Improve command package isolation.

pkg/commands/build/build.go

@@ -0,0 +1,166 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package build
+
+import (
+	"errors"
+	"io"
+	"log"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"sigs.k8s.io/kustomize/pkg/constants"
+	"sigs.k8s.io/kustomize/pkg/fs"
+	"sigs.k8s.io/kustomize/pkg/loader"
+	"sigs.k8s.io/kustomize/pkg/target"
+	"sigs.k8s.io/kustomize/pkg/transformerconfig"
+)
+
+type buildOptions struct {
+	kustomizationPath      string
+	outputPath             string
+	transformerconfigPaths []string
+}
+
+var examples = `
+Use the file somedir/kustomization.yaml to generate a set of api resources:
+    build somedir
+
+Use a url pointing to a remote directory/kustomization.yaml to generate a set of api resources:
+    build url
+The url should follow hashicorp/go-getter URL format described in
+https://github.com/hashicorp/go-getter#url-format
+
+url examples:
+  sigs.k8s.io/kustomize//examples/multibases?ref=v1.0.6
+  github.com/Liujingfang1/mysql
+  github.com/Liujingfang1/kustomize//examples/helloWorld?ref=repoUrl2
+
+Advanced usage:
+Use different transformer configurations by passing files to kustomize
+    build somedir -t someconfigdir
+    build somedir -t some-transformer-configfile,another-transformer-configfile
+`
+
+// NewCmdBuild creates a new build command.
+func NewCmdBuild(
+	out io.Writer, fs fs.FileSystem,
+	decoder ifc.Decoder) *cobra.Command {
+	var o buildOptions
+	var p string
+
+	cmd := &cobra.Command{
+		Use:          "build [path]",
+		Short:        "Print current configuration per contents of " + constants.KustomizationFileName,
+		Example:      examples,
+		SilenceUsage: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(args, p, fs)
+			if err != nil {
+				return err
+			}
+			return o.RunBuild(out, fs, decoder)
+		},
+	}
+	cmd.Flags().StringVarP(
+		&o.outputPath,
+		"output", "o", "",
+		"If specified, write the build output to this path.")
+	cmd.Flags().StringVarP(
+		&p,
+		"transformer-config", "t", "",
+		"If specified, use the transformer configs load from these files.")
+	return cmd
+}
+
+// Validate validates build command.
+func (o *buildOptions) Validate(args []string, p string, fs fs.FileSystem) error {
+	if len(args) > 1 {
+		return errors.New("specify one path to " + constants.KustomizationFileName)
+	}
+	if len(args) == 0 {
+		o.kustomizationPath = "./"
+		return nil
+	}
+	o.kustomizationPath = args[0]
+
+	if p == "" {
+		return nil
+	}
+
+	if fs.IsDir(p) {
+		paths, err := fs.Glob(p + "/*")
+		if err != nil {
+			return err
+		}
+		o.transformerconfigPaths = paths
+	} else {
+		o.transformerconfigPaths = strings.Split(p, ",")
+	}
+
+	return nil
+}
+
+// RunBuild runs build command.
+func (o *buildOptions) RunBuild(
+	out io.Writer, fSys fs.FileSystem,
+	decoder ifc.Decoder) error {
+	rootLoader, err := loader.NewLoader(o.kustomizationPath, "", fSys)
+	if err != nil {
+		return err
+	}
+	defer rootLoader.Cleanup()
+	kt, err := target.NewKustTarget(
+		rootLoader, fSys,
+		makeTransformerconfig(fSys, o.transformerconfigPaths),
+		decoder)
+	if err != nil {
+		return err
+	}
+	allResources, err := kt.MakeCustomizedResMap()
+	if err != nil {
+		return err
+	}
+	// Output the objects.
+	res, err := allResources.EncodeAsYaml()
+	if err != nil {
+		return err
+	}
+	if o.outputPath != "" {
+		return fSys.WriteFile(o.outputPath, res)
+	}
+	_, err = out.Write(res)
+	return err
+}
+
+// makeTransformerConfig returns a complete TransformerConfig object from either files
+// or the default configs
+func makeTransformerconfig(fSys fs.FileSystem, paths []string) *transformerconfig.TransformerConfig {
+	ldr, err := loader.NewLoader(".", "", fSys)
+	if err != nil {
+		log.Fatalf("error creating loader to load transformer configurations %v\n", err)
+	}
+	if paths == nil || len(paths) == 0 {
+		return transformerconfig.MakeDefaultTransformerConfig()
+	}
+	t, err := transformerconfig.MakeTransformerConfigFromFiles(ldr, paths)
+	if err != nil {
+		log.Fatalf("failed to load transformer configrations %v\n", err)
+	}
+	return t
+}