Add helmfile-fetch command to downloading and generating charts (#1734)

main.go

@@ -327,6 +327,28 @@ func main() {
 				return run.Lint(c)
 			}),
 		},
+		{
+			Name:  "fetch",
+			Usage: "fetch charts from state file",
+			Flags: []cli.Flag{
+				cli.IntFlag{
+					Name:  "concurrency",
+					Value: 0,
+					Usage: "maximum number of concurrent downloads of release charts",
+				},
+				cli.BoolFlag{
+					Name:  "skip-deps",
+					Usage: `skip running "helm repo update" and "helm dependency build"`,
+				},
+				cli.StringFlag{
+					Name:  "output-dir",
+					Usage: "directory to store charts (default: temporary directory which is deleted when the command terminates)",
+				},
+			},
+			Action: action(func(a *app.App, c configImpl) error {
+				return a.Fetch(c)
+			}),
+		},
 		{
 			Name:  "sync",
 			Usage: "sync all resources from state file (repos, releases and chart deps)",
@@ -553,6 +575,10 @@ func main() {
 					Value: "",
 					Usage: "output releases list as a json string",
 				},
+				cli.BoolFlag{
+					Name:  "keep-temp-dir",
+					Usage: "Keep temporary directory",
+				},
 			},
 			Action: action(func(run *app.App, c configImpl) error {
 				return run.ListReleases(c)
@@ -720,6 +746,10 @@ func (c configImpl) Output() string {
 	return c.c.String("output")
 }
 
+func (c configImpl) KeepTempDir() bool {
+	return c.c.Bool("keep-temp-dir")
+}
+
 // GlobalConfig
 
 func (c configImpl) HelmBinary() string {

pkg/app/app.go

@@ -291,6 +291,24 @@ func (a *App) Lint(c LintConfigProvider) error {
 	}, SetFilter(true))
 }
 
+func (a *App) Fetch(c FetchConfigProvider) error {
+	return a.ForEachState(func(run *Run) (ok bool, errs []error) {
+		prepErr := run.withPreparedCharts("pull", state.ChartPrepareOptions{
+			ForceDownload: true,
+			SkipRepos:     c.SkipDeps(),
+			SkipDeps:      c.SkipDeps(),
+			OutputDir:     c.OutputDir(),
+		}, func() {
+		})
+
+		if prepErr != nil {
+			errs = append(errs, prepErr)
+		}
+
+		return
+	}, SetFilter(true))
+}
+
 func (a *App) Sync(c SyncConfigProvider) error {
 	return a.ForEachState(func(run *Run) (ok bool, errs []error) {
 		prepErr := run.withPreparedCharts("sync", state.ChartPrepareOptions{

pkg/app/config.go

@@ -131,6 +131,13 @@ type LintConfigProvider interface {
 	concurrencyConfig
 }
 
+type FetchConfigProvider interface {
+	SkipDeps() bool
+	OutputDir() string
+
+	concurrencyConfig
+}
+
 type TemplateConfigProvider interface {
 	Args() string
 

pkg/app/run.go

@@ -2,13 +2,14 @@ package app
 
 import (
 	"fmt"
-	"github.com/roboll/helmfile/pkg/argparser"
-	"github.com/roboll/helmfile/pkg/helmexec"
-	"github.com/roboll/helmfile/pkg/state"
 	"io/ioutil"
 	"os"
 	"sort"
 	"strings"
+
+	"github.com/roboll/helmfile/pkg/argparser"
+	"github.com/roboll/helmfile/pkg/helmexec"
+	"github.com/roboll/helmfile/pkg/state"
 )
 
 type Run struct {
@@ -49,13 +50,20 @@ func (r *Run) withPreparedCharts(helmfileCommand string, opts state.ChartPrepare
 	}
 
 	// Create tmp directory and bail immediately if it fails
-	dir, err := ioutil.TempDir("", "")
+	var dir string
-	if err != nil {
+	if len(opts.OutputDir) == 0 {
-		return err
+		tempDir, err := ioutil.TempDir("", "helmfile*")
+		if err != nil {
+			return err
+		}
+		defer os.RemoveAll(tempDir)
+		dir = tempDir
+	} else {
+		dir = opts.OutputDir
+		fmt.Printf("Charts will be downloaded to: %s\n", dir)
 	}
-	defer os.RemoveAll(dir)
 
-	if _, err = r.state.TriggerGlobalPrepareEvent(helmfileCommand); err != nil {
+	if _, err := r.state.TriggerGlobalPrepareEvent(helmfileCommand); err != nil {
 		return err
 	}
 
@@ -82,7 +90,7 @@ func (r *Run) withPreparedCharts(helmfileCommand string, opts state.ChartPrepare
 
 	f()
 
-	_, err = r.state.TriggerGlobalCleanupEvent(helmfileCommand)
+	_, err := r.state.TriggerGlobalCleanupEvent(helmfileCommand)
 
 	return err
 }

pkg/state/state.go

@@ -896,6 +896,7 @@ type ChartPrepareOptions struct {
 	SkipResolve   bool
 	Wait          bool
 	WaitForJobs   bool
+	OutputDir     string
 }
 
 type chartPrepareResult struct {

pkg/state/temp_test.go

@@ -1,8 +1,9 @@
 package state
 
 import (
-	"github.com/google/go-cmp/cmp"
 	"testing"
+
+	"github.com/google/go-cmp/cmp"
 )
 
 func TestGenerateID(t *testing.T) {