Duplicate plugin entries in Helm

@@ -37,7 +37,7 @@ func TestLocalInstaller(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	source := "../testdata/plugdir/echo"
+	source := "../testdata/plugdir/good/echo"
 	i, err := NewForSource(source, "")
 	if err != nil {
 		t.Fatalf("unexpected error: %s", err)

@@ -56,7 +56,7 @@ func TestVCSInstaller(t *testing.T) {
 	}
 
 	source := "https://github.com/adamreese/helm-env"
-	testRepoPath, _ := filepath.Abs("../testdata/plugdir/echo")
+	testRepoPath, _ := filepath.Abs("../testdata/plugdir/good/echo")
 	repo := &testRepo{
 		local: testRepoPath,
 		tags:  []string{"0.1.0", "0.1.1"},

@@ -96,6 +96,12 @@ type Metadata struct {
 	// Downloaders field is used if the plugin supply downloader mechanism
 	// for special protocols.
 	Downloaders []Downloaders `json:"downloaders"`
+
+	// UseTunnelDeprecated indicates that this command needs a tunnel.
+	// Setting this will cause a number of side effects, such as the
+	// automatic setting of HELM_HOST.
+	// DEPRECATED and unused, but retained for backwards compatibility with Helm 2 plugins. Remove in Helm 4
+	UseTunnelDeprecated bool `json:"useTunnel,omitempty"`
 }
 
 // Plugin represents a plugin.
@@ -200,7 +206,7 @@ func LoadDir(dirname string) (*Plugin, error) {
 	}
 
 	plug := &Plugin{Dir: dirname}
-	if err := yaml.Unmarshal(data, &plug.Metadata); err != nil {
+	if err := yaml.UnmarshalStrict(data, &plug.Metadata); err != nil {
 		return nil, errors.Wrapf(err, "failed to load plugin at %q", pluginfile)
 	}
 	return plug, validatePluginData(plug, pluginfile)

@@ -178,7 +178,7 @@ func TestNoMatchPrepareCommand(t *testing.T) {
 }
 
 func TestLoadDir(t *testing.T) {
-	dirname := "testdata/plugdir/hello"
+	dirname := "testdata/plugdir/good/hello"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -205,8 +205,15 @@ func TestLoadDir(t *testing.T) {
 	}
 }
 
+func TestLoadDirDuplicateEntries(t *testing.T) {
+	dirname := "testdata/plugdir/bad/duplicate-entries"
+	if _, err := LoadDir(dirname); err == nil {
+		t.Errorf("successfully loaded plugin with duplicate entries when it should've failed")
+	}
+}
+
 func TestDownloader(t *testing.T) {
-	dirname := "testdata/plugdir/downloader"
+	dirname := "testdata/plugdir/good/downloader"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -244,7 +251,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("expected empty dir to have 0 plugins")
 	}
 
-	basedir := "testdata/plugdir"
+	basedir := "testdata/plugdir/good"
 	plugs, err := LoadAll(basedir)
 	if err != nil {
 		t.Fatalf("Could not load %q: %s", basedir, err)
@@ -288,7 +295,7 @@ func TestFindPlugins(t *testing.T) {
 		},
 		{
 			name:     "normal",
-			plugdirs: "./testdata/plugdir",
+			plugdirs: "./testdata/plugdir/good",
 			expected: 3,
 		},
 	}

@@ -0,0 +1,11 @@
+name: "duplicate-entries"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "echo hello"
+ignoreFlags: true
+hooks:
+  install: "echo installing..."
+hooks:
+  install: "echo installing something different"

@@ -5,6 +5,5 @@ description: |-
   description
 command: "$HELM_PLUGIN_SELF/hello.sh"
 ignoreFlags: true
-install: "echo installing..."
 hooks:
   install: "echo installing..."

@@ -48,7 +48,7 @@ func TestLocalInstaller(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	source := "../testdata/plugdir/echo"
+	source := "../testdata/plugdir/good/echo"
 	i, err := NewForSource(source, "", home)
 	if err != nil {
 		t.Errorf("unexpected error: %s", err)

@@ -61,7 +61,7 @@ func TestVCSInstaller(t *testing.T) {
 	}
 
 	source := "https://github.com/adamreese/helm-env"
-	testRepoPath, _ := filepath.Abs("../testdata/plugdir/echo")
+	testRepoPath, _ := filepath.Abs("../testdata/plugdir/good/echo")
 	repo := &testRepo{
 		local: testRepoPath,
 		tags:  []string{"0.1.0", "0.1.1"},

@@ -22,9 +22,10 @@ import (
 	"path/filepath"
 	"strings"
 
-	helm_env "k8s.io/helm/pkg/helm/environment"
-
 	"github.com/ghodss/yaml"
+	yaml2 "gopkg.in/yaml.v2"
+
+	helm_env "k8s.io/helm/pkg/helm/environment"
 )
 
 const pluginFileName = "plugin.yaml"
@@ -120,12 +121,20 @@ func LoadDir(dirname string) (*Plugin, error) {
 	}
 
 	plug := &Plugin{Dir: dirname}
+	if err := validateMeta(data); err != nil {
+		return nil, err
+	}
 	if err := yaml.Unmarshal(data, &plug.Metadata); err != nil {
 		return nil, err
 	}
 	return plug, nil
 }
 
+func validateMeta(data []byte) error {
+	// This is done ONLY for validation. We need to use ghodss/yaml for the actual parsing.
+	return yaml2.UnmarshalStrict(data, &Metadata{})
+}
+
 // LoadAll loads all plugins found beneath the base directory.
 //
 // This scans only one directory level.

@@ -64,7 +64,7 @@ func TestPrepareCommand(t *testing.T) {
 }
 
 func TestLoadDir(t *testing.T) {
-	dirname := "testdata/plugdir/hello"
+	dirname := "testdata/plugdir/good/hello"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -92,8 +92,15 @@ func TestLoadDir(t *testing.T) {
 	}
 }
 
+func TestLoadDirDuplicateEntries(t *testing.T) {
+	dirname := "testdata/plugdir/bad/duplicate-entries"
+	if _, err := LoadDir(dirname); err == nil {
+		t.Errorf("successfully loaded plugin with duplicate entries when it should've failed")
+	}
+}
+
 func TestDownloader(t *testing.T) {
-	dirname := "testdata/plugdir/downloader"
+	dirname := "testdata/plugdir/good/downloader"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -131,7 +138,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("expected empty dir to have 0 plugins")
 	}
 
-	basedir := "testdata/plugdir"
+	basedir := "testdata/plugdir/good"
 	plugs, err := LoadAll(basedir)
 	if err != nil {
 		t.Fatalf("Could not load %q: %s", basedir, err)

@@ -0,0 +1,12 @@
+name: "duplicate-entries"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "echo hello"
+useTunnel: true
+ignoreFlags: true
+hooks:
+  install: "echo installing..."
+hooks:
+  install: "echo installing something different"

@@ -6,6 +6,5 @@ description: |-
 command: "$HELM_PLUGIN_SELF/hello.sh"
 useTunnel: true
 ignoreFlags: true
-install: "echo installing..."
 hooks:
   install: "echo installing..."

@@ -48,7 +48,7 @@ func TestLocalInstaller(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	source := "../testdata/plugdir/echo"
+	source := "../testdata/plugdir/good/echo"
 	i, err := NewForSource(source, "", home)
 	if err != nil {
 		t.Errorf("unexpected error: %s", err)

@@ -61,7 +61,7 @@ func TestVCSInstaller(t *testing.T) {
 	}
 
 	source := "https://github.com/adamreese/helm-env"
-	testRepoPath, _ := filepath.Abs("../testdata/plugdir/echo")
+	testRepoPath, _ := filepath.Abs("../testdata/plugdir/good/echo")
 	repo := &testRepo{
 		local: testRepoPath,
 		tags:  []string{"0.1.0", "0.1.1"},

@@ -21,9 +21,10 @@ import (
 	"path/filepath"
 	"strings"
 
-	helm_env "k8s.io/helm/pkg/helm/environment"
-
 	"github.com/ghodss/yaml"
+	yaml2 "gopkg.in/yaml.v2"
+
+	helm_env "k8s.io/helm/pkg/helm/environment"
 )
 
 const pluginFileName = "plugin.yaml"
@@ -119,12 +120,20 @@ func LoadDir(dirname string) (*Plugin, error) {
 	}
 
 	plug := &Plugin{Dir: dirname}
+	if err := validateMeta(data); err != nil {
+		return nil, err
+	}
 	if err := yaml.Unmarshal(data, &plug.Metadata); err != nil {
 		return nil, err
 	}
 	return plug, nil
 }
 
+func validateMeta(data []byte) error {
+	// This is done ONLY for validation. We need to use ghodss/yaml for the actual parsing.
+	return yaml2.UnmarshalStrict(data, &Metadata{})
+}
+
 // LoadAll loads all plugins found beneath the base directory.
 //
 // This scans only one directory level.

@@ -64,7 +64,7 @@ func TestPrepareCommand(t *testing.T) {
 }
 
 func TestLoadDir(t *testing.T) {
-	dirname := "testdata/plugdir/hello"
+	dirname := "testdata/plugdir/good/hello"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -92,8 +92,15 @@ func TestLoadDir(t *testing.T) {
 	}
 }
 
+func TestLoadDirDuplicateEntries(t *testing.T) {
+	dirname := "testdata/plugdir/bad/duplicate-entries"
+	if _, err := LoadDir(dirname); err == nil {
+		t.Errorf("successfully loaded plugin with duplicate entries when it should've failed")
+	}
+}
+
 func TestDownloader(t *testing.T) {
-	dirname := "testdata/plugdir/downloader"
+	dirname := "testdata/plugdir/good/downloader"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -131,7 +138,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("expected empty dir to have 0 plugins")
 	}
 
-	basedir := "testdata/plugdir"
+	basedir := "testdata/plugdir/good"
 	plugs, err := LoadAll(basedir)
 	if err != nil {
 		t.Fatalf("Could not load %q: %s", basedir, err)

@@ -0,0 +1,12 @@
+name: "duplicate-entries"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "echo hello"
+useTunnel: true
+ignoreFlags: true
+hooks:
+  install: "echo installing..."
+hooks:
+  install: "echo installing something different"

@@ -6,6 +6,5 @@ description: |-
 command: "$HELM_PLUGIN_SELF/hello.sh"
 useTunnel: true
 ignoreFlags: true
-install: "echo installing..."
 hooks:
   install: "echo installing..."

@@ -48,7 +48,7 @@ func TestLocalInstaller(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	source := "../testdata/plugdir/echo"
+	source := "../testdata/plugdir/good/echo"
 	i, err := NewForSource(source, "", home)
 	if err != nil {
 		t.Errorf("unexpected error: %s", err)

@@ -61,7 +61,7 @@ func TestVCSInstaller(t *testing.T) {
 	}
 
 	source := "https://github.com/adamreese/helm-env"
-	testRepoPath, _ := filepath.Abs("../testdata/plugdir/echo")
+	testRepoPath, _ := filepath.Abs("../testdata/plugdir/good/echo")
 	repo := &testRepo{
 		local: testRepoPath,
 		tags:  []string{"0.1.0", "0.1.1"},

@@ -22,9 +22,10 @@ import (
 	"path/filepath"
 	"strings"
 
-	helm_env "k8s.io/helm/pkg/helm/environment"
-
 	"github.com/ghodss/yaml"
+	yaml2 "gopkg.in/yaml.v2"
+
+	helm_env "k8s.io/helm/pkg/helm/environment"
 )
 
 const pluginFileName = "plugin.yaml"
@@ -120,12 +121,20 @@ func LoadDir(dirname string) (*Plugin, error) {
 	}
 
 	plug := &Plugin{Dir: dirname}
+	if err := validateMeta(data); err != nil {
+		return nil, err
+	}
 	if err := yaml.Unmarshal(data, &plug.Metadata); err != nil {
 		return nil, err
 	}
 	return plug, nil
 }
 
+func validateMeta(data []byte) error {
+	// This is done ONLY for validation. We need to use ghodss/yaml for the actual parsing.
+	return yaml2.UnmarshalStrict(data, &Metadata{})
+}
+
 // LoadAll loads all plugins found beneath the base directory.
 //
 // This scans only one directory level.

@@ -64,7 +64,7 @@ func TestPrepareCommand(t *testing.T) {
 }
 
 func TestLoadDir(t *testing.T) {
-	dirname := "testdata/plugdir/hello"
+	dirname := "testdata/plugdir/good/hello"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -92,8 +92,15 @@ func TestLoadDir(t *testing.T) {
 	}
 }
 
+func TestLoadDirDuplicateEntries(t *testing.T) {
+	dirname := "testdata/plugdir/bad/duplicate-entries"
+	if _, err := LoadDir(dirname); err == nil {
+		t.Errorf("successfully loaded plugin with duplicate entries when it should've failed")
+	}
+}
+
 func TestDownloader(t *testing.T) {
-	dirname := "testdata/plugdir/downloader"
+	dirname := "testdata/plugdir/good/downloader"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -131,7 +138,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("expected empty dir to have 0 plugins")
 	}
 
-	basedir := "testdata/plugdir"
+	basedir := "testdata/plugdir/good"
 	plugs, err := LoadAll(basedir)
 	if err != nil {
 		t.Fatalf("Could not load %q: %s", basedir, err)

@@ -0,0 +1,12 @@
+name: "duplicate-entries"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "echo hello"
+useTunnel: true
+ignoreFlags: true
+hooks:
+  install: "echo installing..."
+hooks:
+  install: "echo installing something different"

@@ -6,6 +6,5 @@ description: |-
 command: "$HELM_PLUGIN_SELF/hello.sh"
 useTunnel: true
 ignoreFlags: true
-install: "echo installing..."
 hooks:
   install: "echo installing..."

@@ -37,7 +37,7 @@ func TestLocalInstaller(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	source := "../testdata/plugdir/echo"
+	source := "../testdata/plugdir/good/echo"
 	i, err := NewForSource(source, "")
 	if err != nil {
 		t.Fatalf("unexpected error: %s", err)

@@ -56,7 +56,7 @@ func TestVCSInstaller(t *testing.T) {
 	}
 
 	source := "https://github.com/adamreese/helm-env"
-	testRepoPath, _ := filepath.Abs("../testdata/plugdir/echo")
+	testRepoPath, _ := filepath.Abs("../testdata/plugdir/good/echo")
 	repo := &testRepo{
 		local: testRepoPath,
 		tags:  []string{"0.1.0", "0.1.1"},

@@ -96,6 +96,12 @@ type Metadata struct {
 	// Downloaders field is used if the plugin supply downloader mechanism
 	// for special protocols.
 	Downloaders []Downloaders `json:"downloaders"`
+
+	// UseTunnelDeprecated indicates that this command needs a tunnel.
+	// Setting this will cause a number of side effects, such as the
+	// automatic setting of HELM_HOST.
+	// DEPRECATED and unused, but retained for backwards compatibility with Helm 2 plugins. Remove in Helm 4
+	UseTunnelDeprecated bool `json:"useTunnel,omitempty"`
 }
 
 // Plugin represents a plugin.
@@ -200,7 +206,7 @@ func LoadDir(dirname string) (*Plugin, error) {
 	}
 
 	plug := &Plugin{Dir: dirname}
-	if err := yaml.Unmarshal(data, &plug.Metadata); err != nil {
+	if err := yaml.UnmarshalStrict(data, &plug.Metadata); err != nil {
 		return nil, errors.Wrapf(err, "failed to load plugin at %q", pluginfile)
 	}
 	return plug, validatePluginData(plug, pluginfile)

@@ -178,7 +178,7 @@ func TestNoMatchPrepareCommand(t *testing.T) {
 }
 
 func TestLoadDir(t *testing.T) {
-	dirname := "testdata/plugdir/hello"
+	dirname := "testdata/plugdir/good/hello"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -205,8 +205,15 @@ func TestLoadDir(t *testing.T) {
 	}
 }
 
+func TestLoadDirDuplicateEntries(t *testing.T) {
+	dirname := "testdata/plugdir/bad/duplicate-entries"
+	if _, err := LoadDir(dirname); err == nil {
+		t.Errorf("successfully loaded plugin with duplicate entries when it should've failed")
+	}
+}
+
 func TestDownloader(t *testing.T) {
-	dirname := "testdata/plugdir/downloader"
+	dirname := "testdata/plugdir/good/downloader"
 	plug, err := LoadDir(dirname)
 	if err != nil {
 		t.Fatalf("error loading Hello plugin: %s", err)
@@ -244,7 +251,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("expected empty dir to have 0 plugins")
 	}
 
-	basedir := "testdata/plugdir"
+	basedir := "testdata/plugdir/good"
 	plugs, err := LoadAll(basedir)
 	if err != nil {
 		t.Fatalf("Could not load %q: %s", basedir, err)
@@ -288,7 +295,7 @@ func TestFindPlugins(t *testing.T) {
 		},
 		{
 			name:     "normal",
-			plugdirs: "./testdata/plugdir",
+			plugdirs: "./testdata/plugdir/good",
 			expected: 3,
 		},
 	}

@@ -0,0 +1,11 @@
+name: "duplicate-entries"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "echo hello"
+ignoreFlags: true
+hooks:
+  install: "echo installing..."
+hooks:
+  install: "echo installing something different"

@@ -5,6 +5,5 @@ description: |-
   description
 command: "$HELM_PLUGIN_SELF/hello.sh"
 ignoreFlags: true
-install: "echo installing..."
 hooks:
   install: "echo installing..."

@@ -17,7 +17,9 @@ package chartutil
 
 import (
 	"errors"
+	"fmt"
 	"log"
+	"regexp"
 	"strings"
 	"time"
 
@@ -219,6 +221,9 @@ func ProcessRequirementsTags(reqs *Requirements, cvals Values) {
 
 }
 
+// Validate alias names against this regexp
+var aliasRegexp = regexp.MustCompile("^[a-zA-Z0-9-_]+$")
+
 func getAliasDependency(charts []*chart.Chart, aliasChart *Dependency) *chart.Chart {
 	var chartFound chart.Chart
 	for _, existingChart := range charts {
@@ -237,6 +242,11 @@ func getAliasDependency(charts []*chart.Chart, aliasChart *Dependency) *chart.Ch
 		chartFound = *existingChart
 		newMetadata := *existingChart.Metadata
 		if aliasChart.Alias != "" {
+			// Make sure Alias is well-formed
+			if !aliasRegexp.MatchString(aliasChart.Alias) {
+				fmt.Printf("Invalid alias in dependency %q. Skipping.", aliasChart.Name)
+				continue
+			}
 			newMetadata.Name = aliasChart.Alias
 		}
 		chartFound.Metadata = &newMetadata
@@ -286,6 +296,9 @@ func doProcessRequirementsEnabled(c *chart.Chart, v *chart.Config, path string)
 			chartDependencies = append(chartDependencies, chartDependency)
 		}
 		if req.Alias != "" {
+			if !aliasRegexp.MatchString(req.Alias) {
+				return fmt.Errorf("illegal alias name in %q", req.Name)
+			}
 			req.Name = req.Alias
 		}
 	}

@@ -370,11 +370,19 @@ func TestGetAliasDependency(t *testing.T) {
 	}
 
 	// Failure case
+	resetName := req.Dependencies[0].Name
 	req.Dependencies[0].Name = "something-else"
 	if aliasChart := getAliasDependency(c.Dependencies, req.Dependencies[0]); aliasChart != nil {
 		t.Fatalf("expected no chart but got %s", aliasChart.Metadata.Name)
 	}
 
+	// Add a bad alias name
+	req.Dependencies[0].Name = resetName
+	req.Dependencies[0].Alias = "$foobar"
+	if aliasChart := getAliasDependency(c.Dependencies, req.Dependencies[0]); aliasChart != nil {
+		t.Fatalf("expected no chart but got %s", aliasChart.Metadata.Name)
+	}
+
 	req.Dependencies[0].Version = "something else which is not in the compatible range"
 	if version.IsCompatibleRange(req.Dependencies[0].Version, aliasChart.Metadata.Version) {
 		t.Fatalf("Dependency chart version which is not in the compatible range should cause a failure other than a success ")
@@ -516,3 +524,16 @@ func TestDependentChartsWithSomeSubchartsSpecifiedInRequirements(t *testing.T) {
 	}
 
 }
+
+func TestAliasRegexp(t *testing.T) {
+	for name, shouldPass := range map[string]bool{
+		"abcdefghijklmnopqrstuvwxyzABCDEFG0987654321_-": true,
+		"$foo":     false,
+		"bar$":     false,
+		"foo\nbar": false,
+	} {
+		if aliasRegexp.MatchString(name) != shouldPass {
+			t.Errorf("name %q failed to pass its test", name)
+		}
+	}
+}

@@ -16,6 +16,7 @@ limitations under the License.
 package plugin // import "k8s.io/helm/pkg/plugin"
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -141,13 +142,22 @@ func LoadAll(basedir string) ([]*Plugin, error) {
 		return plugins, nil
 	}
 
+	loaded := map[string]bool{}
 	for _, yaml := range matches {
 		dir := filepath.Dir(yaml)
 		p, err := LoadDir(dir)
+		pname := p.Metadata.Name
 		if err != nil {
 			return plugins, err
 		}
+
+		if _, ok := loaded[pname]; ok {
+			fmt.Fprintf(os.Stderr, "A plugin named %q already exists. Skipping.", pname)
+			continue
+		}
+
 		plugins = append(plugins, p)
+		loaded[pname] = true
 	}
 	return plugins, nil
 }

@@ -137,6 +137,7 @@ func TestLoadAll(t *testing.T) {
 		t.Fatalf("Could not load %q: %s", basedir, err)
 	}
 
+	// This would fail if the duplicate plugin were loaded.
 	if l := len(plugs); l != 3 {
 		t.Fatalf("expected 3 plugins, found %d", l)
 	}

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+echo "Hello from a Helm plugin"
+
+echo "PARAMS"
+echo $*
+
+echo "ENVIRONMENT"
+echo $TILLER_HOST
+echo $HELM_HOME
+
+$HELM_BIN --host $TILLER_HOST ls --all
+

@@ -0,0 +1,11 @@
+name: "hello"
+version: "0.1.0"
+usage: "usage"
+description: |-
+  description
+command: "$HELM_PLUGIN_SELF/hello.sh"
+useTunnel: true
+ignoreFlags: true
+install: "echo installing..."
+hooks:
+  install: "echo installing..."

@@ -30,6 +30,7 @@ import (
 
 	"github.com/Masterminds/semver"
 	"github.com/ghodss/yaml"
+	yaml2 "gopkg.in/yaml.v2"
 
 	"k8s.io/helm/pkg/chartutil"
 	"k8s.io/helm/pkg/proto/hapi/chart"
@@ -83,6 +84,14 @@ type IndexFile struct {
 	PublicKeys []string                 `json:"publicKeys,omitempty"`
 }
 
+// IndexValidation is used to validate the integrity of an index file
+type IndexValidation struct {
+	APIVersion string                 `yaml:"apiVersion"`
+	Generated  time.Time              `yaml:"generated"`
+	Entries    map[string]interface{} `yaml:"entries"`
+	PublicKeys []string               `yaml:"publicKeys,omitempty"`
+}
+
 // NewIndexFile initializes an index.
 func NewIndexFile() *IndexFile {
 	return &IndexFile{
@@ -283,9 +292,14 @@ func IndexDirectory(dir, baseURL string) (*IndexFile, error) {
 // This will fail if API Version is not set (ErrNoAPIVersion) or if the unmarshal fails.
 func loadIndex(data []byte) (*IndexFile, error) {
 	i := &IndexFile{}
+	if err := validateIndex(data); err != nil {
+		return i, err
+	}
+
 	if err := yaml.Unmarshal(data, i); err != nil {
 		return i, err
 	}
+
 	i.SortEntries()
 	if i.APIVersion == "" {
 		// When we leave Beta, we should remove legacy support and just
@@ -296,6 +310,16 @@ func loadIndex(data []byte) (*IndexFile, error) {
 	return i, nil
 }
 
+// validateIndex validates that the index is well-formed.
+func validateIndex(data []byte) error {
+	// This is done ONLY for validation. We need to use ghodss/yaml for the actual parsing.
+	validation := &IndexValidation{}
+	if err := yaml2.UnmarshalStrict(data, validation); err != nil {
+		return err
+	}
+	return nil
+}
+
 // unversionedEntry represents a deprecated pre-Alpha.5 format.
 //
 // This will be removed prior to v2.0.0

@@ -422,3 +422,19 @@ func TestIndexAdd(t *testing.T) {
 		t.Errorf("Expected http://example.com/charts/deis-0.1.0.tgz, got %s", i.Entries["deis"][0].URLs[0])
 	}
 }
+
+const mockDuplicateIndex = `
+entries:
+  foo: {}
+  bar: {}
+  baz: {}
+  bar: {}
+`
+
+func TestValidateIndex(t *testing.T) {
+	expect := `key "bar" already set in map`
+	err := validateIndex([]byte(mockDuplicateIndex))
+	if strings.Contains(expect, err.Error()) {
+		t.Errorf("Unexpected error: %s", err)
+	}
+}