Don't install helm charts with hooks

If a helm hook is encountered in a YAML file in a helm chart's `templates`
directory, skip it.

Fixes #700
Fixes #703
Signed-off-by: bryanl <bryanliles@gmail.com>

pkg/registry/helm.go

@@ -16,15 +16,18 @@
 package registry
 
 import (
+	"bytes"
 	"io/ioutil"
 	"net/url"
 	"path"
 	"path/filepath"
+	"strings"
 
 	"github.com/ksonnet/ksonnet/pkg/app"
 	"github.com/ksonnet/ksonnet/pkg/helm"
 	"github.com/ksonnet/ksonnet/pkg/parts"
 	"github.com/ksonnet/ksonnet/pkg/util/archive"
+	ksstrings "github.com/ksonnet/ksonnet/pkg/util/strings"
 	"github.com/pkg/errors"
 )
 
@@ -161,6 +164,11 @@ func (h *Helm) ResolveLibrary(partName string, partAlias string, version string,
 
 			name := path.Join(chart.Name, "helm", chart.Version, f.Name)
 
+			if containsHelmHook(name, b) {
+				// skip this file because it has a helm hook in it
+				return nil
+			}
+
 			return onFile(name, b)
 		}
 
@@ -242,3 +250,15 @@ func (h *Helm) SetURI(uri string) error {
 	h.spec.URI = uri
 	return nil
 }
+
+// containsHelmHook checks file contents for helm hooks. Helm hooks are denoted by
+// `helm.sh/hook`.
+func containsHelmHook(name string, b []byte) bool {
+	dir := filepath.Dir(name)
+	ext := filepath.Ext(name)
+	if strings.Contains(dir, "templates") && ksstrings.InSlice(ext, []string{".yaml", ".yml"}) {
+		return bytes.Contains(b, []byte("helm.sh/hook"))
+	}
+
+	return false
+}

pkg/registry/helm_test.go

@@ -333,6 +333,54 @@ func TestHelm_ValidateURI_invalid(t *testing.T) {
 	})
 }
 
+func Test_containsHelmHook(t *testing.T) {
+	cases := []struct {
+		name     string
+		path     string
+		b        []byte
+		expected bool
+	}{
+		{
+			name:     "contains helm hook",
+			path:     "templates/file.yaml",
+			b:        []byte(`"helm.sh/hook": test-success`),
+			expected: true,
+		},
+		{
+			name:     "doesn't contain helm hook",
+			path:     "templates/file.yaml",
+			b:        []byte(`"other": test-success`),
+			expected: false,
+		},
+		{
+			name:     "contains helm hook in directory under templates",
+			path:     "templates/nested/file.yaml",
+			b:        []byte(`"helm.sh/hook": test-success`),
+			expected: true,
+		},
+		{
+			name:     "contains helm hook in directory",
+			path:     "nested/file.yaml",
+			b:        []byte(`"helm.sh/hook": test-success`),
+			expected: false,
+		},
+		{
+			name:     "contains helm hook in directory under templates and not YAML",
+			path:     "templates/file.txt",
+			b:        []byte(`"helm.sh/hook": test-success`),
+			expected: false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := containsHelmHook(tc.path, tc.b)
+			assert.Equal(t, tc.expected, got)
+		})
+	}
+
+}
+
 type fakeHelmRepositoryClient struct {
 	entries    *helm.Repository
 	entriesErr error