The fully qualified version of a vcl.Spec includes its creation time.

pkg/varnish/vcl/backends.tmpl

@@ -80,7 +80,3 @@ sub vcl_init {
 	rr_baz_backends.add_backend({{$name}});
 {{- end}}
 }
-
-sub set_version {
-	set resp.http.X-VCL-Version = "{{fqVersion .}}";
-}

pkg/varnish/vcl/spec.go

@@ -34,6 +34,11 @@ import (
 	"hash"
 	"math/big"
 	"sort"
+	"time"
+)
+
+const (
+	RFC3339Micro = "2006-01-02T15:04:05.999999Z07:00"
 )
 
 // Meta represents a k8s object's Metadata
@@ -106,6 +111,8 @@ type Spec struct {
 	Main string
 	// Version is the version string of the VCL config.
 	Version string
+	// Created is the time at which this Spec was created.
+	Created time.Time
 }
 
 // DeepHash computes a alphanumerically encoded hash value from a Spec
@@ -141,8 +148,8 @@ func (spec Spec) DeepHash() string {
 }
 
 // FQVersion returns a fully qualified version -- the version string
-// appended with the deep hash of the Spec (since the same VCL version
-// may be used with different backend configurations).
+// appended with the creation time of the Spec (since the same VCL
+// version may be used with different backend configurations).
 func (spec Spec) FQVersion() string {
-	return spec.Version + "-" + spec.DeepHash()
+	return spec.Version + "-" + spec.Created.Format(RFC3339Micro)
 }

pkg/varnish/vcl/testdata/backends.golden

@@ -80,7 +80,3 @@ sub vcl_init {
 	new rr_baz_backends = directors.round_robin();
 	rr_baz_backends.add_backend(baz-5ff49fcd4-hx7lj);
 }
-
-sub set_version {
-	set resp.http.X-VCL-Version = "4.7.11-aspw8srL8xsO5ObnCdofc5hQCMfOvqmySYu6YM";
-}

pkg/varnish/vcl/vcl_test.go

@@ -34,7 +34,9 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
+	"time"
 )
 
 func cmpGold(got []byte, goldfile string) (bool, error) {
@@ -60,8 +62,9 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
-var dfbSpec = Spec{
+var testSpec = Spec{
 	Version: "4.7.11",
+	Created: time.Unix(1136239445, 123456000),
 	Services: map[string]Service{
 		"bar-service": Service{
 			Meta: Meta{
@@ -141,7 +144,7 @@ var dfbSpec = Spec{
 func TestTemplate(t *testing.T) {
 	var buf bytes.Buffer
 	gold := "backends.golden"
-	if err := tmpl.Execute(&buf, dfbSpec); err != nil {
+	if err := tmpl.Execute(&buf, testSpec); err != nil {
 		t.Fatal("Execute():", err)
 	}
 	ok, err := cmpGold(buf.Bytes(), gold)
@@ -155,3 +158,17 @@ func TestTemplate(t *testing.T) {
 		}
 	}
 }
+
+func TestFQVersion(t *testing.T) {
+	fqVersion := testSpec.FQVersion()
+	if !strings.HasPrefix(fqVersion, testSpec.Version + "-") {
+		t.Fatal("FQVersion(): does not begin with spec.Version + "+
+			"\"-\":", fqVersion)
+	}
+	versionSlice := strings.SplitN(fqVersion, "-", 2)
+	if created, err := time.Parse(RFC3339Micro, versionSlice[1]); err != nil {
+		t.Fatal("FQVersion: cannot parse timestamp", err)
+	} else if testSpec.Created != created {
+		t.Fatal("FQVersion(): timestamp != Spec.Created", fqVersion)
+	}
+}