Add blueprint validation logic to deferPhases as well (#1370)

* Support `deferPhase` in blueprint action

Blueprints can now define `deferPhase` for every action
that would be run once all (some in case of failure) the
phases of a blueprint action are run.

* Update docs for deferPhase changes

* Refactor code and add test for utility functions

* Address review comment, modularise functions

* Address review comment, reword comments and docs

* Add blueprint validation logic to deferPhases as well

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

pkg/blueprint/validate/validate.go

@@ -41,6 +41,22 @@ func Do(bp *crv1alpha1.Blueprint, funcVersion string) error {
 			return errors.Wrapf(err, "%s action %s", BPValidationErr, name)
 		}
 
+		// validate deferPhase's argument
+		deferPhase, err := kanister.GetDeferPhase(*bp, name, funcVersion, param.TemplateParams{})
+		if err != nil {
+			utils.PrintStage(fmt.Sprintf("validation of action %s", name), utils.Fail)
+			return errors.Wrapf(err, "%s action %s", BPValidationErr, name)
+		}
+
+		if deferPhase != nil {
+			if err := deferPhase.Validate(action.DeferPhase.Args); err != nil {
+				utils.PrintStage(fmt.Sprintf("validation of phase %s in action %s", deferPhase.Name(), name), utils.Fail)
+				return errors.Wrapf(err, "%s phase %s in action %s", BPValidationErr, deferPhase.Name(), name)
+			}
+			utils.PrintStage(fmt.Sprintf("validation of phase %s in action %s", deferPhase.Name(), name), utils.Pass)
+		}
+
+		// validate main phases' arguments
 		for i, phase := range phases {
 			// validate function's mandatory arguments
 			if err := phase.Validate(action.Phases[i].Args); err != nil {

pkg/blueprint/validate/validate_test.go

@@ -35,6 +35,7 @@ func (v *ValidateBlueprint) TestValidate(c *C) {
 		phases      []crv1alpha1.BlueprintPhase
 		err         Checker
 		errContains string
+		deferPhase  *crv1alpha1.BlueprintPhase
 	}{
 		{
 			phases: []crv1alpha1.BlueprintPhase{
@@ -140,9 +141,80 @@ func (v *ValidateBlueprint) TestValidate(c *C) {
 			errContains: "Required arg missing: command",
 			err:         NotNil,
 		},
+		{
+			phases: []crv1alpha1.BlueprintPhase{
+				{
+					Func: "PrepareData",
+					Name: "50",
+					Args: map[string]interface{}{
+						"namespace": "",
+						"image":     "",
+					},
+				},
+			},
+			errContains: "Required arg missing: command",
+			err:         NotNil,
+			deferPhase: &crv1alpha1.BlueprintPhase{
+				Func: "PrepareData",
+				Name: "51",
+				Args: map[string]interface{}{
+					"namespace": "",
+					"image":     "",
+				},
+			},
+		},
+		{
+			phases: []crv1alpha1.BlueprintPhase{
+				{
+					Func: "PrepareData",
+					Name: "60",
+					Args: map[string]interface{}{
+						"namespace": "",
+						"image":     "",
+						"command":   "",
+					},
+				},
+			},
+			errContains: "Required arg missing: command",
+			err:         NotNil,
+			deferPhase: &crv1alpha1.BlueprintPhase{
+				Func: "PrepareData",
+				Name: "61",
+				Args: map[string]interface{}{
+					"namespace": "",
+					"image":     "",
+				},
+			},
+		},
+		{
+			phases: []crv1alpha1.BlueprintPhase{
+				{
+					Func: "PrepareData",
+					Name: "70",
+					Args: map[string]interface{}{
+						"namespace": "",
+						"image":     "",
+						"command":   "",
+					},
+				},
+			},
+			err: IsNil,
+			deferPhase: &crv1alpha1.BlueprintPhase{
+				Func: "PrepareData",
+				Name: "71",
+				Args: map[string]interface{}{
+					"namespace": "",
+					"image":     "",
+					"command":   "",
+				},
+			},
+		},
 	} {
 		bp := blueprint()
 		bp.Actions["backup"].Phases = tc.phases
+		if tc.deferPhase != nil {
+			bp.Actions["backup"].DeferPhase = tc.deferPhase
+		}
 		err := Do(bp, kanister.DefaultVersion)
 		if err != nil {
 			c.Assert(strings.Contains(err.Error(), tc.errContains), Equals, true)