Add cmd/yaml-patch

Author: Kris Hicks

cmd/yaml-patch/file_flag.go

@@ -0,0 +1,35 @@
+package main
+
+// Thanks, Concourse!
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type FileFlag string
+
+func (f *FileFlag) UnmarshalFlag(value string) error {
+	stat, err := os.Stat(value)
+	if err != nil {
+		return err
+	}
+
+	if stat.IsDir() {
+		return fmt.Errorf("path '%s' is a directory, not a file", value)
+	}
+
+	abs, err := filepath.Abs(value)
+	if err != nil {
+		return err
+	}
+
+	*f = FileFlag(abs)
+
+	return nil
+}
+
+func (f FileFlag) Path() string {
+	return string(f)
+}

cmd/yaml-patch/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	flags "github.com/jessevdk/go-flags"
+	yamlpatch "github.com/krishicks/yaml-patch"
+)
+
+type Opts struct {
+	OpsFiles []FileFlag `long:"ops-file" short:"o" value-name:"PATH" description:"Path to file with one or more operations"`
+}
+
+func main() {
+	var opts Opts
+	_, err := flags.Parse(&opts)
+	if err != nil {
+		log.Fatalf("error: %s\n", err)
+	}
+
+	var patches []yamlpatch.Patch
+	for _, opsFile := range opts.OpsFiles {
+		bs, err := ioutil.ReadFile(opsFile.Path())
+		if err != nil {
+			log.Fatalf("error reading opsfile: %s", err)
+		}
+		patch, err := yamlpatch.DecodePatch(bs)
+		if err != nil {
+			log.Fatalf("error decoding opsfile: %s", err)
+		}
+		patches = append(patches, patch)
+	}
+
+	doc, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		log.Fatalf("error reading from stdin: %s", err)
+	}
+
+	mdoc := doc
+	for _, patch := range patches {
+		mdoc, err = patch.Apply(mdoc)
+		if err != nil {
+			log.Fatalf("error applying patch: %s", err)
+		}
+	}
+
+	fmt.Printf("%s", mdoc)
+}

cmd/yaml-patch/main_suite_test.go

@@ -0,0 +1,18 @@
+package main_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
+
+	"testing"
+)
+
+var _ = AfterSuite(func() {
+	gexec.CleanupBuildArtifacts()
+})
+
+func TestMain(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Main Suite")
+}

cmd/yaml-patch/main_test.go

@@ -0,0 +1,14 @@
+package main_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("yaml-patch", func() {
+	It("builds", func() {
+		_, err := gexec.Build("github.com/krishicks/yaml-patch/cmd/yaml-patch")
+		Expect(err).NotTo(HaveOccurred())
+	})
+})