Improve error handling in kyaml libraries

cmd/kyaml/cmd/cat.go

@@ -126,5 +126,5 @@ func (r *CatRunner) runE(c *cobra.Command, args []string) error {
 		Style:                 yaml.GetStyle(r.Styles...),
 	})
 
-	return kio.Pipeline{Inputs: inputs, Filters: fltr, Outputs: outputs}.Execute()
+	return handleError(c, kio.Pipeline{Inputs: inputs, Filters: fltr, Outputs: outputs}.Execute())
 }

cmd/kyaml/cmd/count.go

@@ -85,8 +85,8 @@ func (r *CountRunner) runE(c *cobra.Command, args []string) error {
 			return nil
 		}))
 	}
-	return kio.Pipeline{
+	return handleError(c, kio.Pipeline{
 		Inputs:  inputs,
 		Outputs: out,
-	}.Execute()
+	}.Execute())
 }

cmd/kyaml/cmd/fmt.go

@@ -107,8 +107,8 @@ func (r *FmtRunner) runE(c *cobra.Command, args []string) error {
 			Writer:                c.OutOrStdout(),
 			KeepReaderAnnotations: r.KeepAnnotations,
 		}
-		return kio.Pipeline{
-			Inputs: []kio.Reader{rw}, Filters: f, Outputs: []kio.Writer{rw}}.Execute()
+		return handleError(c, kio.Pipeline{
+			Inputs: []kio.Reader{rw}, Filters: f, Outputs: []kio.Writer{rw}}.Execute())
 	}
 
 	for i := range args {
@@ -120,7 +120,7 @@ func (r *FmtRunner) runE(c *cobra.Command, args []string) error {
 		err := kio.Pipeline{
 			Inputs: []kio.Reader{rw}, Filters: f, Outputs: []kio.Writer{rw}}.Execute()
 		if err != nil {
-			return err
+			return handleError(c, err)
 		}
 	}
 	return nil

cmd/kyaml/cmd/grep.go

@@ -8,9 +8,9 @@ import (
 	"strings"
 
 	"github.com/spf13/cobra"
-	"sigs.k8s.io/kustomize/pseudo/k8s/apimachinery/pkg/api/resource"
 	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/kustomize/kyaml/kio/filters"
+	"sigs.k8s.io/kustomize/pseudo/k8s/apimachinery/pkg/api/resource"
 )
 
 // Cmd returns a command GrepRunner.
@@ -133,12 +133,12 @@ func (r *GrepRunner) runE(c *cobra.Command, args []string) error {
 		inputs = append(inputs, &kio.ByteReader{Reader: c.InOrStdin()})
 	}
 
-	return kio.Pipeline{
+	return handleError(c, kio.Pipeline{
 		Inputs:  inputs,
 		Filters: filters,
 		Outputs: []kio.Writer{kio.ByteWriter{
 			Writer:                c.OutOrStdout(),
 			KeepReaderAnnotations: r.KeepAnnotations,
 		}},
-	}.Execute()
+	}.Execute())
 }

cmd/kyaml/cmd/merge.go

@@ -76,5 +76,5 @@ func (r *MergeRunner) runE(c *cobra.Command, args []string) error {
 	}
 
 	filters := []kio.Filter{filters.MergeFilter{}, filters.FormatFilter{}}
-	return kio.Pipeline{Inputs: inputs, Filters: filters, Outputs: outputs}.Execute()
+	return handleError(c, kio.Pipeline{Inputs: inputs, Filters: filters, Outputs: outputs}.Execute())
 }

cmd/kyaml/cmd/tree.go

@@ -194,7 +194,7 @@ func (r *TreeRunner) runE(c *cobra.Command, args []string) error {
 		IncludeNonReconcilers: !r.excludeNonReconcilers,
 	}}
 
-	return kio.Pipeline{
+	return handleError(c, kio.Pipeline{
 		Inputs:  []kio.Reader{input},
 		Filters: fltrs,
 		Outputs: []kio.Writer{kio.TreeWriter{
@@ -202,7 +202,7 @@ func (r *TreeRunner) runE(c *cobra.Command, args []string) error {
 			Writer:    c.OutOrStdout(),
 			Fields:    fields,
 			Structure: kio.TreeStructure(r.structure)}},
-	}.Execute()
+	}.Execute())
 }
 
 func newField(val ...string) kio.TreeWriterField {

cmd/kyaml/cmd/util.go

@@ -5,7 +5,11 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 	"strings"
+
+	"github.com/go-errors/errors"
+	"github.com/spf13/cobra"
 )
 
 // parseFieldPath parse a flag value into a field path
@@ -34,3 +38,27 @@ func parseFieldPath(path string) ([]string, error) {
 	}
 	return newParts, nil
 }
+
+func handleError(c *cobra.Command, err error) error {
+	if err == nil {
+		return nil
+	}
+	if StackOnError {
+		if err, ok := err.(*errors.Error); ok {
+			fmt.Fprint(os.Stderr, fmt.Sprintf("%s", err.Stack()))
+		}
+	}
+
+	if ExitOnError {
+		fmt.Fprintf(c.ErrOrStderr(), "Error: %v\n", err)
+		os.Exit(1)
+	}
+	return err
+}
+
+// ExitOnError if true, will cause commands to call os.Exit instead of returning an error.
+// Used for skipping printing usage on failure.
+var ExitOnError bool
+
+// StackOnError if true, will print a stack trace on failure.
+var StackOnError bool

cmd/kyaml/go.mod

@@ -1,13 +1,17 @@
 module sigs.k8s.io/kustomize/cmd/kyaml
 
-go 1.12
+go 1.13
 
 require (
+	github.com/go-errors/errors v1.0.1
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stretchr/testify v1.4.0
 	sigs.k8s.io/kustomize/kyaml v0.0.0
-	sigs.k8s.io/kustomize/pseudo/k8s v0.0.0-20191109010559-74255f6badd9
+	sigs.k8s.io/kustomize/pseudo/k8s v0.0.0
 )
 
-replace sigs.k8s.io/kustomize/kyaml v0.0.0 => ../../kyaml
+replace (
+	sigs.k8s.io/kustomize/kyaml v0.0.0 => ../../kyaml
+	sigs.k8s.io/kustomize/pseudo/k8s v0.0.0 => ../../pseudo/k8s
+)

cmd/kyaml/go.sum

@@ -94,7 +94,6 @@ github.com/spf13/cobra v0.0.5 h1:f0B+LkLX6DtmRH1isoNA9VTtNUK9K8xYd28JNNfOv/s=
 github.com/spf13/cobra v0.0.5/go.mod h1:3K3wKZymM7VvHMDS9+Akkh4K60UwM26emMESw8tLCHU=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v0.0.0-20170130214245-9ff6c6923cff/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
@@ -143,7 +142,5 @@ k8s.io/klog v0.3.0/go.mod h1:Gq+BEi5rUBO/HRz0bTSXDUcqjScdoY3a9IHpCEIOOfk=
 k8s.io/klog v1.0.0/go.mod h1:4Bi6QPql/J/LkTDqv7R/cd3hPo4k2DG6Ptcz060Ez5I=
 k8s.io/kube-openapi v0.0.0-20191107075043-30be4d16710a/go.mod h1:1TqjTSzOxsLGIKfj0lK8EeCP7K1iUG65v09OM0/WG5E=
 k8s.io/utils v0.0.0-20191030222137-2b95a09bc58d/go.mod h1:sZAwmy6armz5eXlNoLmJcl4F1QuKu7sr+mFQ0byX7Ew=
-sigs.k8s.io/kustomize/pseudo/k8s v0.0.0-20191109010559-74255f6badd9 h1:y5HZbxpf+KDyXpXSIUaxkcDB2ot78v80aLHCJ/UiyLo=
-sigs.k8s.io/kustomize/pseudo/k8s v0.0.0-20191109010559-74255f6badd9/go.mod h1:bl/gVJgYYhJZCZdYU2BfnaKYAlqFkgbJEkpl302jEss=
 sigs.k8s.io/structured-merge-diff v0.0.0-20190525122527-15d366b2352e/go.mod h1:wWxsB5ozmmv/SG7nM11ayaAW51xMvak/t1r0CSlcokI=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=

cmd/kyaml/main.go

@@ -22,6 +22,10 @@ var root = &cobra.Command{
 }
 
 func main() {
+	root.PersistentFlags().BoolVar(&cmd.StackOnError, "stack-trace", false,
+		"print a stack-trace on failure")
+
+	cmd.ExitOnError = true
 	root.AddCommand(cmd.GrepCommand())
 	root.AddCommand(cmd.TreeCommand())
 	root.AddCommand(cmd.CatCommand())