Use a golden file to test VCL generation for Ingress rules.

cmd/varnish/vcl/testdata/ingressrule.golden

+vcl 4.0;
+
+import std;
+import directors;
+import re2;
+
+backend notfound {
+	# 192.0.2.0/24 reserved for docs & examples (RFC5737).
+	.host = "192.0.2.255";
+	.port = "80";
+}
+
+backend coffee-svc_192_2e_0_2e_2_2e_4 {
+	.host = "192.0.2.4";
+	.port = "80";
+}
+backend coffee-svc_192_2e_0_2e_2_2e_5 {
+	.host = "192.0.2.5";
+	.port = "80";
+}
+backend tea-svc_192_2e_0_2e_2_2e_1 {
+	.host = "192.0.2.1";
+	.port = "80";
+}
+backend tea-svc_192_2e_0_2e_2_2e_2 {
+	.host = "192.0.2.2";
+	.port = "80";
+}
+backend tea-svc_192_2e_0_2e_2_2e_3 {
+	.host = "192.0.2.3";
+	.port = "80";
+}
+
+
+sub vcl_init {
+	new hosts = re2.set(posix_syntax=true, literal=true, anchor=both);
+	hosts.add("cafe.example.com");
+	hosts.compile();
+
+	new coffee-svc_director = directors.round_robin();
+	coffee-svc_director.add_backend(coffee-svc_192_2e_0_2e_2_2e_4);
+	coffee-svc_director.add_backend(coffee-svc_192_2e_0_2e_2_2e_5);
+
+	new tea-svc_director = directors.round_robin();
+	tea-svc_director.add_backend(tea-svc_192_2e_0_2e_2_2e_1);
+	tea-svc_director.add_backend(tea-svc_192_2e_0_2e_2_2e_2);
+	tea-svc_director.add_backend(tea-svc_192_2e_0_2e_2_2e_3);
+
+	new cafe_2e_example_2e_com_url = re2.set(posix_syntax=true, anchor=start);
+	cafe_2e_example_2e_com_url.add("/coffee",
+				backend=coffee-svc_director.backend());
+	cafe_2e_example_2e_com_url.add("/tea",
+				backend=tea-svc_director.backend());
+	cafe_2e_example_2e_com_url.compile();
+}
+
+sub set_backend {
+	set req.backend_hint = notfound;
+	if (hosts.match(req.http.Host)) {
+		if (hosts.nmatches() != 1) {
+			# Fail fast when the match was not unique.
+			return (fail);
+		}
+		if (0 != 0) {
+			#
+		}
+		elsif (hosts.which() == 1) {
+			if (cafe_2e_example_2e_com_url.match(req.url)) {
+				set req.backend_hint = cafe_2e_example_2e_com_url.backend(select=FIRST);
+			}
+		}
+	}
+
+	if (req.backend_hint == notfound) {
+		return (synth(404));
+	}
+}
+
+sub vcl_miss {
+	call set_backend;
+}
+
+sub vcl_pass {
+	call set_backend;
+}

cmd/varnish/vcl/vcl_test.go

@@ -30,6 +30,8 @@ package vcl
 
 import (
 	"bytes"
+	"io/ioutil"
+	"path/filepath"
 	"testing"
 )
 
@@ -118,12 +120,25 @@ func TestTemplate(t *testing.T) {
 	if err := Tmpl.Execute(&buf, cafeSpec); err != nil {
 		t.Error("Execute():", err)
 	}
-	t.Log(string(buf.Bytes()))
+
+	goldpath := filepath.Join("testdata","ingressrule.golden")
+	gold, err := ioutil.ReadFile(goldpath)
+	if err != nil {
+		t.Fatalf("Error reading %s: %v", goldpath, err)
+	}
+	if !bytes.Equal(buf.Bytes(), gold) {
+		t.Errorf("Generated VCL for IngressSpec does not match gold "+
+			"file: %s", goldpath)
+		if testing.Verbose() {
+			t.Log("Generated VCL:", string(buf.Bytes()))
+			t.Log(goldpath, ":", string(gold))
+		}
+	}
 }
 
 func TestDeepHash(t *testing.T) {
-	t.Log("cafeSpec.DeepHash():", cafeSpec.DeepHash())
-	t.Log("cafeSpec2.DeepHash():", cafeSpec2.DeepHash())
+	t.Logf("cafeSpec.DeepHash(): %0x", cafeSpec.DeepHash())
+	t.Logf("cafeSpec2.DeepHash() %0x", cafeSpec2.DeepHash())
 	if cafeSpec.DeepHash() == cafeSpec2.DeepHash() {
 		t.Errorf("Distinct specs with different hashes: spec1=%+v "+
 			"spec2=%+v hash=%0x", cafeSpec, cafeSpec2,