refactor cmd/config to internal

cmd/config/internal/commands/cmdwrap.go

@@ -0,0 +1,139 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package commands
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/kio/filters"
+)
+
+// GetWrapRunner returns a command runner.
+func GetWrapRunner() *WrapRunner {
+	r := &WrapRunner{}
+	c := &cobra.Command{
+		Use:   "wrap CMD...",
+		Short: "Wrap an executable so it implements the config fn interface",
+		Long: `Wrap an executable so it implements the config fn interface
+
+wrap simplifies writing config functions by:
+
+- invoking an executable command converting an input ResourceList into environment
+- merging the output onto the original input as a set of patches
+- setting filenames on any Resources missing them
+
+config function authors may use wrap by using it to invoke a command from a container image
+
+The following are equivalent:
+
+	kyaml wrap -- CMD
+
+	kyaml xargs -- CMD | kyaml merge | kyaml fmt --set-filenames
+
+Environment Variables:
+
+  KUST_OVERRIDE_DIR:
+
+    Path to a directory containing patches to apply to after merging.
+`,
+		Example: `
+
+`,
+		RunE:               r.runE,
+		SilenceUsage:       true,
+		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
+		Args:               cobra.MinimumNArgs(1),
+	}
+	r.Command = c
+	r.XArgs = GetXArgsRunner()
+	c.Flags().BoolVar(&r.XArgs.EnvOnly,
+		"env-only", true, "only set env vars, not arguments.")
+	c.Flags().StringVar(&r.XArgs.WrapKind,
+		"wrap-kind", "List", "wrap the input xargs give to the command in this type.")
+	c.Flags().StringVar(&r.XArgs.WrapVersion,
+		"wrap-version", "v1", "wrap the input xargs give to the command in this type.")
+	return r
+}
+
+// WrapRunner contains the run function
+type WrapRunner struct {
+	Command *cobra.Command
+	XArgs   *XArgsRunner
+	getEnv  func(key string) string
+}
+
+const (
+	KustMergeEnv       = "KUST_MERGE"
+	KustOverrideDirEnv = "KUST_OVERRIDE_DIR"
+)
+
+func WrapCommand() *cobra.Command {
+	return GetWrapRunner().Command
+}
+
+func (r *WrapRunner) runE(c *cobra.Command, args []string) error {
+	if r.getEnv == nil {
+		r.getEnv = os.Getenv
+	}
+	xargsIn := &bytes.Buffer{}
+	if _, err := io.Copy(xargsIn, c.InOrStdin()); err != nil {
+		return err
+	}
+	mergeInput := bytes.NewBuffer(xargsIn.Bytes())
+	// Run the command
+	xargsOut := &bytes.Buffer{}
+	r.XArgs.Command.SetArgs(args)
+	r.XArgs.Command.SetIn(xargsIn)
+	r.XArgs.Command.SetOut(xargsOut)
+	r.XArgs.Command.SetErr(os.Stderr)
+	if err := r.XArgs.Command.Execute(); err != nil {
+		return err
+	}
+
+	// merge the results
+	buff := &kio.PackageBuffer{}
+
+	var fltrs []kio.Filter
+	var inputs []kio.Reader
+	if r.getEnv(KustMergeEnv) == "" || r.getEnv(KustMergeEnv) == "true" || r.getEnv(KustMergeEnv) == "1" {
+		inputs = append(inputs, &kio.ByteReader{Reader: mergeInput})
+		fltrs = append(fltrs, &filters.MergeFilter{})
+	}
+	inputs = append(inputs, &kio.ByteReader{Reader: xargsOut})
+
+	if err := (kio.Pipeline{Inputs: inputs, Filters: fltrs, Outputs: []kio.Writer{buff}}).
+		Execute(); err != nil {
+		return err
+	}
+
+	inputs, fltrs = []kio.Reader{buff}, nil
+	if r.getEnv(KustOverrideDirEnv) != "" {
+		// merge the overrides on top of the output
+		fltrs = append(fltrs, filters.MergeFilter{})
+		inputs = append(inputs,
+			kio.LocalPackageReader{
+				OmitReaderAnnotations: true, // don't set path annotations, as they would override
+				PackagePath:           r.getEnv(KustOverrideDirEnv)})
+	}
+	fltrs = append(fltrs,
+		&filters.FileSetter{
+			FilenamePattern: filepath.Join("config", filters.DefaultFilenamePattern)},
+		&filters.FormatFilter{})
+
+	err := kio.Pipeline{
+		Inputs:  inputs,
+		Filters: fltrs,
+		Outputs: []kio.Writer{kio.ByteWriter{
+			Sort:                  true,
+			KeepReaderAnnotations: true,
+			Writer:                c.OutOrStdout(),
+			WrappingKind:          kio.ResourceListKind,
+			WrappingAPIVersion:    kio.ResourceListAPIVersion}}}.Execute()
+	return handleError(c, err)
+}