nomad: additional constraint validation

nomad/structs/structs.go

@@ -4,11 +4,13 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
 	"github.com/hashicorp/go-msgpack/codec"
 	"github.com/hashicorp/go-multierror"
+	"github.com/hashicorp/go-version"
 )
 
 var (
@@ -809,6 +811,12 @@ func (j *Job) Validate() error {
 	if len(j.TaskGroups) == 0 {
 		mErr.Errors = append(mErr.Errors, errors.New("Missing job task groups"))
 	}
+	for idx, constr := range j.Constraints {
+		if err := constr.Validate(); err != nil {
+			outer := fmt.Errorf("Constraint %d validation failed: %s", idx+1, err)
+			mErr.Errors = append(mErr.Errors, outer)
+		}
+	}
 
 	// Check for duplicate task groups
 	taskGroups := make(map[string]int)
@@ -918,6 +926,12 @@ func (tg *TaskGroup) Validate() error {
 	if len(tg.Tasks) == 0 {
 		mErr.Errors = append(mErr.Errors, errors.New("Missing tasks for task group"))
 	}
+	for idx, constr := range tg.Constraints {
+		if err := constr.Validate(); err != nil {
+			outer := fmt.Errorf("Constraint %d validation failed: %s", idx+1, err)
+			mErr.Errors = append(mErr.Errors, outer)
+		}
+	}
 
 	// Check for duplicate tasks
 	tasks := make(map[string]int)
@@ -997,6 +1011,12 @@ func (t *Task) Validate() error {
 	if t.Resources == nil {
 		mErr.Errors = append(mErr.Errors, errors.New("Missing task resources"))
 	}
+	for idx, constr := range t.Constraints {
+		if err := constr.Validate(); err != nil {
+			outer := fmt.Errorf("Constraint %d validation failed: %s", idx+1, err)
+			mErr.Errors = append(mErr.Errors, outer)
+		}
+	}
 	return mErr.ErrorOrNil()
 }
 
@@ -1015,6 +1035,26 @@ func (c *Constraint) String() string {
 	return fmt.Sprintf("%s %s %s", c.LTarget, c.Operand, c.RTarget)
 }
 
+func (c *Constraint) Validate() error {
+	var mErr multierror.Error
+	if c.Operand == "" {
+		mErr.Errors = append(mErr.Errors, errors.New("Missing constraint operand"))
+	}
+
+	// Perform additional validation based on operand
+	switch c.Operand {
+	case "regexp":
+		if _, err := regexp.Compile(c.RTarget); err != nil {
+			mErr.Errors = append(mErr.Errors, fmt.Errorf("Regular expression failed to compile: %v", err))
+		}
+	case "version":
+		if _, err := version.NewConstraint(c.RTarget); err != nil {
+			mErr.Errors = append(mErr.Errors, fmt.Errorf("Version constraint is invalid: %v", err))
+		}
+	}
+	return mErr.ErrorOrNil()
+}
+
 const (
 	AllocDesiredStatusRun    = "run"    // Allocation should run
 	AllocDesiredStatusStop   = "stop"   // Allocation should stop

nomad/structs/structs_test.go

@@ -125,6 +125,43 @@ func TestTask_Validate(t *testing.T) {
 	}
 }
 
+func TestConstraint_Validate(t *testing.T) {
+	c := &Constraint{}
+	err := c.Validate()
+	mErr := err.(*multierror.Error)
+	if !strings.Contains(mErr.Errors[0].Error(), "Missing constraint operand") {
+		t.Fatalf("err: %s", err)
+	}
+
+	c = &Constraint{
+		LTarget: "$attr.kernel.name",
+		RTarget: "linux",
+		Operand: "=",
+	}
+	err = c.Validate()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Perform additional regexp validation
+	c.Operand = "regexp"
+	c.RTarget = "(foo"
+	err = c.Validate()
+	mErr = err.(*multierror.Error)
+	if !strings.Contains(mErr.Errors[0].Error(), "missing closing") {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Perform version validation
+	c.Operand = "version"
+	c.RTarget = "~> foo"
+	err = c.Validate()
+	mErr = err.(*multierror.Error)
+	if !strings.Contains(mErr.Errors[0].Error(), "Malformed constraint") {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 func TestResource_NetIndex(t *testing.T) {
 	r := &Resources{
 		Networks: []*NetworkResource{