fixes #2817 container run with the empty label

apis/opts/labels.go

@@ -1,28 +1,25 @@
 package opts
 
 import (
-	"fmt"
 	"strings"
 )
 
 // ParseLabels parses the labels params of container.
-func ParseLabels(labels []string) (map[string]string, error) {
+func ParseLabels(labels []string) map[string]string {
 	results := make(map[string]string)
 	for _, label := range labels {
-		fields, err := parseLabel(label)
-		if err != nil {
-			return nil, err
-		}
+		fields := parseLabel(label)
 		k, v := fields[0], fields[1]
 		results[k] = v
 	}
-	return results, nil
+	return results
 }
 
-func parseLabel(label string) ([]string, error) {
+func parseLabel(label string) []string {
 	fields := strings.SplitN(label, "=", 2)
-	if len(fields) != 2 {
-		return nil, fmt.Errorf("invalid label %s: label must be in format of key=value", label)
+	// Only input key without value
+	if len(fields) == 1 {
+		fields = append(fields, "")
 	}
-	return fields, nil
+	return fields
 }

apis/opts/labels_test.go

@@ -1,7 +1,6 @@
 package opts
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -10,8 +9,8 @@ import (
 func TestParseLabels(t *testing.T) {
 	type result struct {
 		labels map[string]string
-		err    error
 	}
+
 	type TestCase struct {
 		input    []string
 		expected result
@@ -24,7 +23,6 @@ func TestParseLabels(t *testing.T) {
 				labels: map[string]string{
 					"a": "b",
 				},
-				err: nil,
 			},
 		},
 		{
@@ -33,7 +31,6 @@ func TestParseLabels(t *testing.T) {
 				labels: map[string]string{
 					"a": "b",
 				},
-				err: nil,
 			},
 		},
 		{
@@ -43,21 +40,49 @@ func TestParseLabels(t *testing.T) {
 				labels: map[string]string{
 					"a": "bb",
 				},
-				err: nil,
+			},
+		},
+		// only input key
+		{
+			input: []string{"a"},
+			expected: result{
+				labels: map[string]string{
+					"a": "",
+				},
+			},
+		},
+		{
+			input: []string{"a="},
+			expected: result{
+				labels: map[string]string{
+					"a": "",
+				},
+			},
+		},
+		{
+			input: []string{"a=b=c"},
+			expected: result{
+				labels: map[string]string{
+					"a": "b=c",
+				},
+			},
+		},
+		{
+			input: []string{},
+			expected: result{
+				labels: map[string]string{},
 			},
 		},
 		{
-			input: []string{"ThisIsALableWithoutEqualMark"},
+			input: nil,
 			expected: result{
-				labels: nil,
-				err:    fmt.Errorf("invalid label ThisIsALableWithoutEqualMark: label must be in format of key=value"),
+				labels: map[string]string{},
 			},
 		},
 	}
 
 	for _, testCase := range testCases {
-		labels, err := ParseLabels(testCase.input)
-		assert.Equal(t, testCase.expected.err, err)
+		labels := ParseLabels(testCase.input)
 		assert.Equal(t, testCase.expected.labels, labels)
 	}
 }

cli/container.go

@@ -97,10 +97,7 @@ type container struct {
 }
 
 func (c *container) config() (*types.ContainerCreateConfig, error) {
-	labels, err := opts.ParseLabels(c.labels)
-	if err != nil {
-		return nil, err
-	}
+	labels := opts.ParseLabels(c.labels)
 
 	memory, err := opts.ParseMemory(c.memory)
 	if err != nil {

daemon/mgr/container.go

@@ -1149,10 +1149,7 @@ func (mgr *ContainerManager) Update(ctx context.Context, name string, config *ty
 	// but ContainerConfig.Labels is map[string]string
 	if len(config.Label) != 0 {
 		// support remove some labels
-		newLabels, err := opts.ParseLabels(config.Label)
-		if err != nil {
-			return errors.Wrapf(err, "failed to parse labels")
-		}
+		newLabels := opts.ParseLabels(config.Label)
 
 		for k, v := range newLabels {
 			if v == "" {