Merge pull request #9653 from Okhoshi/feat/reset-then-reuse-flag

feat(helm): Add --reset-then-reuse-values flag to 'helm upgrade'

cmd/helm/upgrade.go

@@ -252,6 +252,7 @@ func newUpgradeCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 	f.DurationVar(&client.Timeout, "timeout", 300*time.Second, "time to wait for any individual Kubernetes operation (like Jobs for hooks)")
 	f.BoolVar(&client.ResetValues, "reset-values", false, "when upgrading, reset the values to the ones built into the chart")
 	f.BoolVar(&client.ReuseValues, "reuse-values", false, "when upgrading, reuse the last release's values and merge in any overrides from the command line via --set and -f. If '--reset-values' is specified, this is ignored")
+	f.BoolVar(&client.ResetThenReuseValues, "reset-then-reuse-values", false, "when upgrading, reset the values to the ones built into the chart, apply the last release's values and merge in any overrides from the command line via --set and -f. If '--reset-values' or '--reuse-values' is specified, this is ignored")
 	f.BoolVar(&client.Wait, "wait", false, "if set, will wait until all Pods, PVCs, Services, and minimum number of Pods of a Deployment, StatefulSet, or ReplicaSet are in a ready state before marking the release as successful. It will wait for as long as --timeout")
 	f.BoolVar(&client.WaitForJobs, "wait-for-jobs", false, "if set and --wait enabled, will wait until all Jobs have been completed before marking the release as successful. It will wait for as long as --timeout")
 	f.BoolVar(&client.Atomic, "atomic", false, "if set, upgrade process rolls back changes made in case of failed upgrade. The --wait flag will be set automatically if --atomic is used")

pkg/action/upgrade.go

@@ -82,6 +82,8 @@ type Upgrade struct {
 	ResetValues bool
 	// ReuseValues will re-use the user's last supplied values.
 	ReuseValues bool
+	// ResetThenReuseValues will reset the values to the chart's built-ins then merge with user's last supplied values.
+	ResetThenReuseValues bool
 	// Recreate will (if true) recreate pods after a rollback.
 	Recreate bool
 	// MaxHistory limits the maximum number of revisions saved per release
@@ -552,6 +554,15 @@ func (u *Upgrade) reuseValues(chart *chart.Chart, current *release.Release, newV
 		return newVals, nil
 	}
 
+	// If the ResetThenReuseValues flag is set, we use the new chart's values, but we copy the old config's values over the new config's values.
+	if u.ResetThenReuseValues {
+		u.cfg.Log("merging values from old release to new values")
+
+		newVals = chartutil.CoalesceTables(newVals, current.Config)
+
+		return newVals, nil
+	}
+
 	if len(newVals) == 0 && len(current.Config) > 0 {
 		u.cfg.Log("copying values from %s (v%d) to new release.", current.Name, current.Version)
 		newVals = current.Config

pkg/action/upgrade_test.go

@@ -308,6 +308,59 @@ func TestUpgradeRelease_ReuseValues(t *testing.T) {
 	})
 }
 
+func TestUpgradeRelease_ResetThenReuseValues(t *testing.T) {
+	is := assert.New(t)
+
+	t.Run("reset then reuse values should work with values", func(t *testing.T) {
+		upAction := upgradeAction(t)
+
+		existingValues := map[string]interface{}{
+			"name":        "value",
+			"maxHeapSize": "128m",
+			"replicas":    2,
+		}
+		newValues := map[string]interface{}{
+			"name":        "newValue",
+			"maxHeapSize": "512m",
+			"cpu":         "12m",
+		}
+		newChartValues := map[string]interface{}{
+			"memory": "256m",
+		}
+		expectedValues := map[string]interface{}{
+			"name":        "newValue",
+			"maxHeapSize": "512m",
+			"cpu":         "12m",
+			"replicas":    2,
+		}
+
+		rel := releaseStub()
+		rel.Name = "nuketown"
+		rel.Info.Status = release.StatusDeployed
+		rel.Config = existingValues
+
+		err := upAction.cfg.Releases.Create(rel)
+		is.NoError(err)
+
+		upAction.ResetThenReuseValues = true
+		// setting newValues and upgrading
+		res, err := upAction.Run(rel.Name, buildChart(withValues(newChartValues)), newValues)
+		is.NoError(err)
+
+		// Now make sure it is actually upgraded
+		updatedRes, err := upAction.cfg.Releases.Get(res.Name, 2)
+		is.NoError(err)
+
+		if updatedRes == nil {
+			is.Fail("Updated Release is nil")
+			return
+		}
+		is.Equal(release.StatusDeployed, updatedRes.Info.Status)
+		is.Equal(expectedValues, updatedRes.Config)
+		is.Equal(newChartValues, updatedRes.Chart.Values)
+	})
+}
+
 func TestUpgradeRelease_Pending(t *testing.T) {
 	req := require.New(t)