Add list-changed command (#98)

Allows to identify chart changes before actually running
lint or install commands. This can be useful in the following
cases:

* In a CI setup where kind clusters are spun up on the fly,
  this makes it possible to decide whether a cluster is necessary
  at all. A PR may only contain changes that are not relevant
  to any charts.
* By knowing upfront which charts have changed, it is
  possible to load a per-chart CI configuration which would
  allows us to determine the number of nodes needed in a kind
  cluster. For most charts, one node is enough, but in certain
  scenarios, especially for StatefulSets, we may want to test
  with pod anti-affinity where replicas have to be spread across
  multiple nodes.

Signed-off-by: Reinhard Nägele <unguiculus@gmail.com>

app/cmd/install.go

@@ -72,7 +72,7 @@ func addInstallFlags(flags *flag.FlagSet) {
 func install(cmd *cobra.Command, args []string) {
 	fmt.Println("Installing charts...")
 
-	configuration, err := config.LoadConfiguration(cfgFile, cmd)
+	configuration, err := config.LoadConfiguration(cfgFile, cmd, true)
 	if err != nil {
 		fmt.Printf("Error loading configuration: %s\n", err)
 		os.Exit(1)

app/cmd/lint.go

@@ -75,7 +75,7 @@ func addLintFlags(flags *flag.FlagSet) {
 func lint(cmd *cobra.Command, args []string) {
 	fmt.Println("Linting charts...")
 
-	configuration, err := config.LoadConfiguration(cfgFile, cmd)
+	configuration, err := config.LoadConfiguration(cfgFile, cmd, true)
 	if err != nil {
 		fmt.Printf("Error loading configuration: %s\n", err)
 		os.Exit(1)

app/cmd/lintAndInstall.go

@@ -43,7 +43,7 @@ func newLintAndInstallCmd() *cobra.Command {
 func lintAndInstall(cmd *cobra.Command, args []string) {
 	fmt.Println("Linting and installing charts...")
 
-	configuration, err := config.LoadConfiguration(cfgFile, cmd)
+	configuration, err := config.LoadConfiguration(cfgFile, cmd, true)
 	if err != nil {
 		fmt.Printf("Error loading configuration: %s\n", err)
 		os.Exit(1)

app/cmd/listChanged.go

@@ -0,0 +1,59 @@
+// Copyright The Helm Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cmd
+
+import (
+	"fmt"
+	"github.com/MakeNowJust/heredoc"
+	"os"
+
+	"github.com/helm/chart-testing/pkg/chart"
+	"github.com/helm/chart-testing/pkg/config"
+	"github.com/spf13/cobra"
+)
+
+func newListChangedCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "list-changed",
+		Aliases: []string{"ls-changed", "lsc"},
+		Short:   "List changed charts",
+		Long: heredoc.Doc(`
+			"List changed charts based on configured charts directories,
+			"remote, and target branch`),
+		Run: listChanged,
+	}
+
+	flags := cmd.Flags()
+	addCommonFlags(flags)
+	return cmd
+}
+
+func listChanged(cmd *cobra.Command, args []string) {
+	configuration, err := config.LoadConfiguration(cfgFile, cmd, false)
+	if err != nil {
+		fmt.Printf("Error loading configuration: %s\n", err)
+		os.Exit(1)
+	}
+
+	testing := chart.NewTesting(*configuration)
+	chartDirs, err := testing.ComputeChangedChartDirectories()
+	if err != nil {
+		os.Exit(1)
+	}
+
+	for _, dir := range chartDirs {
+		fmt.Println(dir)
+	}
+}

app/cmd/root.go

@@ -44,6 +44,7 @@ func NewRootCmd() *cobra.Command {
 	cmd.AddCommand(newLintCmd())
 	cmd.AddCommand(newInstallCmd())
 	cmd.AddCommand(newLintAndInstallCmd())
+	cmd.AddCommand(newListChangedCmd())
 	cmd.AddCommand(newVersionCmd())
 	cmd.AddCommand(newGenerateDocsCmd())
 
@@ -58,20 +59,27 @@ func Execute() {
 	}
 }
 
-func addCommonLintAndInstallFlags(flags *pflag.FlagSet) {
+func addCommonFlags(flags *pflag.FlagSet) {
 	flags.StringVar(&cfgFile, "config", "", "Config file")
 	flags.String("remote", "origin", "The name of the Git remote used to identify changed charts")
 	flags.String("target-branch", "master", "The name of the target branch used to identify changed charts")
+	flags.StringSlice("chart-dirs", []string{"charts"}, heredoc.Doc(`
+		Directories containing Helm charts. May be specified multiple times
+		or separate values with commas`))
+	flags.StringSlice("excluded-charts", []string{}, heredoc.Doc(`
+		Charts that should be skipped. May be specified multiple times
+		or separate values with commas`))
+}
+
+func addCommonLintAndInstallFlags(flags *pflag.FlagSet) {
+	addCommonFlags(flags)
 	flags.Bool("all", false, heredoc.Doc(`
 		Process all charts except those explicitly excluded.
 		Disables changed charts detection and version increment checking`))
 	flags.StringSlice("charts", []string{}, heredoc.Doc(`
 		Specific charts to test. Disables changed charts detection and
 		version increment checking. May be specified multiple times
 		or separate values with commas`))
-	flags.StringSlice("chart-dirs", []string{"charts"}, heredoc.Doc(`
-		Directories containing Helm charts. May be specified multiple times
-		or separate values with commas`))
 	flags.StringSlice("chart-repos", []string{}, heredoc.Doc(`
 		Additional chart repositories for dependency resolutions.
 		Repositories should be formatted as 'name=url' (ex: local=http://127.0.0.1:8879/charts).
@@ -81,9 +89,6 @@ func addCommonLintAndInstallFlags(flags *pflag.FlagSet) {
 		specified on a per-repo basis with an equals sign as delimiter
 		(e.g. 'myrepo=--username test --password secret'). May be specified
 		multiple times or separate values with commas`))
-	flags.StringSlice("excluded-charts", []string{}, heredoc.Doc(`
-		Charts that should be skipped. May be specified multiple times
-		or separate values with commas`))
 	flags.Bool("debug", false, heredoc.Doc(`
 		Print CLI calls of external tools to stdout (Note: depending on helm-extra-args
 		passed, this may reveal sensitive data)`))

doc/ct.md

@@ -23,6 +23,7 @@ in given chart directories.
 * [ct install](ct_install.md)	 - Install and test a chart
 * [ct lint](ct_lint.md)	 - Lint and validate a chart
 * [ct lint-and-install](ct_lint-and-install.md)	 - Lint, install, and test a chart
+* [ct list-changed](ct_list-changed.md)	 - List changed charts
 * [ct version](ct_version.md)	 - Print version information
 
-###### Auto generated by spf13/cobra on 18-Jan-2019
+###### Auto generated by spf13/cobra on 31-Jan-2019

doc/ct_install.md

@@ -62,4 +62,4 @@ ct install [flags]
 
 * [ct](ct.md)	 - The Helm chart testing tool
 
-###### Auto generated by spf13/cobra on 18-Jan-2019
+###### Auto generated by spf13/cobra on 31-Jan-2019

doc/ct_lint-and-install.md

@@ -61,4 +61,4 @@ ct lint-and-install [flags]
 
 * [ct](ct.md)	 - The Helm chart testing tool
 
-###### Auto generated by spf13/cobra on 18-Jan-2019
+###### Auto generated by spf13/cobra on 31-Jan-2019

doc/ct_lint.md

@@ -65,4 +65,4 @@ ct lint [flags]
 
 * [ct](ct.md)	 - The Helm chart testing tool
 
-###### Auto generated by spf13/cobra on 18-Jan-2019
+###### Auto generated by spf13/cobra on 31-Jan-2019

doc/ct_list-changed.md

@@ -0,0 +1,31 @@
+## ct list-changed
+
+List changed charts
+
+### Synopsis
+
+"List changed charts based on configured charts directories,
+"remote, and target branch
+
+```
+ct list-changed [flags]
+```
+
+### Options
+
+```
+      --chart-dirs strings        Directories containing Helm charts. May be specified multiple times
+                                  or separate values with commas (default [charts])
+      --config string             Config file
+      --excluded-charts strings   Charts that should be skipped. May be specified multiple times
+                                  or separate values with commas
+  -h, --help                      help for list-changed
+      --remote string             The name of the Git remote used to identify changed charts (default "origin")
+      --target-branch string      The name of the target branch used to identify changed charts (default "master")
+```
+
+### SEE ALSO
+
+* [ct](ct.md)	 - The Helm chart testing tool
+
+###### Auto generated by spf13/cobra on 31-Jan-2019

doc/ct_version.md

@@ -20,4 +20,4 @@ ct version [flags]
 
 * [ct](ct.md)	 - The Helm chart testing tool
 
-###### Auto generated by spf13/cobra on 18-Jan-2019
+###### Auto generated by spf13/cobra on 31-Jan-2019

pkg/config/config.go

@@ -60,7 +60,7 @@ type Configuration struct {
 	ReleaseLabel          string   `mapstructure:"release-label"`
 }
 
-func LoadConfiguration(cfgFile string, cmd *cobra.Command) (*Configuration, error) {
+func LoadConfiguration(cfgFile string, cmd *cobra.Command, printConfig bool) (*Configuration, error) {
 	v := viper.New()
 
 	cmd.Flags().VisitAll(func(flag *flag.Flag) {
@@ -92,7 +92,9 @@ func LoadConfiguration(cfgFile string, cmd *cobra.Command) (*Configuration, erro
 			return nil, errors.Wrap(err, "Error loading config file")
 		}
 	} else {
-		fmt.Println("Using config file: ", v.ConfigFileUsed())
+		if printConfig {
+			fmt.Println("Using config file: ", v.ConfigFileUsed())
+		}
 	}
 
 	cfg := &Configuration{}
@@ -134,7 +136,9 @@ func LoadConfiguration(cfgFile string, cmd *cobra.Command) (*Configuration, erro
 		cfg.CheckVersionIncrement = false
 	}
 
-	printCfg(cfg)
+	if printConfig {
+		printCfg(cfg)
+	}
 
 	return cfg, nil
 }

pkg/config/config_test.go

@@ -30,7 +30,7 @@ func TestUnmarshalJson(t *testing.T) {
 }
 
 func loadAndAssertConfigFromFile(t *testing.T, configFile string) {
-	cfg, _ := LoadConfiguration(configFile, &cobra.Command{})
+	cfg, _ := LoadConfiguration(configFile, &cobra.Command{}, true)
 
 	require.Equal(t, "origin", cfg.Remote)
 	require.Equal(t, "master", cfg.TargetBranch)