[FAB-2912] Undo base16-encoding for channel names

https://jira.hyperledger.org/browse/FAB-2912

The Kafka-based orderer would base16-encode channel names as a temporary
workaround for escaping illegal characters in Kafka [1].

With the filtering added in FAB-1349 [2], this kind of workaround is not
longer needed.

This changeset removes the workaround.

[1]
https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/common/Topic.scala#L29
[2] https://jira.hyperledger.org/browse/FAB-1349

Change-Id: I312222924e41cc8a1cf869c1bb3f650448e2f3d5
Signed-off-by: Kostas Christidis <kostas@christidis.io>

orderer/kafka/chain_partition.go

@@ -35,8 +35,7 @@ type chainPartitionImpl struct {
 // Returns a new chain partition for a given chain ID and partition.
 func newChainPartition(chainID string, partition int32) ChainPartition {
 	return &chainPartitionImpl{
-		// TODO https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/common/Topic.scala#L29
-		tpc: fmt.Sprintf("%x", chainID),
+		tpc: fmt.Sprintf("%s", chainID),
 		prt: partition,
 	}
 }

orderer/kafka/chain_partition_test.go

@@ -27,7 +27,7 @@ import (
 func TestChainPartition(t *testing.T) {
 	cp := newChainPartition(provisional.TestChainID, rawPartition)
 
-	expectedTopic := fmt.Sprintf("%x", provisional.TestChainID)
+	expectedTopic := fmt.Sprintf("%s", provisional.TestChainID)
 	actualTopic := cp.Topic()
 	if strings.Compare(expectedTopic, actualTopic) != 0 {
 		t.Fatalf("Got the wrong topic, expected %s, got %s instead", expectedTopic, actualTopic)

orderer/multichain/chainsupport.go

@@ -128,13 +128,13 @@ func newChainSupport(
 	// Assuming a block created with cb.NewBlock(), this should not
 	// error even if the orderer metadata is an empty byte slice
 	if err != nil {
-		logger.Fatalf("Error extracting orderer metadata for chain %x: %s", cs.ChainID(), err)
+		logger.Fatalf("[channel: %s] Error extracting orderer metadata: %s", cs.ChainID(), err)
 	}
-	logger.Debugf("Retrieved metadata for tip of chain (block #%d): %+v", cs.Reader().Height()-1, metadata)
+	logger.Debugf("[channel: %s] Retrieved metadata for tip of chain (block #%d): %+v", cs.ChainID(), cs.Reader().Height()-1, metadata)
 
 	cs.chain, err = consenter.HandleChain(cs, metadata)
 	if err != nil {
-		logger.Fatalf("Error creating consenter for chain %x: %s", ledgerResources.ChainID(), err)
+		logger.Fatalf("[channel: %s] Error creating consenter: %s", cs.ChainID(), err)
 	}
 
 	return cs
@@ -254,7 +254,7 @@ func (cs *chainSupport) WriteBlock(block *cb.Block, committers []filter.Committe
 
 	err := cs.ledger.Append(block)
 	if err != nil {
-		logger.Panicf("Could not append block: %s", err)
+		logger.Panicf("[channel: %s] Could not append block: %s", cs.ChainID(), err)
 	}
 	return block
 }

orderer/multichain/manager.go

@@ -110,7 +110,7 @@ func NewManagerImpl(ledgerFactory ledger.Factory, consenters map[string]Consente
 			// We delay starting this chain, as it might try to copy and replace the chains map via newChain before the map is fully built
 			defer chain.start()
 		} else {
-			logger.Debugf("Starting chain: %x", chainID)
+			logger.Debugf("Starting chain: %s", chainID)
 			chain := newChainSupport(createStandardFilters(ledgerResources),
 				ledgerResources,
 				consenters,