Merge pull request #3844 from dgageot/nil-empty-slides

Prefer nil empty slices (src/cmd/linuxkit)

src/cmd/linuxkit/moby/build.go

@@ -72,7 +72,7 @@ var additions = map[string]addFun{
 
 // OutputTypes returns a list of the valid output types
 func OutputTypes() []string {
-	ts := []string{}
+	var ts []string
 	for k := range streamable {
 		ts = append(ts, k)
 	}

src/cmd/linuxkit/moby/config.go

@@ -486,7 +486,7 @@ func mergeStrings(v1, v2 *[]string) *[]string {
 		return v2
 	}
 	// merge the two uniquely
-	ret := []string{}
+	var ret []string
 	m := make(map[string]bool)
 	for _, s := range *v1 {
 		if m[s] {
@@ -768,7 +768,7 @@ func ConfigToOCI(yaml *Image, config imagespec.ImageConfig, idMap map[string]uin
 			return oci, runtime, fmt.Errorf("Cannot parse tmpfs, too many ':': %s", t)
 		}
 		dest := parts[0]
-		opts := []string{}
+		var opts []string
 		if len(parts) == 2 {
 			opts = strings.Split(parts[1], ",")
 		}
@@ -830,7 +830,7 @@ func ConfigToOCI(yaml *Image, config imagespec.ImageConfig, idMap map[string]uin
 		return mountList[i].Destination < mountList[j].Destination
 	})
 
-	namespaces := []specs.LinuxNamespace{}
+	var namespaces []specs.LinuxNamespace
 
 	// net, ipc, and uts namespaces: default to not creating a new namespace (usually host namespace)
 	netNS := assignStringEmpty3("root", label.Net, yaml.Net)
@@ -914,7 +914,7 @@ func ConfigToOCI(yaml *Image, config imagespec.ImageConfig, idMap map[string]uin
 		}
 		boundingSet[capability] = true
 	}
-	bounding := []string{}
+	var bounding []string
 	for capability := range boundingSet {
 		bounding = append(bounding, capability)
 	}
@@ -922,7 +922,7 @@ func ConfigToOCI(yaml *Image, config imagespec.ImageConfig, idMap map[string]uin
 	sort.Strings(bounding)
 
 	rlimitsString := assignStrings(label.Rlimits, yaml.Rlimits)
-	rlimits := []specs.POSIXRlimit{}
+	var rlimits []specs.POSIXRlimit
 	for _, limitString := range rlimitsString {
 		rs := strings.SplitN(limitString, ",", 3)
 		var limit string
@@ -993,7 +993,7 @@ func ConfigToOCI(yaml *Image, config imagespec.ImageConfig, idMap map[string]uin
 	if err != nil {
 		return oci, runtime, err
 	}
-	additionalGroups := []uint32{}
+	var additionalGroups []uint32
 	for _, id := range agIf {
 		ag, err := idNumeric(id, idMap)
 		if err != nil {

src/cmd/linuxkit/registry/manifest.go

@@ -25,7 +25,7 @@ var platformsToSearchForIndex = []string{
 
 // PushManifest create a manifest that supports each of the provided platforms and push it out.
 func PushManifest(img string, auth dockertypes.AuthConfig) (hash string, length int, err error) {
-	srcImages := []types.ManifestEntry{}
+	var srcImages []types.ManifestEntry
 
 	for i, platform := range platformsToSearchForIndex {
 		osArchArr := strings.Split(platform, "/")

src/cmd/linuxkit/run_packet.go

@@ -152,7 +152,7 @@ func runPacket(args []string) {
 	}
 
 	client := packngo.NewClient("", apiKey, nil)
-	tags := []string{}
+	var tags []string
 
 	var dev *packngo.Device
 	var err error

src/cmd/linuxkit/run_qemu.go

@@ -624,7 +624,7 @@ func buildQemuForwardings(publishFlags multipleFlag) (string, error) {
 }
 
 func buildDockerForwardings(publishedPorts []string) ([]string, error) {
-	pmap := []string{}
+	var pmap []string
 	for _, port := range publishedPorts {
 		s, err := NewPublishedPort(port)
 		if err != nil {

src/cmd/linuxkit/scaleway.go

@@ -46,8 +46,7 @@ type ScalewayClient struct {
 func NewScalewayClient(accessKey, secretKey, zone, organizationID string) (*ScalewayClient, error) {
 	log.Debugf("Connecting to Scaleway")
 
-	scwOptions := []scw.ClientOption{}
-
+	var scwOptions []scw.ClientOption
 	if accessKey == "" || secretKey == "" {
 		config, err := scw.LoadConfig()
 		if err != nil {

src/cmd/linuxkit/util.go

@@ -141,7 +141,7 @@ func (f *flagOverEnvVarOverDefaultString) Set(value string) error {
 
 // Convert a multi-line string into an array of strings
 func splitLines(in string) []string {
-	res := []string{}
+	var res []string
 
 	s := bufio.NewScanner(strings.NewReader(in))
 	for s.Scan() {