introduce linuxkit pkg collect

Signed-off-by: Robin Winkelewski <w9ncontact@gmail.com>

src/cmd/linuxkit/pkg.go

@@ -13,6 +13,7 @@ func pkgUsage() {
 
 	fmt.Printf("'subcommand' is one of:\n")
 	fmt.Printf("  build\n")
+	fmt.Printf("  collect\n")
 	fmt.Printf("  push\n")
 	fmt.Printf("  show-tag\n")
 	fmt.Printf("\n")
@@ -52,6 +53,8 @@ func pkg(args []string) {
 	switch args[0] {
 	case "build":
 		pkgBuild(args[1:])
+	case "collect":
+		pkgCollect(args[1:])
 	case "push":
 		pkgPush(args[1:])
 	case "show-tag":

src/cmd/linuxkit/pkg_collect.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/linuxkit/linuxkit/src/cmd/linuxkit/pkglib"
+	log "github.com/sirupsen/logrus"
+)
+
+func pkgCollect(args []string) {
+	flags := flag.NewFlagSet("pkg collect", flag.ExitOnError)
+	flags.Usage = func() {
+		invoked := filepath.Base(os.Args[0])
+		fmt.Fprintf(os.Stderr, "USAGE: %s pkg collect [options] <file>[.yml]\n", invoked)
+		fmt.Fprintf(os.Stderr, "\n")
+		flags.PrintDefaults()
+	}
+
+	buildPkg := flags.String("pkgroot", "", "path to pkg source of moby config")
+	if err := flags.Parse(args); err != nil {
+		log.Fatal("Unable to parse args")
+	}
+
+	remArgs := flags.Args()
+
+	if len(remArgs) == 0 {
+		fmt.Println("Please specify a moby configuration file")
+		flags.Usage()
+		os.Exit(1)
+	}
+	m := GetMoby(remArgs)
+
+	if info, err := os.Stat(*buildPkg); err == nil && info.IsDir() {
+		err := pkglib.Collect(m, *buildPkg)
+		if err != nil {
+			log.Fatalln(err.Error())
+		}
+
+	} else {
+		log.Fatalf("Pkg dir is not valid: %v", err)
+	}
+
+}

src/cmd/linuxkit/pkglib/collect.go

@@ -0,0 +1,151 @@
+package pkglib
+
+import (
+	"crypto/sha1"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	moby "github.com/moby/tool/src/moby"
+
+	yaml "gopkg.in/yaml.v2"
+)
+
+const pkgFile = "build.yml"
+
+type imageInfo struct {
+	repo, name, tag string
+	value           *string
+}
+
+//Collect searches for placeHolder in configs image label and replaces it with its package hash if found in pkgDir. If none pkg is found it errors
+func Collect(m moby.Moby, pkgDir string) error {
+
+	imageTemplates := getImageTemplates(m)
+
+	err := walkDir(pkgDir, imageTemplates)
+	if err != nil {
+		return err
+	}
+
+	bytes, err := yaml.Marshal(&m)
+	if err != nil {
+		return err
+	}
+
+	h := sha1.New()
+	h.Write(bytes)
+	if err != nil {
+		return err
+	}
+	filename := fmt.Sprintf("%x.yml", h.Sum(nil))
+
+	err = ioutil.WriteFile(filename, bytes, 0644)
+	if err != nil {
+		return err
+	}
+	fmt.Println("created " + filename)
+	return nil
+}
+
+//this should not go deeper into a dir when build.yml is found.
+func walkDir(pkgDir string, imageTemplates []imageInfo) error {
+	err := filepath.Walk(pkgDir, func(path string, f os.FileInfo, err error) error {
+		if f.Name() == pkgFile {
+
+			b, err := ioutil.ReadFile(path)
+			if err != nil {
+				return err
+			}
+			pi := pkgInfo{}
+			if err := yaml.Unmarshal(b, &pi); err != nil {
+				return err
+			}
+
+			if pi.Image == "" {
+				return fmt.Errorf("Image field is required")
+			}
+			for i := len(imageTemplates) - 1; i >= 0; i-- {
+				if imageTemplates[i].name == pi.Image {
+					err = substitute(imageTemplates[i], path, pi)
+					if err != nil {
+						return err
+					}
+					imageTemplates = append(imageTemplates[:i], imageTemplates[i+1:]...)
+				}
+			}
+		}
+		return err
+	})
+	if err != nil {
+		return err
+	}
+
+	var errs []string
+	for _, imageString := range imageTemplates {
+		errs = append(errs, fmt.Sprintln("could not find pkg for:", *imageString.value))
+	}
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, ""))
+	}
+	return nil
+}
+
+func substitute(imageString imageInfo, path string, pi pkgInfo) error {
+	path = filepath.Dir(path)
+	git, err := newGit(path)
+	if err != nil {
+		return err
+	}
+	commit, err := git.commitHash("HEAD")
+	if err != nil {
+		return err
+	}
+
+	treeHash, err := git.treeHash(path, commit)
+	if err != nil {
+		return err
+	}
+
+	old := *imageString.value
+	*imageString.value = fmt.Sprintf("%v/%v:%v", imageString.repo, imageString.name, treeHash)
+	fmt.Println("template: " + old)
+	fmt.Println("  hashed: " + *imageString.value)
+	return nil
+}
+
+func getImageTemplates(m moby.Moby) []imageInfo {
+	var images []*moby.Image
+	var imageStrings []*string
+	var tagTemplates []imageInfo
+
+	images = append(images, m.Onboot...)
+	images = append(images, m.Services...)
+	images = append(images, m.Onshutdown...)
+
+	for _, v := range images {
+		imageStrings = append(imageStrings, &v.Image)
+	}
+	for i := range m.Init {
+		imageStrings = append(imageStrings, &m.Init[i])
+	}
+
+	for _, imageString := range imageStrings {
+		tagSplit := strings.Split(*imageString, ":")
+		tag := tagSplit[len(tagSplit)-1]
+		if isTagTemplate(tag) {
+			imageSplit := strings.Split(tagSplit[0], "/")
+			name := imageSplit[1]
+			repo := imageSplit[0]
+			tagTemplates = append(tagTemplates, imageInfo{tag: tag, name: name, repo: repo, value: imageString})
+		}
+	}
+	return tagTemplates
+}
+
+func isTagTemplate(tag string) bool {
+	return tag[:1] == "<" && tag[len(tag)-1:] == ">"
+}