[FAB-3831] Report empty application/orderer groups

The config interface currently returns the application/orderer config
groups as an interface definition.  Because of this, a simple nil check
will not generally determine whether the config is actually set, and
consequently attempting to access the config may cause a nil pointer
dereference (even when the nil check returns false).

This CR adds a bool to this interface, to allow the caller to determine
whether the interface has been populated.

Change-Id: I37e0ba25dcacffb273e5712f072d65786206b05b
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

common/configtx/api/api.go

@@ -59,14 +59,16 @@ type Resources interface {
 	ChannelConfig() config.Channel
 
 	// OrdererConfig returns the config.Orderer for the channel
-	OrdererConfig() config.Orderer
+	// and whether the Orderer config exists
+	OrdererConfig() (config.Orderer, bool)
 
 	// ConsortiumsConfig() returns the config.Consortiums for the channel
 	// and whether the consortiums config exists
 	ConsortiumsConfig() (config.Consortiums, bool)
 
 	// ApplicationConfig returns the configtxapplication.SharedConfig for the channel
-	ApplicationConfig() config.Application
+	// and whether the Application config exists
+	ApplicationConfig() (config.Application, bool)
 
 	// MSPManager returns the msp.MSPManager for the chain
 	MSPManager() msp.MSPManager

common/configtx/initializer.go

@@ -47,13 +47,21 @@ func (r *resources) ChannelConfig() config.Channel {
 }
 
 // OrdererConfig returns the api.OrdererConfig for the chain
-func (r *resources) OrdererConfig() config.Orderer {
-	return r.configRoot.Orderer()
+func (r *resources) OrdererConfig() (config.Orderer, bool) {
+	result := r.configRoot.Orderer()
+	if result == nil {
+		return nil, false
+	}
+	return result, true
 }
 
 // ApplicationConfig returns the api.ApplicationConfig for the chain
-func (r *resources) ApplicationConfig() config.Application {
-	return r.configRoot.Application()
+func (r *resources) ApplicationConfig() (config.Application, bool) {
+	result := r.configRoot.Application()
+	if result == nil {
+		return nil, false
+	}
+	return result, true
 }
 
 // ConsortiumsConfig returns the api.ConsortiumsConfig for the chain and whether or not

common/mocks/configtx/configtx.go

@@ -57,13 +57,13 @@ func (r *Resources) ChannelConfig() config.Channel {
 }
 
 // Returns the OrdererConfigVal
-func (r *Resources) OrdererConfig() config.Orderer {
-	return r.OrdererConfigVal
+func (r *Resources) OrdererConfig() (config.Orderer, bool) {
+	return r.OrdererConfigVal, r.OrdererConfigVal == nil
 }
 
 // Returns the ApplicationConfigVal
-func (r *Resources) ApplicationConfig() config.Application {
-	return r.ApplicationConfigVal
+func (r *Resources) ApplicationConfig() (config.Application, bool) {
+	return r.ApplicationConfigVal, r.ApplicationConfigVal == nil
 }
 
 func (r *Resources) ConsortiumsConfig() (config.Consortiums, bool) {

core/peer/peer.go

@@ -185,9 +185,14 @@ func createChain(cid string, ledger ledger.PeerLedger, cb *common.Block) error {
 	gossipEventer := service.GetGossipService().NewConfigEventer()
 
 	gossipCallbackWrapper := func(cm configtxapi.Manager) {
+		ac, ok := configtxInitializer.ApplicationConfig()
+		if !ok {
+			// TODO, handle a missing ApplicationConfig more gracefully
+			ac = nil
+		}
 		gossipEventer.ProcessConfigUpdate(&chainSupport{
 			Manager:     cm,
-			Application: configtxInitializer.ApplicationConfig(),
+			Application: ac,
 		})
 		service.GetGossipService().SuspectPeers(func(identity api.PeerIdentityType) bool {
 			// TODO: this is a place-holder that would somehow make the MSP layer suspect
@@ -214,9 +219,13 @@ func createChain(cid string, ledger ledger.PeerLedger, cb *common.Block) error {
 	// TODO remove once all references to mspmgmt are gone from peer code
 	mspmgmt.XXXSetMSPManager(cid, configtxManager.MSPManager())
 
+	ac, ok := configtxInitializer.ApplicationConfig()
+	if !ok {
+		ac = nil
+	}
 	cs := &chainSupport{
 		Manager:     configtxManager,
-		Application: configtxManager.ApplicationConfig(), // TODO, refactor as this is accessible through Manager
+		Application: ac, // TODO, refactor as this is accessible through Manager
 		ledger:      ledger,
 	}
 
@@ -386,10 +395,14 @@ func buildTrustedRootsForChain(cm configtxapi.Manager) {
 	ordererRootCAs := [][]byte{}
 	appOrgMSPs := make(map[string]struct{})
 
-	//loop through app orgs and build map of MSPIDs
-	for _, appOrg := range cm.ApplicationConfig().Organizations() {
-		appOrgMSPs[appOrg.MSPID()] = struct{}{}
+	ac, ok := cm.ApplicationConfig()
+	if ok {
+		//loop through app orgs and build map of MSPIDs
+		for _, appOrg := range ac.Organizations() {
+			appOrgMSPs[appOrg.MSPID()] = struct{}{}
+		}
 	}
+
 	cid := cm.ChainID()
 	peerLogger.Debugf("updating root CAs for channel [%s]", cid)
 	msps, err := cm.MSPManager().GetMSPs()
@@ -452,13 +465,15 @@ func GetMSPIDs(cid string) []string {
 		return mockMSPIDGetter(cid)
 	}
 	if c, ok := chains.list[cid]; ok {
-		if c == nil || c.cs == nil ||
-			c.cs.ApplicationConfig() == nil ||
-			c.cs.ApplicationConfig().Organizations() == nil {
+		if c == nil || c.cs == nil {
+			return nil
+		}
+		ac, ok := c.cs.ApplicationConfig()
+		if !ok || ac.Organizations() == nil {
 			return nil
 		}
 
-		orgs := c.cs.ApplicationConfig().Organizations()
+		orgs := ac.Organizations()
 		toret := make([]string, len(orgs))
 		i := 0
 		for _, org := range orgs {

orderer/multichain/manager.go

@@ -57,7 +57,11 @@ type configResources struct {
 }
 
 func (cr *configResources) SharedConfig() config.Orderer {
-	return cr.OrdererConfig()
+	oc, ok := cr.OrdererConfig()
+	if !ok {
+		logger.Panicf("[channel %s] has no orderer configuration", cr.ChainID())
+	}
+	return oc
 }
 
 type ledgerResources struct {