Removing dependencies from pkg into Docker internal code

Closes #10922

Signed-off-by: Srini Brahmaroutu <srbrahma@us.ibm.com>

common/randomid.go

@@ -0,0 +1,38 @@
+package common
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"io"
+	"strconv"
+)
+
+// TruncateID returns a shorthand version of a string identifier for convenience.
+// A collision with other shorthands is very unlikely, but possible.
+// In case of a collision a lookup with TruncIndex.Get() will fail, and the caller
+// will need to use a langer prefix, or the full-length Id.
+func TruncateID(id string) string {
+	shortLen := 12
+	if len(id) < shortLen {
+		shortLen = len(id)
+	}
+	return id[:shortLen]
+}
+
+// GenerateRandomID returns an unique id
+func GenerateRandomID() string {
+	for {
+		id := make([]byte, 32)
+		if _, err := io.ReadFull(rand.Reader, id); err != nil {
+			panic(err) // This shouldn't happen
+		}
+		value := hex.EncodeToString(id)
+		// if we try to parse the truncated for as an int and we don't have
+		// an error then the value is all numberic and causes issues when
+		// used as a hostname. ref #3869
+		if _, err := strconv.ParseInt(TruncateID(value), 10, 64); err == nil {
+			continue
+		}
+		return value
+	}
+}

truncindex/truncindex_test.go

@@ -4,7 +4,7 @@ import (
 	"math/rand"
 	"testing"
 
-	"github.com/docker/docker/utils"
+	"github.com/docker/docker/pkg/common"
 )
 
 // Test the behavior of TruncIndex, an index for querying IDs from a non-conflicting prefix.
@@ -111,7 +111,7 @@ func assertIndexGet(t *testing.T, index *TruncIndex, input, expectedResult strin
 func BenchmarkTruncIndexAdd100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -127,7 +127,7 @@ func BenchmarkTruncIndexAdd100(b *testing.B) {
 func BenchmarkTruncIndexAdd250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -143,7 +143,7 @@ func BenchmarkTruncIndexAdd250(b *testing.B) {
 func BenchmarkTruncIndexAdd500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -160,7 +160,7 @@ func BenchmarkTruncIndexGet100(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -184,7 +184,7 @@ func BenchmarkTruncIndexGet250(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -208,7 +208,7 @@ func BenchmarkTruncIndexGet500(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	index := NewTruncIndex([]string{})
 	for _, id := range testSet {
@@ -231,7 +231,7 @@ func BenchmarkTruncIndexGet500(b *testing.B) {
 func BenchmarkTruncIndexDelete100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -254,7 +254,7 @@ func BenchmarkTruncIndexDelete100(b *testing.B) {
 func BenchmarkTruncIndexDelete250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -277,7 +277,7 @@ func BenchmarkTruncIndexDelete250(b *testing.B) {
 func BenchmarkTruncIndexDelete500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -300,7 +300,7 @@ func BenchmarkTruncIndexDelete500(b *testing.B) {
 func BenchmarkTruncIndexNew100(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 100; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -311,7 +311,7 @@ func BenchmarkTruncIndexNew100(b *testing.B) {
 func BenchmarkTruncIndexNew250(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 250; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -322,7 +322,7 @@ func BenchmarkTruncIndexNew250(b *testing.B) {
 func BenchmarkTruncIndexNew500(b *testing.B) {
 	var testSet []string
 	for i := 0; i < 500; i++ {
-		testSet = append(testSet, utils.GenerateRandomID())
+		testSet = append(testSet, common.GenerateRandomID())
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -334,7 +334,7 @@ func BenchmarkTruncIndexAddGet100(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := utils.GenerateRandomID()
+		id := common.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])
@@ -359,7 +359,7 @@ func BenchmarkTruncIndexAddGet250(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := utils.GenerateRandomID()
+		id := common.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])
@@ -384,7 +384,7 @@ func BenchmarkTruncIndexAddGet500(b *testing.B) {
 	var testSet []string
 	var testKeys []string
 	for i := 0; i < 500; i++ {
-		id := utils.GenerateRandomID()
+		id := common.GenerateRandomID()
 		testSet = append(testSet, id)
 		l := rand.Intn(12) + 12
 		testKeys = append(testKeys, id[:l])