[FAB-2295] Minor fixes to configtx template

1. Remove confusing comment on `NewChainCreationTemplate`.
2. Add comments to exported variables.
3. Extend test so that it checks policy name

Change-Id: Ica061bfcf82662f223ebdaa1dbe62423bc819dbe
Signed-off-by: Kostas Christidis <kostas@christidis.io>

common/configtx/template.go

@@ -30,26 +30,34 @@ import (
 )
 
 const (
+ // CreationPolicyKey defines the config key used in the channel
+ // config, under which the creation policy is defined.
  CreationPolicyKey = "CreationPolicy"
  msgVersion = int32(0)
  epoch = 0
 
+ // ApplicationGroup identifies the `groups` map key in the channel
+ // config, under which the application-related config group is set.
  ApplicationGroup = "Application"
- OrdererGroup = "Orderer"
- MSPKey = "MSP"
+ // OrdererGroup identifies the `groups` map key in the channel
+ // config, under which the orderer-related config group is set.
+ OrdererGroup = "Orderer"
+ // MSPKey identifies the config key in the channel config,
+ // under which the application-related config group is set.
+ MSPKey = "MSP"
 )
 
 // Template can be used to faciliate creation of config transactions
 type Template interface {
- // Items returns a set of ConfigUpdateEnvelopes for the given chainID
+ // Envelope returns a ConfigUpdateEnvelope for the given chainID
  Envelope(chainID string) (*cb.ConfigUpdateEnvelope, error)
 }
 
 type simpleTemplate struct {
  configGroup *cb.ConfigGroup
 }
 
-// NewSimpleTemplate creates a Template using the supplied ConfigGroup
+// NewSimpleTemplate creates a Template using the supplied ConfigGroups
 func NewSimpleTemplate(configGroups ...*cb.ConfigGroup) Template {
  sts := make([]Template, len(configGroups))
  for i, group := range configGroups {
@@ -60,7 +68,7 @@ func NewSimpleTemplate(configGroups ...*cb.ConfigGroup) Template {
  return NewCompositeTemplate(sts...)
 }
 
-// Envelope returns a ConfigUpdateEnvelopes for the given chainID
+// Envelope returns a ConfigUpdateEnvelope for the given chainID
 func (st *simpleTemplate) Envelope(chainID string) (*cb.ConfigUpdateEnvelope, error) {
  config, err := proto.Marshal(&cb.ConfigUpdate{
  Header: &cb.ChannelHeader{
@@ -83,7 +91,7 @@ type compositeTemplate struct {
  templates []Template
 }
 
-// NewSimpleTemplate creates a Template using the source Templates
+// NewCompositeTemplate creates a Template using the source Templates
 func NewCompositeTemplate(templates ...Template) Template {
  return &compositeTemplate{templates: templates}
 }
@@ -119,7 +127,7 @@ func copyGroup(source *cb.ConfigGroup, target *cb.ConfigGroup) error {
  return nil
 }
 
-// Envelope returns the ConfigUpdateEnvelope for the given chainID
+// Envelope returns a ConfigUpdateEnvelope for the given chainID
 func (ct *compositeTemplate) Envelope(chainID string) (*cb.ConfigUpdateEnvelope, error) {
  channel := cb.NewConfigGroup()
 
@@ -152,9 +160,8 @@ func (ct *compositeTemplate) Envelope(chainID string) (*cb.ConfigUpdateEnvelope,
  return &cb.ConfigUpdateEnvelope{ConfigUpdate: marshaledConfig}, nil
 }
 
-// NewChainCreationTemplate takes a CreationPolicy and a Template to produce a Template which outputs an appropriately
-// constructed list of ConfigUpdateEnvelope. Note, using this Template in
-// a CompositeTemplate will invalidate the CreationPolicy
+// NewChainCreationTemplate takes a CreationPolicy and a Template to produce a
+// Template which outputs an appropriately constructed list of ConfigUpdateEnvelopes.
 func NewChainCreationTemplate(creationPolicy string, template Template) Template {
  result := cb.NewConfigGroup()
  result.Groups[configtxorderer.GroupKey] = cb.NewConfigGroup()

common/configtx/template_test.go

@@ -20,8 +20,10 @@ import (
  "fmt"
  "testing"
 
+ "github.com/golang/protobuf/proto"
  configtxorderer "github.com/hyperledger/fabric/common/configtx/handlers/orderer"
  cb "github.com/hyperledger/fabric/protos/common"
+ ab "github.com/hyperledger/fabric/protos/orderer"
 
  "github.com/stretchr/testify/assert"
 )
@@ -102,6 +104,12 @@ func TestNewChainTemplate(t *testing.T) {
  assert.True(t, ok, "Expected to find %d but did not", i)
  }
 
- _, ok := configNext.WriteSet.Groups[configtxorderer.GroupKey].Values[CreationPolicyKey]
+ configValue, ok := configNext.WriteSet.Groups[configtxorderer.GroupKey].Values[CreationPolicyKey]
  assert.True(t, ok, "Did not find creation policy")
+
+ creationPolicyMessage := new(ab.CreationPolicy)
+ if err := proto.Unmarshal(configValue.Value, creationPolicyMessage); err != nil {
+ t.Fatal("Should not have errored:", err)
+ }
+ assert.Equal(t, creationPolicy, creationPolicyMessage.Policy, "Policy names don't match")
 }