feat: support aliases in CLI flag, env and config (#3481)

go.mod

@@ -316,7 +316,7 @@ require (
 	github.com/sirupsen/logrus v1.9.0 // indirect
 	github.com/spdx/tools-golang v0.3.1-0.20230104082527-d6f58551be3f
 	github.com/spf13/afero v1.9.2 // indirect
-	github.com/spf13/cast v1.5.0 // indirect
+	github.com/spf13/cast v1.5.0
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
 	github.com/subosito/gotenv v1.4.1 // indirect

pkg/flag/db_flags.go

@@ -26,6 +26,12 @@ var (
 		ConfigName: "db.skip-update",
 		Value:      false,
 		Usage:      "skip updating vulnerability database",
+		Aliases: []Alias{
+			{
+				Name:       "skip-update",
+				Deprecated: true, // --security-update was renamed to --skip-db-update
+			},
+		},
 	}
 	NoProgressFlag = Flag{
 		Name:       "no-progress",
@@ -84,7 +90,14 @@ func (f *DBFlagGroup) Name() string {
 }
 
 func (f *DBFlagGroup) Flags() []*Flag {
-	return []*Flag{f.Reset, f.DownloadDBOnly, f.SkipDBUpdate, f.NoProgress, f.DBRepository, f.Light}
+	return []*Flag{
+		f.Reset,
+		f.DownloadDBOnly,
+		f.SkipDBUpdate,
+		f.NoProgress,
+		f.DBRepository,
+		f.Light,
+	}
 }
 
 func (f *DBFlagGroup) ToOptions() (DBOptions, error) {

pkg/flag/kubernetes_flags.go

@@ -6,6 +6,9 @@ var (
 		ConfigName: "kubernetes.context",
 		Value:      "",
 		Usage:      "specify a context to scan",
+		Aliases: []Alias{
+			{Name: "ctx"},
+		},
 	}
 	K8sNamespaceFlag = Flag{
 		Name:       "namespace",
@@ -23,7 +26,10 @@ var (
 	ComponentsFlag = Flag{
 		Name:       "components",
 		ConfigName: "kubernetes.components",
-		Value:      []string{"workload", "infra"},
+		Value: []string{
+			"workload",
+			"infra",
+		},
 		Usage: "specify which components to scan",
 	}
 )
@@ -56,7 +62,12 @@ func (f *K8sFlagGroup) Name() string {
 }
 
 func (f *K8sFlagGroup) Flags() []*Flag {
-	return []*Flag{f.ClusterContext, f.Namespace, f.KubeConfig, f.Components}
+	return []*Flag{
+		f.ClusterContext,
+		f.Namespace,
+		f.KubeConfig,
+		f.Components,
+	}
 }
 
 func (f *K8sFlagGroup) ToOptions() K8sOptions {

pkg/flag/options.go

@@ -3,9 +3,12 @@ package flag
 import (
 	"fmt"
 	"io"
+	"os"
 	"strings"
+	"sync"
 	"time"
 
+	"github.com/spf13/cast"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
@@ -38,6 +41,15 @@ type Flag struct {
 
 	// Deprecated represents if the flag is deprecated
 	Deprecated bool
+
+	// Aliases represents aliases
+	Aliases []Alias
+}
+
+type Alias struct {
+	Name       string
+	ConfigName string
+	Deprecated bool
 }
 
 type FlagGroup interface {
@@ -142,39 +154,58 @@ func bind(cmd *cobra.Command, flag *Flag) error {
 		viper.SetDefault(flag.ConfigName, flag.Value)
 		return nil
 	}
+
+	// Bind CLI flags
 	if flag.Persistent {
 		if err := viper.BindPFlag(flag.ConfigName, cmd.PersistentFlags().Lookup(flag.Name)); err != nil {
-			return err
+			return xerrors.Errorf("bind flag error: %w", err)
 		}
 	} else {
 		if err := viper.BindPFlag(flag.ConfigName, cmd.Flags().Lookup(flag.Name)); err != nil {
-			return err
+			return xerrors.Errorf("bind flag error: %w", err)
 		}
 	}
-	// We don't use viper.AutomaticEnv, so we need to add a prefix manually here.
-	if err := viper.BindEnv(flag.ConfigName, strings.ToUpper("trivy_"+strings.ReplaceAll(flag.Name, "-", "_"))); err != nil {
+
+	// Bind environmental variable
+	if err := bindEnv(flag); err != nil {
 		return err
 	}
 
 	return nil
 }
 
+func bindEnv(flag *Flag) error {
+	// We don't use viper.AutomaticEnv, so we need to add a prefix manually here.
+	envName := strings.ToUpper("trivy_" + strings.ReplaceAll(flag.Name, "-", "_"))
+	if err := viper.BindEnv(flag.ConfigName, envName); err != nil {
+		return xerrors.Errorf("bind env error: %w", err)
+	}
+
+	// Bind env aliases
+	for _, alias := range flag.Aliases {
+		envAlias := strings.ToUpper("trivy_" + strings.ReplaceAll(alias.Name, "-", "_"))
+		if err := viper.BindEnv(flag.ConfigName, envAlias); err != nil {
+			return xerrors.Errorf("bind env error: %w", err)
+		}
+		if alias.Deprecated {
+			if _, ok := os.LookupEnv(envAlias); ok {
+				log.Logger.Warnf("'%s' is deprecated. Use '%s' instead.", envAlias, envName)
+			}
+		}
+	}
+	return nil
+}
+
 func getString(flag *Flag) string {
-	if flag == nil {
-		return ""
-	}
-	return viper.GetString(flag.ConfigName)
+	return cast.ToString(getValue(flag))
 }
 
 func getStringSlice(flag *Flag) []string {
-	if flag == nil {
-		return nil
-	}
 	// viper always returns a string for ENV
 	// https://github.com/spf13/viper/blob/419fd86e49ef061d0d33f4d1d56d5e2a480df5bb/viper.go#L545-L553
 	// and uses strings.Field to separate values (whitespace only)
 	// we need to separate env values with ','
-	v := viper.GetStringSlice(flag.ConfigName)
+	v := cast.ToStringSlice(getValue(flag))
 	switch {
 	case len(v) == 0: // no strings
 		return nil
@@ -185,24 +216,36 @@ func getStringSlice(flag *Flag) []string {
 }
 
 func getInt(flag *Flag) int {
-	if flag == nil {
-		return 0
-	}
-	return viper.GetInt(flag.ConfigName)
+	return cast.ToInt(getValue(flag))
 }
 
 func getBool(flag *Flag) bool {
-	if flag == nil {
-		return false
-	}
-	return viper.GetBool(flag.ConfigName)
+	return cast.ToBool(getValue(flag))
 }
 
 func getDuration(flag *Flag) time.Duration {
-	if flag == nil {
-		return 0
+	return cast.ToDuration(getValue(flag))
 }
-	return viper.GetDuration(flag.ConfigName)
+
+func getValue(flag *Flag) any {
+	if flag == nil {
+		return nil
+	}
+
+	// First, looks for aliases in config file (trivy.yaml).
+	// Note that viper.RegisterAlias cannot be used for this purpose.
+	var v any
+	for _, alias := range flag.Aliases {
+		if alias.ConfigName == "" {
+			continue
+		}
+		v = viper.Get(alias.ConfigName)
+		if v != nil {
+			log.Logger.Warnf("'%s' in config file is deprecated. Use '%s' instead.", alias.ConfigName, flag.ConfigName)
+			return v
+		}
+	}
+	return viper.Get(flag.ConfigName)
 }
 
 func (f *Flags) groups() []FlagGroup {
@@ -260,13 +303,17 @@ func (f *Flags) groups() []FlagGroup {
 }
 
 func (f *Flags) AddFlags(cmd *cobra.Command) {
+	aliases := make(flagAliases)
 	for _, group := range f.groups() {
 		for _, flag := range group.Flags() {
 			addFlag(cmd, flag)
+
+			// Register flag aliases
+			aliases.Add(flag)
 		}
 	}
 
-	cmd.Flags().SetNormalizeFunc(flagNameNormalize)
+	cmd.Flags().SetNormalizeFunc(aliases.NormalizeFunc())
 }
 
 func (f *Flags) Usages(cmd *cobra.Command) string {
@@ -403,20 +450,38 @@ func (f *Flags) ToOptions(appVersion string, args []string, globalFlags *GlobalF
 	return opts, nil
 }
 
-func flagNameNormalize(f *pflag.FlagSet, name string) pflag.NormalizedName {
-	switch name {
-	case "skip-update":
-		name = SkipDBUpdateFlag.Name
-	case "policy":
-		name = ConfigPolicyFlag.Name
-	case "data":
-		name = ConfigDataFlag.Name
-	case "namespaces":
-		name = PolicyNamespaceFlag.Name
-	case "ctx":
-		name = ClusterContextFlag.Name
-	case "security-checks":
-		name = ScannersFlag.Name
+type flagAlias struct {
+	formalName string
+	deprecated bool
+	once       sync.Once
+}
+
+// flagAliases have aliases for CLI flags
+type flagAliases map[string]*flagAlias
+
+func (a flagAliases) Add(flag *Flag) {
+	if flag == nil {
+		return
+	}
+	for _, alias := range flag.Aliases {
+		a[alias.Name] = &flagAlias{
+			formalName: flag.Name,
+			deprecated: alias.Deprecated,
+		}
+	}
+}
+
+func (a flagAliases) NormalizeFunc() func(*pflag.FlagSet, string) pflag.NormalizedName {
+	return func(_ *pflag.FlagSet, name string) pflag.NormalizedName {
+		if alias, ok := a[name]; ok {
+			if alias.deprecated {
+				// NormalizeFunc is called several times
+				alias.once.Do(func() {
+					log.Logger.Warnf("'--%s' is deprecated. Use '--%s' instead.", name, alias.formalName)
+				})
+			}
+			name = alias.formalName
 		}
 		return pflag.NormalizedName(name)
 	}
+}

pkg/flag/rego_flags.go

@@ -24,18 +24,27 @@ var (
 		ConfigName: "rego.policy",
 		Value:      []string{},
 		Usage:      "specify paths to the Rego policy files directory, applying config files",
+		Aliases: []Alias{
+			{Name: "policy"},
+		},
 	}
 	ConfigDataFlag = Flag{
 		Name:       "config-data",
 		ConfigName: "rego.data",
 		Value:      []string{},
 		Usage:      "specify paths from which data for the Rego policies will be recursively loaded",
+		Aliases: []Alias{
+			{Name: "data"},
+		},
 	}
 	PolicyNamespaceFlag = Flag{
 		Name:       "policy-namespaces",
 		ConfigName: "rego.namespaces",
 		Value:      []string{},
 		Usage:      "Rego namespaces",
+		Aliases: []Alias{
+			{Name: "namespaces"},
+		},
 	}
 )
 

pkg/flag/scan_flags.go

@@ -33,6 +33,13 @@ var (
 			types.VulnerabilityScanner,
 			types.SecretScanner,
 		},
+		Aliases: []Alias{
+			{
+				Name:       "security-checks",
+				ConfigName: "scan.security-checks",
+				Deprecated: true, // --security-checks was renamed to --scanners
+			},
+		},
 		Usage: "comma-separated list of what security issues to detect (vuln,config,secret,license)",
 	}
 	FilePatternsFlag = Flag{