accessor for step error in templating values (#16)

Signed-off-by: Pablo Pérez Schröder <[email protected]>

README.md

@@ -142,6 +142,8 @@ A user can be allowed to resolve a task in three ways:
 - `.resolver_input.[INPUT_NAME]`: the value of an input provided by the task's resolver
 - `.step.[STEP_NAME].output.foo`: field `foo` from the output of a named step
 - `.step.[STEP_NAME].metadata.HTTPStatus`: field `HTTPStatus` from the metadata of a named step
+- `.step.[STEP_NAME].children`: the collection of results from a 'foreach' step
+- `.step.[STEP_NAME].error`: error message from a failed step
 - `.config.[CONFIG_ITEM].bar`: field `bar` from a config item (configstore, see above)
 - `.iterator.foo`: field `foo` from the iterator in a loop (see `foreach` steps below)
 

engine/engine.go

@@ -348,6 +348,7 @@ func resolve(dbp zesty.DBProvider, res *resolution.Resolution, t *task.Task, deb
 			res.Values.SetOutput(s.Name, s.Output)
 			res.Values.SetMetadata(s.Name, s.Metadata)
 			res.Values.SetChildren(s.Name, s.Children)
+			res.Values.SetError(s.Name, s.Error)
 
 			// call after-run step logic
 			modifiedSteps := map[string]bool{

engine/engine_test.go

@@ -162,9 +162,12 @@ func TestSimpleTemplate(t *testing.T) {
 	res, err := runTask("simple.yaml", input, nil)
 
 	assert.Equal(t, nil, err)
-	assert.Equal(t, resolution.StateDone, res.State)
+	assert.Equal(t, resolution.StateError, res.State)
 	assert.Equal(t, step.StateDone, res.Steps["stepOne"].State)
 	assert.Equal(t, step.StateDone, res.Steps["stepTwo"].State)
+	assert.Equal(t, step.StateServerError, res.Steps["stepThree"].State)
+
+	assert.Equal(t, "FAIL!", res.Values.GetError("stepThree"))
 }
 
 func TestClientError(t *testing.T) {

engine/step/condition.go

@@ -18,7 +18,7 @@ const (
 	LT     = "LT"
 	GE     = "GE"
 	LE     = "LE"
-	REGEXP = "regexp"
+	REGEXP = "REGEXP"
 )
 
 type (
@@ -51,7 +51,7 @@ func (a *Assert) Eval(v *values.Values, item interface{}, stepName string) error
 		valStr := strings.Replace(string(val), "<no value>", "", -1)
 		expStr := strings.Replace(string(expected), "<no value>", "", -1)
 
-		switch a.Operator {
+		switch strings.ToUpper(a.Operator) { // normalized operator, accept both lower case and upper case from template
 		case EQ:
 			if valStr != expStr {
 				return ErrConditionNotMet(fmt.Sprintf("Condition not met: expected '%s', got '%s': %s", expStr, valStr, a.Message))
@@ -100,7 +100,7 @@ func (a *Assert) Eval(v *values.Values, item interface{}, stepName string) error
 // ie. the operator is among the accepted values listed above
 func (a *Assert) Valid() error {
 	if a != nil {
-		switch a.Operator {
+		switch strings.ToUpper(a.Operator) {
 		case EQ, NE, GT, LT, GE, LE:
 		case REGEXP:
 			if _, err := regexp.Compile(a.Expected); err != nil {

engine/templates_tests/simple.yaml

@@ -17,3 +17,11 @@ steps:
 			configuration:
 				output:
 					foo: baz
+	stepThree:
+		description: third step, fails
+		dependencies: [stepTwo]
+		action:
+			type: echo
+			configuration:
+				error_message: FAIL!
+

engine/values/values.go

@@ -9,8 +9,8 @@ import (
 
 	"github.com/Masterminds/sprig"
 	"github.com/juju/errors"
-	"github.com/robertkrimen/otto"
 	"github.com/ovh/utask"
+	"github.com/robertkrimen/otto"
 )
 
 // keys to store/retrieve data from a Values struct
@@ -26,6 +26,7 @@ const (
 	OutputKey   = "output"
 	MetadataKey = "metadata"
 	ChildrenKey = "children"
+	ErrorKey    = "error"
 )
 
 // Values is a container for all the live data of a running task
@@ -124,6 +125,21 @@ func (v *Values) UnsetChildren(stepName string) {
 	v.unsetStepData(stepName, ChildrenKey)
 }
 
+// GetError returns the error resulting from a failed step
+func (v *Values) GetError(stepName string) interface{} {
+	return v.getStepData(stepName, ErrorKey)
+}
+
+// SetChildren stores the error resulting from a failed step
+func (v *Values) SetError(stepName string, value interface{}) {
+	v.setStepData(stepName, ErrorKey, value)
+}
+
+// UnsetChildren empties the error from a failed step
+func (v *Values) UnsetError(stepName string) {
+	v.unsetStepData(stepName, ErrorKey)
+}
+
 func (v *Values) getStepData(stepName, field string) interface{} {
 	stepmap := v.m[StepKey].(map[string]interface{})
 	if stepmap[stepName] == nil {
@@ -213,6 +229,9 @@ func (v *Values) Apply(templateStr string, item interface{}, stepName string) ([
 
 		v.SetChildren(utask.This, v.GetChildren(stepName))
 		defer v.UnsetChildren(utask.This)
+
+		v.SetError(utask.This, v.GetError(stepName))
+		defer v.UnsetError(utask.This)
 	}
 
 	err = tmpl.Execute(b, v.m)

models/resolution/resolution.go

@@ -460,6 +460,7 @@ func (r *Resolution) setSteps(st map[string]*step.Step) {
 		r.Values.SetOutput(name, s.Output)
 		r.Values.SetMetadata(name, s.Metadata)
 		r.Values.SetChildren(name, s.Children)
+		r.Values.SetError(s.Name, s.Error)
 	}
 }