Add --force flag to push command

Gopkg.toml

@@ -40,3 +40,7 @@
 [[constraint]]
   name = "k8s.io/helm"
   version = "2.6.2"
+
+[[constraint]]
+  name = "github.com/Masterminds/semver"
+  version = "1.4.0"

cmd/helms3/main.go

@@ -30,6 +30,8 @@ type Action interface {
 }
 
 func main() {
+	log.SetFlags(0)
+
 	if len(os.Args) == 5 && !isAction(os.Args[1]) {
 		cmd := proxyCmd{uri: os.Args[4]}
 		ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
@@ -55,6 +57,8 @@ func main() {
 	pushTargetRepository := pushCmd.Arg("repo", "Target repository to push to").
 		Required().
 		String()
+	pushForce := pushCmd.Flag("force", "Replace the chart if it already exists. This can cause the repository to lose existing chart; use it with care").
+		Bool()
 
 	reindexCmd := cli.Command(actionReindex, "Reindex the repository.")
 	reindexTargetRepository := reindexCmd.Arg("repo", "Target repository to reindex").
@@ -94,6 +98,7 @@ func main() {
 		act = pushAction{
 			chartPath: *pushChartPath,
 			repoName:  *pushTargetRepository,
+			force:     *pushForce,
 		}
 
 	case actionReindex:
@@ -116,7 +121,12 @@ func main() {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
-	if err := act.Run(ctx); err != nil {
+	err := act.Run(ctx)
+	switch err {
+	case nil:
+	case ErrChartExists:
+		log.Fatalf("The chart already exists in the repository and cannot be overwritten without an explicit intent. If you want to replace existing chart, use --force flag:\n\n\thelm s3 push --force %s %s\n\n", *pushChartPath, *pushTargetRepository)
+	default:
 		log.Fatal(err)
 	}
 }

cmd/helms3/push.go

@@ -10,16 +10,24 @@ import (
 	"github.com/pkg/errors"
 	"k8s.io/helm/pkg/chartutil"
 	"k8s.io/helm/pkg/provenance"
+	"k8s.io/helm/pkg/repo"
 
 	"github.com/hypnoglow/helm-s3/internal/awss3"
 	"github.com/hypnoglow/helm-s3/internal/awsutil"
 	"github.com/hypnoglow/helm-s3/internal/helmutil"
 	"github.com/hypnoglow/helm-s3/internal/index"
 )
 
+var (
+	// ErrChartExists signals that chart already exists in the repository
+	// and cannot be pushed without --force flag.
+	ErrChartExists = errors.New("chart already exists")
+)
+
 type pushAction struct {
 	chartPath string
 	repoName  string
+	force     bool
 }
 
 func (act pushAction) Run(ctx context.Context) error {
@@ -54,6 +62,13 @@ func (act pushAction) Run(ctx context.Context) error {
 		return err
 	}
 
+	if cachedIndex, err := repo.LoadIndexFile(repoEntry.Cache); err == nil {
+		// if cached index exists, check if the same chart version exists in it.
+		if cachedIndex.Has(chart.Metadata.Name, chart.Metadata.Version) && !act.force {
+			return ErrChartExists
+		}
+	}
+
 	hash, err := provenance.DigestFile(fname)
 	if err != nil {
 		return errors.WithMessage(err, "get chart digest")
@@ -69,6 +84,15 @@ func (act pushAction) Run(ctx context.Context) error {
 		return errors.Wrap(err, "encode chart metadata to json")
 	}
 
+	exists, err := storage.Exists(ctx, repoEntry.URL+"/"+fname)
+	if err != nil {
+		return errors.WithMessage(err, "check if chart already exists in the repository")
+	}
+
+	if exists && !act.force {
+		return ErrChartExists
+	}
+
 	if _, err := storage.PutChart(ctx, repoEntry.URL+"/"+fname, fchart, string(serializedChartMeta), hash); err != nil {
 		return errors.WithMessage(err, "upload chart to s3")
 	}
@@ -89,7 +113,9 @@ func (act pushAction) Run(ctx context.Context) error {
 		return errors.WithMessage(err, "load index from downloaded file")
 	}
 
-	idx.Add(chart.GetMetadata(), fname, repoEntry.URL, hash)
+	if err := idx.AddOrReplace(chart.GetMetadata(), fname, repoEntry.URL, hash); err != nil {
+		return errors.WithMessage(err, "add/replace chart in the index")
+	}
 	idx.SortEntries()
 
 	idxReader, err := idx.Reader()

hack/integration-tests.sh

@@ -2,6 +2,17 @@
 set -euo pipefail
 set -x
 
+#
+# Set up
+#
+
+# Prepare chart to play with.
+helm fetch stable/postgresql --version 0.8.3
+
+#
+# Test: init repo
+#
+
 helm s3 init s3://test-bucket/charts
 if [ $? -ne 0 ]; then
     echo "Failed to initialize repo"
@@ -20,8 +31,9 @@ if [ $? -ne 0 ]; then
     exit 1
 fi
 
-# Prepare chart to play with.
-helm fetch stable/postgresql --version 0.8.3
+#
+# Test: push chart
+#
 
 helm s3 push postgresql-0.8.3.tgz test-repo
 if [ $? -ne 0 ]; then
@@ -35,23 +47,44 @@ if [ $? -ne 0 ]; then
     exit 1
 fi
 
-# Update the index so we can find the uploaded chart.
-helm repo update
-
 helm search test-repo/postgres | grep -q 0.8.3
 if [ $? -ne 0 ]; then
     echo "Failed to find uploaded chart"
     exit 1
 fi
 
+#
+# Test: push the same chart again
+#
+
+set +e # next command should return non-zero status
+
+helm s3 push postgresql-0.8.3.tgz test-repo
+if [ $? -eq 0 ]; then
+    echo "The same chart must not be pushed again"
+    exit 1
+fi
+
+set -e
+
+helm s3 push --force postgresql-0.8.3.tgz test-repo
+if [ $? -ne 0 ]; then
+    echo "The same chart must be pushed again using --force"
+    exit 1
+fi
+
+#
+# Test: fetch chart
+#
+
 helm fetch test-repo/postgresql --version 0.8.3
 if [ $? -ne 0 ]; then
     echo "Failed to fetch chart from repo"
     exit 1
 fi
 
 #
-# Delete
+# Test: delete chart
 #
 
 helm s3 delete postgresql --version 0.8.3 test-repo
@@ -65,14 +98,15 @@ if mc ls -q helm-s3-minio/test-bucket/charts/postgresql-0.8.3.tgz 2>/dev/null ;
     exit 1
 fi
 
-helm repo update
-
 if helm search test-repo/postgres | grep -q 0.8.3 ; then
     echo "Failed to delete chart from index"
     exit 1
 fi
 
+#
 # Tear down
+#
+
 rm postgresql-0.8.3.tgz
 helm repo remove test-repo
 set +x

internal/awss3/storage.go

@@ -192,6 +192,28 @@ func (s *Storage) FetchRaw(ctx context.Context, uri string) ([]byte, error) {
 	return buf.Bytes(), nil
 }
 
+// Exists returns true if an object exists in the storage.
+func (s *Storage) Exists(ctx context.Context, uri string) (bool, error) {
+	bucket, key, err := parseURI(uri)
+	if err != nil {
+		return false, err
+	}
+
+	_, err = s3.New(s.session).HeadObject(&s3.HeadObjectInput{
+		Bucket: aws.String(bucket),
+		Key:    aws.String(key),
+	})
+	if err != nil {
+		// That's weird that there is no NotFound constant in aws sdk.
+		if ae, ok := err.(awserr.Error); ok && ae.Code() == "NotFound" {
+			return false, nil
+		}
+		return false, errors.Wrap(err, "head s3 object")
+	}
+
+	return true, nil
+}
+
 // PutChart puts the chart file to the storage.
 // uri must be in the form of s3 protocol: s3://bucket-name/key[...].
 func (s *Storage) PutChart(ctx context.Context, uri string, r io.Reader, chartMeta, chartDigest string) (string, error) {

internal/index/index.go

@@ -4,10 +4,14 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"path/filepath"
+	"time"
 
+	"github.com/Masterminds/semver"
 	"github.com/ghodss/yaml"
-
+	"k8s.io/helm/pkg/proto/hapi/chart"
 	"k8s.io/helm/pkg/repo"
+	"k8s.io/helm/pkg/urlutil"
 )
 
 // Index of a helm chart repository.
@@ -42,6 +46,60 @@ func (idx *Index) UnmarshalBinary(data []byte) error {
 	return nil
 }
 
+// AddOrReplace is the same as Add but replaces the version if it exists instead
+// of adding it to the list of versions.
+func (idx *Index) AddOrReplace(md *chart.Metadata, filename, baseURL, digest string) error {
+	// TODO: this looks like a workaround.
+	// Think how we can rework this in the future.
+	// Ref: https://github.com/kubernetes/helm/issues/3230
+
+	u := filename
+	if baseURL != "" {
+		var err error
+		_, file := filepath.Split(filename)
+		u, err = urlutil.URLJoin(baseURL, file)
+		if err != nil {
+			u = filepath.Join(baseURL, file)
+		}
+	}
+	cr := &repo.ChartVersion{
+		URLs:     []string{u},
+		Metadata: md,
+		Digest:   digest,
+		Created:  time.Now(),
+	}
+
+	// If no chart with such name exists in the index, just create a new
+	// list of versions.
+	entry, ok := idx.Entries[md.Name]
+	if !ok {
+		idx.Entries[md.Name] = repo.ChartVersions{cr}
+		return nil
+	}
+
+	chartSemVer, err := semver.NewVersion(md.Version)
+	if err != nil {
+		return err
+	}
+
+	// If such version exists, replace it.
+	for i, v := range entry {
+		itemSemVer, err := semver.NewVersion(v.Version)
+		if err != nil {
+			return err
+		}
+
+		if chartSemVer.Equal(itemSemVer) {
+			idx.Entries[md.Name][i] = cr
+			return nil
+		}
+	}
+
+	// Otherwise just add to the list of versions
+	idx.Entries[md.Name] = append(entry, cr)
+	return nil
+}
+
 // Delete removes chart version from index and returns deleted item.
 func (idx *Index) Delete(name, version string) (*repo.ChartVersion, error) {
 	for chartName, chartVersions := range idx.Entries {