Merge pull request #5239 from serprex/strings-cut

Replace strings.SplitN with strings.Cut

Author: openshift-merge-bot[bot]

imagebuildah/executor.go

@@ -337,13 +337,13 @@ func newExecutor(logger *logrus.Logger, logPrefix string, store storage.Store, o
 					// We have to be careful here - it's either an argument
 					// and value, or just an argument, since they can be
 					// separated by either "=" or whitespace.
-					list := strings.SplitN(arg.Value, "=", 2)
+					argName, argValue, hasValue := strings.Cut(arg.Value, "=")
 					if !foundFirstStage {
-						if len(list) > 1 {
-							globalArgs[list[0]] = list[1]
+						if hasValue {
+							globalArgs[argName] = argValue
 						}
 					}
-					delete(exec.unusedArgs, list[0])
+					delete(exec.unusedArgs, argName)
 				}
 			case "FROM":
 				foundFirstStage = true
@@ -496,12 +496,7 @@ func (b *Executor) buildStage(ctx context.Context, cleanupStages map[int]*StageE
 			var labelLine string
 			labels := append([]string{}, b.labels...)
 			for _, labelSpec := range labels {
-				label := strings.SplitN(labelSpec, "=", 2)
-				key := label[0]
-				value := ""
-				if len(label) > 1 {
-					value = label[1]
-				}
+				key, value, _ := strings.Cut(labelSpec, "=")
 				// check only for an empty key since docker allows empty values
 				if key != "" {
 					labelLine += fmt.Sprintf(" %q=%q", key, value)
@@ -523,10 +518,8 @@ func (b *Executor) buildStage(ctx context.Context, cleanupStages map[int]*StageE
 	if len(b.envs) > 0 {
 		var envLine string
 		for _, envSpec := range b.envs {
-			env := strings.SplitN(envSpec, "=", 2)
-			key := env[0]
-			if len(env) > 1 {
-				value := env[1]
+			key, value, hasValue := strings.Cut(envSpec, "=")
+			if hasValue {
 				envLine += fmt.Sprintf(" %q=%q", key, value)
 			} else {
 				return "", nil, false, fmt.Errorf("BUG: unresolved environment variable: %q", key)
@@ -844,24 +837,18 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 							mountFlags := strings.TrimPrefix(flag, "--mount=")
 							fields := strings.Split(mountFlags, ",")
 							for _, field := range fields {
-								if strings.HasPrefix(field, "from=") {
-									fromField := strings.SplitN(field, "=", 2)
-									if len(fromField) > 1 {
-										mountFrom := fromField[1]
-										// Check if this base is a stage if yes
-										// add base to current stage's dependency tree
-										// but also confirm if this is not in additional context.
-										if _, ok := b.additionalBuildContexts[mountFrom]; !ok {
-											// Treat from as a rootfs we need to preserve
-											b.rootfsMap[mountFrom] = true
-											if _, ok := dependencyMap[mountFrom]; ok {
-												// update current stage's dependency info
-												currentStageInfo := dependencyMap[stage.Name]
-												currentStageInfo.Needs = append(currentStageInfo.Needs, mountFrom)
-											}
+								if mountFrom, hasFrom := strings.CutPrefix(field, "from="); hasFrom {
+									// Check if this base is a stage if yes
+									// add base to current stage's dependency tree
+									// but also confirm if this is not in additional context.
+									if _, ok := b.additionalBuildContexts[mountFrom]; !ok {
+										// Treat from as a rootfs we need to preserve
+										b.rootfsMap[mountFrom] = true
+										if _, ok := dependencyMap[mountFrom]; ok {
+											// update current stage's dependency info
+											currentStageInfo := dependencyMap[stage.Name]
+											currentStageInfo.Needs = append(currentStageInfo.Needs, mountFrom)
 										}
-									} else {
-										return "", nil, fmt.Errorf("invalid value for field `from=`: %q", fromField[1])
 									}
 								}
 							}

imagebuildah/stage_executor.go

@@ -565,24 +565,23 @@ func (s *StageExecutor) runStageMountPoints(mountList []string) (map[string]inte
 	stageMountPoints := make(map[string]internal.StageMountDetails)
 	for _, flag := range mountList {
 		if strings.Contains(flag, "from") {
-			arr := strings.SplitN(flag, ",", 2)
-			if len(arr) < 2 {
+			tokens := strings.Split(flag, ",")
+			if len(tokens) < 2 {
 				return nil, fmt.Errorf("Invalid --mount command: %s", flag)
 			}
-			tokens := strings.Split(flag, ",")
-			for _, val := range tokens {
-				kv := strings.SplitN(val, "=", 2)
-				switch kv[0] {
+			for _, token := range tokens {
+				key, val, hasVal := strings.Cut(token, "=")
+				switch key {
 				case "from":
-					if len(kv) == 1 {
+					if !hasVal {
 						return nil, fmt.Errorf("unable to resolve argument for `from=`: bad argument")
 					}
-					if kv[1] == "" {
+					if val == "" {
 						return nil, fmt.Errorf("unable to resolve argument for `from=`: from points to an empty value")
 					}
-					from, fromErr := imagebuilder.ProcessWord(kv[1], s.stage.Builder.Arguments())
+					from, fromErr := imagebuilder.ProcessWord(val, s.stage.Builder.Arguments())
 					if fromErr != nil {
-						return nil, fmt.Errorf("unable to resolve argument %q: %w", kv[1], fromErr)
+						return nil, fmt.Errorf("unable to resolve argument %q: %w", val, fromErr)
 					}
 					// If additional buildContext contains this
 					// give priority to that and break if additional
@@ -1748,9 +1747,9 @@ func (s *StageExecutor) getBuildArgsResolvedForRun() string {
 	dockerConfig := s.stage.Builder.Config()
 
 	for _, env := range dockerConfig.Env {
-		splitv := strings.SplitN(env, "=", 2)
-		if len(splitv) == 2 {
-			configuredEnvs[splitv[0]] = splitv[1]
+		key, val, hasVal := strings.Cut(env, "=")
+		if hasVal {
+			configuredEnvs[key] = val
 		}
 	}
 
@@ -2102,8 +2101,8 @@ func (s *StageExecutor) commit(ctx context.Context, createdBy string, emptyLayer
 		s.builder.SetPort(string(p))
 	}
 	for _, envSpec := range config.Env {
-		spec := strings.SplitN(envSpec, "=", 2)
-		s.builder.SetEnv(spec[0], spec[1])
+		key, val, _ := strings.Cut(envSpec, "=")
+		s.builder.SetEnv(key, val)
 	}
 	for _, envSpec := range s.executor.unsetEnvs {
 		s.builder.UnsetEnv(envSpec)
@@ -2139,12 +2138,8 @@ func (s *StageExecutor) commit(ctx context.Context, createdBy string, emptyLayer
 		// an intermediate image, in such case we must
 		// honor layer labels if they are configured.
 		for _, labelString := range s.executor.layerLabels {
-			label := strings.SplitN(labelString, "=", 2)
-			if len(label) > 1 {
-				s.builder.SetLabel(label[0], label[1])
-			} else {
-				s.builder.SetLabel(label[0], "")
-			}
+			labelk, labelv, _ := strings.Cut(labelString, "=")
+			s.builder.SetLabel(labelk, labelv)
 		}
 	}
 	for k, v := range config.Labels {
@@ -2157,12 +2152,8 @@ func (s *StageExecutor) commit(ctx context.Context, createdBy string, emptyLayer
 		s.builder.UnsetLabel(key)
 	}
 	for _, annotationSpec := range s.executor.annotations {
-		annotation := strings.SplitN(annotationSpec, "=", 2)
-		if len(annotation) > 1 {
-			s.builder.SetAnnotation(annotation[0], annotation[1])
-		} else {
-			s.builder.SetAnnotation(annotation[0], "")
-		}
+		annotationk, annotationv, _ := strings.Cut(annotationSpec, "=")
+		s.builder.SetAnnotation(annotationk, annotationv)
 	}
 	if imageRef != nil {
 		logName := transports.ImageName(imageRef)

internal/source/add.go

@@ -26,14 +26,14 @@ func (o *AddOptions) annotations() (map[string]string, error) {
 	annotations := make(map[string]string)
 
 	for _, unparsed := range o.Annotations {
-		parsed := strings.SplitN(unparsed, "=", 2)
-		if len(parsed) != 2 {
+		key, value, hasValue := strings.Cut(unparsed, "=")
+		if !hasValue {
 			return nil, fmt.Errorf("invalid annotation %q (expected format is \"key=value\")", unparsed)
 		}
-		if _, exists := annotations[parsed[0]]; exists {
-			return nil, fmt.Errorf("annotation %q specified more than once", parsed[0])
+		if _, exists := annotations[key]; exists {
+			return nil, fmt.Errorf("annotation %q specified more than once", key)
 		}
-		annotations[parsed[0]] = parsed[1]
+		annotations[key] = value
 	}
 
 	return annotations, nil