opts: preserve case in network option values

cli/command/container/opts_test.go

@@ -609,6 +609,17 @@ func TestParseNetworkConfig(t *testing.T) {
 			expected:        map[string]*networktypes.EndpointSettings{},
 			expectedHostCfg: container.HostConfig{NetworkMode: "net1"},
 		},
+		{
+			name:  "single-network-advanced-preserves-case",
+			flags: []string{"--network", "name=MyNetwork,alias=WebApp,driver-opt=CustomKey=CaseSensitiveValue"},
+			expected: map[string]*networktypes.EndpointSettings{
+				"MyNetwork": {
+					Aliases:    []string{"WebApp"},
+					DriverOpts: map[string]string{"CustomKey": "CaseSensitiveValue"},
+				},
+			},
+			expectedHostCfg: container.HostConfig{NetworkMode: "MyNetwork"},
+		},
 		{
 			name: "single-network-legacy-with-options",
 			flags: []string{

opts/network.go

@@ -60,12 +60,12 @@ func (n *NetworkOpt) Set(value string) error { //nolint:gocyclo
 		netOpt.Aliases = []string{}
 		for _, field := range fields {
 			// TODO(thaJeztah): these options should not be case-insensitive.
-			key, val, ok := strings.Cut(strings.ToLower(field), "=")
+			key, val, ok := strings.Cut(field, "=")
 			if !ok || key == "" {
 				return fmt.Errorf("invalid field %s", field)
 			}
 
-			key = strings.TrimSpace(key)
+			key = strings.ToLower(strings.TrimSpace(key))
 			val = strings.TrimSpace(val)
 
 			switch key {
@@ -148,9 +148,7 @@ func (n *NetworkOpt) NetworkMode() string {
 }
 
 func parseDriverOpt(driverOpt string) (string, string, error) {
-	// TODO(thaJeztah): these options should not be case-insensitive.
-	// TODO(thaJeztah): should value be converted to lowercase as well, or only the key?
-	key, value, ok := strings.Cut(strings.ToLower(driverOpt), "=")
+	key, value, ok := strings.Cut(driverOpt, "=")
 	if !ok || key == "" {
 		return "", "", errors.New("invalid key value pair format in driver options")
 	}

opts/network_test.go

@@ -35,6 +35,30 @@ func TestNetworkOptAdvancedSyntax(t *testing.T) {
 		value    string
 		expected []NetworkAttachmentOpts
 	}{
+		{
+			value: "name=MyNetwork,alias=WebApp,driver-opt=CustomKey=CaseSensitiveValue",
+			expected: []NetworkAttachmentOpts{
+				{
+					Target:  "MyNetwork",
+					Aliases: []string{"WebApp"},
+					DriverOpts: map[string]string{
+						"CustomKey": "CaseSensitiveValue",
+					},
+				},
+			},
+		},
+		{
+			value: "NAME=MyNetwork,ALIAS=WebApp,DRIVER-OPT=CustomKey=CaseSensitiveValue",
+			expected: []NetworkAttachmentOpts{
+				{
+					Target:  "MyNetwork",
+					Aliases: []string{"WebApp"},
+					DriverOpts: map[string]string{
+						"CustomKey": "CaseSensitiveValue",
+					},
+				},
+			},
+		},
 		{
 			value: "name=docknet1,alias=web,driver-opt=field1=value1",
 			expected: []NetworkAttachmentOpts{
@@ -107,9 +131,7 @@ func TestNetworkOptAdvancedSyntax(t *testing.T) {
 					Target:  "docknet1",
 					Aliases: []string{},
 					DriverOpts: map[string]string{
-						// The CLI converts IFNAME to ifname - it probably shouldn't, but the API
-						// allows ifname to cater for this.
-						"com.docker.network.endpoint.sysctls": "net.ipv6.conf.ifname.accept_ra=2,net.ipv6.conf.ifname.forwarding=1",
+						"com.docker.network.endpoint.sysctls": "net.ipv6.conf.IFNAME.accept_ra=2,net.ipv6.conf.IFNAME.forwarding=1",
 					},
 				},
 			},