[FAB-2408] Fix policies absolute paths

https://jira.hyperledger.org/browse/FAB-2408

While the policy manager was still in development, the absolute path
resolution for policies was handled in the configuration manager.  This
worked fine for config updates, but for other components of the system
such as those depending on the 'ChannelApplicationReaders', the absolute
paths did not work.

This CR pushes the absolute policy path resolution back into the policy
manager where it belongs.

Change-Id: Idcfa2ca030115b3ff9e3034f8c54767af1c2ea49
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

common/configtx/update.go

@@ -18,7 +18,6 @@ package configtx
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/hyperledger/fabric/common/policies"
 	cb "github.com/hyperledger/fabric/protos/common"
@@ -123,10 +122,6 @@ func (cm *configManager) authorizeUpdate(configUpdateEnv *cb.ConfigUpdateEnvelop
 }
 
 func (cm *configManager) policyForItem(item comparable) (policies.Policy, bool) {
-	if strings.HasPrefix(item.modPolicy(), PathSeparator) {
-		return cm.PolicyManager().GetPolicy(item.modPolicy()[1:])
-	}
-
 	// path is always at least of length 1
 	manager, ok := cm.PolicyManager().Manager(item.path[1:])
 	if !ok {

common/configtx/update_test.go

@@ -72,13 +72,4 @@ func TestPolicyForItem(t *testing.T) {
 	})
 	assert.True(t, ok)
 	assert.Equal(t, policy, fooPolicy, "Should not have found relative foo policy the foo manager")
-
-	policy, ok = cm.policyForItem(comparable{
-		path: []string{"root", "foo"},
-		ConfigValue: &cb.ConfigValue{
-			ModPolicy: "/rootPolicy",
-		},
-	})
-	assert.True(t, ok)
-	assert.Equal(t, policy, rootPolicy, "Should not have found absolute root policy from the foo path position")
 }

common/policies/policy.go

@@ -18,15 +18,25 @@ package policies
 
 import (
 	"fmt"
+	"strings"
 
 	cb "github.com/hyperledger/fabric/protos/common"
 
 	logging "github.com/op/go-logging"
 )
 
 const (
+	// Path separator is used to separate policy names in paths
+	PathSeparator = "/"
+
+	// ChannelPrefix is used in the path of standard channel policy managers
+	ChannelPrefix = "Channel"
+
+	// ApplicationPrefix is used in the path of standard application policy paths
+	ApplicationPrefix = "Application"
+
 	// ChannelApplicationReaders is the label for the channel's application readers policy
-	ChannelApplicationReaders = "/channel/Application/Readers"
+	ChannelApplicationReaders = "/" + ChannelPrefix + "/" + ApplicationPrefix + "/Readers"
 )
 
 var logger = logging.MustGetLogger("common/policies")
@@ -45,7 +55,7 @@ type Manager interface {
 	// Manager returns the sub-policy manager for a given path and whether it exists
 	Manager(path []string) (Manager, bool)
 
-	// Basepath returns the basePath the manager was instnatiated with
+	// Basepath returns the basePath the manager was instantiated with
 	BasePath() string
 
 	// Policies returns all policy names defined in the manager
@@ -78,7 +88,9 @@ type policyConfig struct {
 // ManagerImpl is an implementation of Manager and configtx.ConfigHandler
 // In general, it should only be referenced as an Impl for the configtx.ConfigManager
 type ManagerImpl struct {
+	parent        *ManagerImpl
 	basePath      string
+	fqPrefix      string
 	providers     map[int32]Provider
 	config        *policyConfig
 	pendingConfig *policyConfig
@@ -93,6 +105,7 @@ func NewManagerImpl(basePath string, providers map[int32]Provider) *ManagerImpl
 
 	return &ManagerImpl{
 		basePath:  basePath,
+		fqPrefix:  PathSeparator + basePath + PathSeparator,
 		providers: providers,
 		config: &policyConfig{
 			policies: make(map[string]Policy),
@@ -138,15 +151,36 @@ func (pm *ManagerImpl) Manager(path []string) (Manager, bool) {
 
 // GetPolicy returns a policy and true if it was the policy requested, or false if it is the default reject policy
 func (pm *ManagerImpl) GetPolicy(id string) (Policy, bool) {
-	policy, ok := pm.config.policies[id]
+	if id == "" {
+		logger.Errorf("Returning dummy reject all policy because no policy ID supplied")
+		return rejectPolicy(id), false
+	}
+	var relpath string
+
+	if strings.HasPrefix(id, PathSeparator) {
+		if pm.parent != nil {
+			return pm.parent.GetPolicy(id)
+		}
+		if !strings.HasPrefix(id, pm.fqPrefix) {
+			if logger.IsEnabledFor(logging.DEBUG) {
+				logger.Debugf("Requested policy from root manager with wrong basePath: %s, returning rejectAll", id)
+			}
+			return rejectPolicy(id), false
+		}
+		relpath = id[len(pm.fqPrefix):]
+	} else {
+		relpath = id
+	}
+
+	policy, ok := pm.config.policies[relpath]
 	if !ok {
 		if logger.IsEnabledFor(logging.DEBUG) {
-			logger.Debugf("Returning dummy reject all policy because %s could not be found in %s", id, pm.basePath)
+			logger.Debugf("Returning dummy reject all policy because %s could not be found in /%s/%s", id, pm.basePath, relpath)
 		}
-		return rejectPolicy(id), false
+		return rejectPolicy(relpath), false
 	}
 	if logger.IsEnabledFor(logging.DEBUG) {
-		logger.Debugf("Returning policy %s for evaluation", id)
+		logger.Debugf("Returning policy %s for evaluation", relpath)
 	}
 	return policy, true
 }
@@ -165,6 +199,7 @@ func (pm *ManagerImpl) BeginPolicyProposals(groups []string) ([]Proposer, error)
 	managers := make([]Proposer, len(groups))
 	for i, group := range groups {
 		newManager := NewManagerImpl(group, pm.providers)
+		newManager.parent = pm
 		pm.pendingConfig.managers[group] = newManager
 		managers[i] = newManager
 	}
@@ -184,7 +219,7 @@ func (pm *ManagerImpl) CommitProposals() {
 
 	for managerPath, m := range pm.pendingConfig.managers {
 		for _, policyName := range m.PolicyNames() {
-			fqKey := managerPath + "/" + policyName
+			fqKey := managerPath + PathSeparator + policyName
 			pm.pendingConfig.policies[fqKey], _ = m.GetPolicy(policyName)
 			logger.Debugf("In commit adding relative sub-policy %s to %s", fqKey, pm.basePath)
 		}
@@ -197,6 +232,20 @@ func (pm *ManagerImpl) CommitProposals() {
 
 	pm.config = pm.pendingConfig
 	pm.pendingConfig = nil
+
+	if pm.parent == nil && pm.basePath == ChannelPrefix {
+		if _, ok := pm.config.managers[ApplicationPrefix]; ok {
+			// Check for default application policies if the application component is defined
+			for _, policyName := range []string{ChannelApplicationReaders} {
+				_, ok := pm.GetPolicy(policyName)
+				if !ok {
+					logger.Warningf("Current configuration has no policy '%s', this will likely cause problems in production systems", policyName)
+				} else {
+					logger.Debugf("As expected, current configuration has policy '%s'", policyName)
+				}
+			}
+		}
+	}
 }
 
 // ProposePolicy takes key, path, and ConfigPolicy and registers it in the proposed PolicyManager, or errors

common/policies/policy_test.go

@@ -74,6 +74,7 @@ func TestUnnestedManager(t *testing.T) {
 
 func TestNestedManager(t *testing.T) {
 	m := NewManagerImpl("test", defaultProviders())
+	absPrefix := "/test/"
 	nesting1, err := m.BeginPolicyProposals([]string{"nest1"})
 	assert.NoError(t, err)
 	assert.Len(t, nesting1, 1, "Should not have returned exactly one additional manager")
@@ -137,6 +138,10 @@ func TestNestedManager(t *testing.T) {
 	for _, policyName := range policyNames {
 		_, ok := m.GetPolicy(policyName)
 		assert.True(t, ok, "Should have found policy %s", policyName)
+
+		absName := absPrefix + policyName
+		_, ok = m.GetPolicy(absName)
+		assert.True(t, ok, "Should have found absolute policy %s", absName)
 	}
 
 	for _, policyName := range n1PolicyNames {
@@ -145,6 +150,12 @@ func TestNestedManager(t *testing.T) {
 
 		_, ok = m.GetPolicy(n1.BasePath() + "/" + policyName)
 		assert.True(t, ok, "Should have found policy %s", policyName)
+
+		for i, abs := range []Manager{n1, m} {
+			absName := absPrefix + n1.BasePath() + "/" + policyName
+			_, ok = abs.GetPolicy(absName)
+			assert.True(t, ok, "Should have found absolutely policy for manager %d", i)
+		}
 	}
 
 	for _, policyName := range n2aPolicyNames {
@@ -156,6 +167,12 @@ func TestNestedManager(t *testing.T) {
 
 		_, ok = m.GetPolicy(n1.BasePath() + "/" + n2a.BasePath() + "/" + policyName)
 		assert.True(t, ok, "Should have found policy %s", policyName)
+
+		for i, abs := range []Manager{n2a, n1, m} {
+			absName := absPrefix + n1.BasePath() + "/" + n2a.BasePath() + "/" + policyName
+			_, ok = abs.GetPolicy(absName)
+			assert.True(t, ok, "Should have found absolutely policy for manager %d", i)
+		}
 	}
 
 	for _, policyName := range n2bPolicyNames {
@@ -167,5 +184,11 @@ func TestNestedManager(t *testing.T) {
 
 		_, ok = m.GetPolicy(n1.BasePath() + "/" + n2b.BasePath() + "/" + policyName)
 		assert.True(t, ok, "Should have found policy %s", policyName)
+
+		for i, abs := range []Manager{n2b, n1, m} {
+			absName := absPrefix + n1.BasePath() + "/" + n2b.BasePath() + "/" + policyName
+			_, ok = abs.GetPolicy(absName)
+			assert.True(t, ok, "Should have found absolutely policy for manager %d", i)
+		}
 	}
 }