[FAB-10172] Extended Unit test for discovery

This change set adds an extended unit test for discovery, which:
- Uses production implementations of all discovery components, including
  the discovery support objects found under discovery/
- Uses production implementations of MSPs and real x509 identities
- Uses a real genesis block from configtxgen for config query testing
- Uses a mock gossip implementation
- Uses a mock ledger implementation, but a production lifecycle
  support (the object that intermediates between discovery and the ledger
  and is found under core/cclifecycle
- Uses real gRPC servers and clients with TLS.
  The gRPC servers listen to ephemeral ports, so we won't get
  a bind: already in use error in CI ;)

The test contains the following tests:

TestGreenPath: Tests all query types, specifically:
- cc2cc endorsers query and endorsers query with collections
- both channel and local peer query
- config query

TestRevocation:
- Queries once to warmup the cache
- Queries twice to ensure the underlying MSP isn't used
  because the ACL cache takes the hit
- Advances the config sequence and artificially revokes
  all identities in the MSP manager
- Queries thrice and sees that the cache isn't hit,
  and that "access denied" is returned

TestEndorsementComputationFailure:
- tests a case where the collection policy doesn't cover
  any possible principal set combination for endorsement

TestLedgerFailure:
- Tests that querying from the ledger fails in some of the keys

Change-Id: I717572e04c8f178ef10bd3807f707cf58da0b406
Signed-off-by: yacovm <yacovm@il.ibm.com>

discovery/api.go

@@ -27,6 +27,8 @@ type ConfigSequenceSupport interface {
 	ConfigSequence(channel string) uint64
 }
 
+//go:generate mockery -name GossipSupport -case underscore -output ../support/mocks/
+
 // GossipSupport aggregates abilities that the gossip module
 // provides to the discovery service, such as knowing information about peers
 type GossipSupport interface {

discovery/support/acl/support.go

@@ -141,6 +141,16 @@ func (s *DiscoverySupport) MSPOfPrincipal(principal *msp.MSPPrincipal) string {
 	return ""
 }
 
+//go:generate mockery -name ChannelPolicyManagerGetter -case underscore  -output ../mocks/
+
+// ChannelPolicyManagerGetter is a support interface
+// to get access to the policy manager of a given channel
+type ChannelPolicyManagerGetter interface {
+	// Returns the policy manager associated to the passed channel
+	// and true if it was the manager requested, or false if it is the default manager
+	Manager(channelID string) (policies.Manager, bool)
+}
+
 // NewChannelVerifier returns a new channel verifier from the given policy and policy manager getter
 func NewChannelVerifier(policy string, polMgr policies.ChannelPolicyManagerGetter) *ChannelVerifier {
 	return &ChannelVerifier{