Interpolating service tags

client/driver/executor/executor.go

@@ -388,6 +388,9 @@ func (e *UniversalExecutor) SyncServices(ctx *ConsulContext) error {
 		cs.SetDelegatedChecks(e.createCheckMap(), e.createCheck)
 		e.consulService = cs
 	}
+	if e.ctx != nil {
+		e.interpolateServices(e.ctx.Task)
+	}
 	err := e.consulService.SyncTask(e.ctx.Task)
 	go e.consulService.PeriodicSync()
 	return err
@@ -541,3 +544,10 @@ func (e *UniversalExecutor) createCheck(check *structs.ServiceCheck, checkID str
 	}
 	return nil, fmt.Errorf("couldn't create check for %v", check.Name)
 }
+
+func (e *UniversalExecutor) interpolateServices(task *structs.Task) {
+	e.ctx.TaskEnv.Build()
+	for _, service := range task.Services {
+		service.Tags = e.ctx.TaskEnv.ParseAndReplace(service.Tags)
+	}
+}

client/driver/executor/executor_test.go

@@ -5,6 +5,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -267,3 +268,18 @@ func TestExecutor_MakeExecutable(t *testing.T) {
 		t.Fatalf("expected permissions %v; got %v", err)
 	}
 }
+
+func TestExecutorInterpolateServices(t *testing.T) {
+	task := mock.Job().TaskGroups[0].Tasks[0]
+	// Make a fake exececutor
+	ctx := testExecutorContext(t)
+	defer ctx.AllocDir.Destroy()
+	executor := NewExecutor(log.New(os.Stdout, "", log.LstdFlags))
+
+	executor.(*UniversalExecutor).ctx = ctx
+	executor.(*UniversalExecutor).interpolateServices(task)
+	expected := []string{"pci:true", "datacenter:dc1"}
+	if !reflect.DeepEqual(task.Services[0].Tags, expected) {
+		t.Fatalf("expected: %v, actual: %v", expected, task.Services[0].Tags)
+	}
+}

helper/args/args.go

@@ -9,10 +9,10 @@ var (
 // ReplaceEnv takes an arg and replaces all occurences of environment variables.
 // If the variable is found in the passed map it is replaced, otherwise the
 // original string is returned.
-func ReplaceEnv(arg string, environents ...map[string]string) string {
+func ReplaceEnv(arg string, environments ...map[string]string) string {
 	return envRe.ReplaceAllStringFunc(arg, func(arg string) string {
 		stripped := arg[2 : len(arg)-1]
-		for _, env := range environents {
+		for _, env := range environments {
 			if value, ok := env[stripped]; ok {
 				return value
 			}

nomad/mock/mock.go

@@ -96,6 +96,7 @@ func Job() *structs.Job {
 							{
 								Name:      "${TASK}-frontend",
 								PortLabel: "http",
+								Tags:      []string{"pci:${meta.pci-dss}", "datacenter:${node.datacenter}"},
 							},
 							{
 								Name:      "${TASK}-admin",