[FAB-7610] Print orderer parameters during boot time.

Change-Id: I11e66a55ebd526a36e310036891ec9f3204a8073 Signed-off-by: Jay Guo <guojiannan1101@gmail.com>
hyperledger · Jan 10, 2018 · 130dfef · 130dfef
1 parent 91340fe
commit 130dfef
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Showing 3 changed files with 115 additions and 0 deletions.
diff --git a/common/util/utils.go b/common/util/utils.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io"
 	"math/big"
+	"reflect"
 	"strings"
 	"time"
 
@@ -193,3 +194,59 @@ func ConcatenateBytes(data ...[]byte) []byte {
 	}
 	return result
 }
+
+// `flatten` recursively retrieves every leaf node in a struct in depth-first fashion
+// and aggregate the results into given string slice with format: "path.to.leaf = value"
+// in the order of definition. Root name is ignored in the path. This helper function is
+// useful to pretty-print a struct, such as configs.
+// for example, given data structure:
+// A{
+//   B{
+//     C: "foo",
+//     D: 42,
+//   },
+//   E: nil,
+// }
+// it should yield a slice of string containing following items:
+// [
+//   "B.C = \"foo\"",
+//   "B.D = 42",
+//   "E =",
+// ]
+func Flatten(i interface{}) []string {
+	var res []string
+	flatten("", &res, reflect.ValueOf(i))
+	return res
+}
+
+const DELIMITER = "."
+
+func flatten(k string, m *[]string, v reflect.Value) {
+	delimiter := DELIMITER
+	if k == "" {
+		delimiter = ""
+	}
+
+	switch v.Kind() {
+	case reflect.Ptr:
+		if v.IsNil() {
+			*m = append(*m, fmt.Sprintf("%s =", k))
+			return
+		}
+		flatten(k, m, v.Elem())
+	case reflect.Struct:
+		if x, ok := v.Interface().(fmt.Stringer); ok {
+			*m = append(*m, fmt.Sprintf("%s = %v", k, x))
+			return
+		}
+
+		for i := 0; i < v.NumField(); i++ {
+			flatten(k+delimiter+v.Type().Field(i).Name, m, v.Field(i))
+		}
+	case reflect.String:
+		// It is useful to quote string values
+		*m = append(*m, fmt.Sprintf("%s = \"%s\"", k, v))
+	default:
+		*m = append(*m, fmt.Sprintf("%s = %v", k, v))
+	}
+}
diff --git a/common/util/utils_test.go b/common/util/utils_test.go
@@ -18,11 +18,14 @@ package util
 
 import (
 	"bytes"
+	"fmt"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/op/go-logging"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestComputeSHA256(t *testing.T) {
@@ -191,3 +194,45 @@ func TestMetadataSignatureBytesNil(t *testing.T) {
 		t.Errorf("Did not concatenate bytes correctly, expected %s, got %s", expected, result)
 	}
 }
+
+type A struct {
+	s string
+}
+
+type B struct {
+	A A
+	i int
+	X string
+}
+
+type C struct{}
+
+type D struct {
+	B B
+	c *C
+}
+
+func (a A) String() string {
+	return fmt.Sprintf("I'm '%s'", a.s)
+}
+
+func TestFlattenStruct(t *testing.T) {
+	d := &D{
+		B: B{
+			A: A{
+				s: "foo",
+			},
+			i: 42,
+			X: "bar ",
+		},
+		c: nil,
+	}
+
+	var x []string
+	flatten("", &x, reflect.ValueOf(d))
+	assert.Equal(t, 4, len(x), "expect 3 items")
+	assert.Equal(t, x[0], "B.A = I'm 'foo'")
+	assert.Equal(t, x[1], "B.i = 42")
+	assert.Equal(t, x[2], "B.X = \"bar \"")
+	assert.Equal(t, x[3], "c =")
+}
diff --git a/orderer/common/server/main.go b/orderer/common/server/main.go
@@ -7,6 +7,7 @@ SPDX-License-Identifier: Apache-2.0
 package server
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"net"
@@ -35,6 +36,7 @@ import (
 	"github.com/hyperledger/fabric/protos/utils"
 
 	"github.com/hyperledger/fabric/common/localmsp"
+	"github.com/hyperledger/fabric/common/util"
 	mspmgmt "github.com/hyperledger/fabric/msp/mgmt"
 	"github.com/hyperledger/fabric/orderer/common/performance"
 	"github.com/op/go-logging"
@@ -72,6 +74,7 @@ func Main() {
 	initializeLoggingLevel(conf)
 	initializeLocalMsp(conf)
 
+	prettyPrintStruct(conf)
 	Start(fullCmd, conf)
 }
 
@@ -341,3 +344,13 @@ func updateTrustedRoots(srv comm.GRPCServer, rootCASupport *comm.CASupport,
 		}
 	}
 }
+
+func prettyPrintStruct(i interface{}) {
+	params := util.Flatten(i)
+	var buffer bytes.Buffer
+	for i := range params {
+		buffer.WriteString("\n\t")
+		buffer.WriteString(params[i])
+	}
+	logger.Infof("Orderer config values:%s\n", buffer.String())
+}