyp1ckles addressed your comments about the method comments. Your comments about the API itself were good, but I wouldn't want to change the existing API in this PR as this is only about wrapping the endpoint manager into a module and lifting it outside Daemon struct.

Sounds good, seeing the interface written for these is a good opportunity to see where we can improve things. Everything LGTM, thanks!

[sayboras]

I assume we need to apply this pattern for other subsystems steadily ✔️

[joamaki]

/test

[joamaki]

test-runtime hit #19093, which is unrelated to changes. Marking ready.