Merge "[FAB-6069] Add capabilities package to common"

common/capabilities/capabilities.go

@@ -0,0 +1,56 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package capabilities
+
+import (
+	"github.com/hyperledger/fabric/common/flogging"
+	cb "github.com/hyperledger/fabric/protos/common"
+
+	"github.com/pkg/errors"
+)
+
+const pkgLogID = "common/capabilities"
+
+var logger = flogging.MustGetLogger(pkgLogID)
+
+// provider is the 'plugin' parameter for registry.
+type provider interface {
+	// HasCapability should report whether the binary supports this capability.
+	HasCapability(capability string) bool
+
+	// Type is used to make error messages more legible.
+	Type() string
+}
+
+// registry is a common structure intended to be used to support specific aspects of capabilities
+// such as orderer, application, and channel.
+type registry struct {
+	provider     provider
+	capabilities map[string]*cb.Capability
+}
+
+func newRegistry(p provider, capabilities map[string]*cb.Capability) *registry {
+	return &registry{
+		provider:     p,
+		capabilities: capabilities,
+	}
+}
+
+// Supported checks that all of the required capabilities are supported by this binary.
+func (r *registry) Supported() error {
+	for capabilityName, capability := range r.capabilities {
+		if r.provider.HasCapability(capabilityName) {
+			continue
+		}
+
+		if capability.Required {
+			return errors.Errorf("%s capability %s is required but not supported", r.provider.Type(), capabilityName)
+		}
+		logger.Debugf("Found unknown %s capability %s but it is not required", r.provider.Type(), capabilityName)
+	}
+	return nil
+}

common/capabilities/capabilities_test.go

@@ -0,0 +1,60 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package capabilities
+
+import (
+	"testing"
+
+	cb "github.com/hyperledger/fabric/protos/common"
+
+	"github.com/op/go-logging"
+	"github.com/stretchr/testify/assert"
+)
+
+func init() {
+	logging.SetLevel(logging.DEBUG, pkgLogID)
+}
+
+func TestSatisfied(t *testing.T) {
+	t.Run("NilCapabilities", func(t *testing.T) {
+		var capsMap map[string]*cb.Capability
+		for _, provider := range []*registry{
+			NewChannelProvider(capsMap).registry,
+		} {
+			assert.Nil(t, provider.Supported())
+		}
+	})
+
+	t.Run("NotRequiredCapabilities", func(t *testing.T) {
+		capsMap := map[string]*cb.Capability{
+			"FakeCapability1": &cb.Capability{
+				Required: false,
+			},
+			"FakeCapability2": &cb.Capability{
+				Required: false,
+			},
+		}
+		for _, provider := range []*registry{
+			NewChannelProvider(capsMap).registry,
+		} {
+			assert.Nil(t, provider.Supported())
+		}
+	})
+}
+
+func TestNotSatisfied(t *testing.T) {
+	capsMap := map[string]*cb.Capability{
+		"FakeCapability": &cb.Capability{
+			Required: true,
+		},
+	}
+	for _, provider := range []*registry{
+		NewChannelProvider(capsMap).registry,
+	} {
+		assert.Error(t, provider.Supported())
+	}
+}

common/capabilities/channel.go

@@ -0,0 +1,41 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package capabilities
+
+import (
+	cb "github.com/hyperledger/fabric/protos/common"
+)
+
+const (
+	channelTypeName = "Channel"
+)
+
+// ChannelProvider provides capabilities information for channel level config.
+type ChannelProvider struct {
+	*registry
+}
+
+// NewChannelProvider creates a channel capabilities provider.
+func NewChannelProvider(capabilities map[string]*cb.Capability) *ChannelProvider {
+	cp := &ChannelProvider{}
+	cp.registry = newRegistry(cp, capabilities)
+	return cp
+}
+
+// Type returns a descriptive string for logging purposes.
+func (cp *ChannelProvider) Type() string {
+	return channelTypeName
+}
+
+// HasCapability returns true if the capability is supported by this binary.
+func (cp *ChannelProvider) HasCapability(capability string) bool {
+	switch capability {
+	// Add new capability names here
+	default:
+		return false
+	}
+}