Add forwarder reuse

[NikitaSkrynnik]

Signed-off-by: Nikita Skrynnik nikita.skrynnik@xored.com

Description

Issue link

#1230

How Has This Been Tested?

• Added unit testing to cover
• Tested manually
• Tested by integration testing
• Have not tested

Types of changes

• Bug fix
• New functionallity
• Documentation
• Refactoring
• CI

[denis-tingaikin]

Suggested change

	segments := request.Connection.GetPath().GetPathSegments()
	if pathIndex := int(request.Connection.GetPath().Index); len(segments) > pathIndex+1 {
	datapathForwarder := segments[pathIndex+1].Name
	for i, candidate := range nses {
	if candidate.Name == datapathForwarder {
	nses[0], nses[i] = nses[i], nses[0]
	break
	}
	}
	}

[denis-tingaikin]

I would suggest adding this at line 69

	if forwarderName == "" {
		segments := request.Connection.GetPath().GetPathSegments()
		if pathIndex := int(request.Connection.GetPath().Index); len(segments) > pathIndex+1 {
			forwarderName = segments[pathIndex+1].Name
		}
	}

[denis-tingaikin]

I feel this might be fixed by a suggestion from the previous comment.

Suggested change

	_, err = domain.Nodes[nodeNum].NSMgr.NetworkServiceEndpointRegistryServer().Register(ctx, &registry.NetworkServiceEndpoint{
	Name: expectedForwarderName,
	Url: domain.Nodes[nodeNum].Forwarders[expectedForwarderName].URL.String(),
	NetworkServiceNames: []string{"forwarder"},
	NetworkServiceLabels: map[string]*registry.NetworkServiceLabels{
	"forwarder": {
	Labels: map[string]string{
	"p2p": "true",
	},
	},
	},
	})
	require.NoError(t, err)
	_, err = domain.Nodes[nodeNum].NSMgr.NetworkServiceEndpointRegistryServer().Register(ctx, &registry.NetworkServiceEndpoint{
	Name: nseReg.Name,
	Url: nseEntry.URL.String(),
	NetworkServiceNames: nseReg.NetworkServiceNames,
	})
	require.NoError(t, err)
	}

[denis-tingaikin]

@NikitaSkrynnik Please note: in case of death we can down into infinity loop. I.e.

1. discoverfowarder gets refresh
2. the previously selected fowrarder dies

actual: discoverforwarder never reselects forwarder.
expected: discoverforwarder reselects forwarder if it is not registered.

So in case if forwarderName is empty we should try to re-use the name, but if it is not possible we should do reselection.