Define the self-sharding template in a variable, not an external file.

This will be done incrementally for all templates, making the
controller executable wholly self-contained.

pkg/varnish/vcl/self-shard.tmpl → pkg/varnish/vcl/self_shard_tmpl.go

+/*
+ * Copyright (c) 2020 UPLEX Nils Goroll Systemoptimierung
+ * All rights reserved
+ *
+ * Author: Geoffrey Simmons <geoffrey.simmons@uplex.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
 
+package vcl
+
+import "text/template"
+
+const selfShardTmplSrc = `
 import std;
 import directors;
 
@@ -139,3 +171,9 @@ sub vcl_deliver {
 		return (deliver);
 	}
 }
+`
+
+const selfShardName = "self-sharding"
+
+var shardTmpl = template.Must(template.New(selfShardName).
+	Parse(selfShardTmplSrc))

pkg/varnish/vcl/template.go

@@ -146,7 +146,6 @@ var fMap = template.FuncMap{
 
 const (
 	ingTmplSrc     = "vcl.tmpl"
-	shardTmplSrc   = "self-shard.tmpl"
 	authTmplSrc    = "auth.tmpl"
 	aclTmplSrc     = "acl.tmpl"
 	rewriteTmplSrc = "rewrite.tmpl"
@@ -160,7 +159,6 @@ const (
 
 var (
 	ingressTmpl *template.Template
-	shardTmpl   *template.Template
 	authTmpl    *template.Template
 	aclTmpl     *template.Template
 	rewriteTmpl *template.Template
@@ -172,7 +170,6 @@ var (
 func InitTemplates(tmplDir string) error {
 	var err error
 	ingTmplPath := path.Join(tmplDir, ingTmplSrc)
-	shardTmplPath := path.Join(tmplDir, shardTmplSrc)
 	authTmplPath := path.Join(tmplDir, authTmplSrc)
 	aclTmplPath := path.Join(tmplDir, aclTmplSrc)
 	rewriteTmplPath := path.Join(tmplDir, rewriteTmplSrc)
@@ -183,11 +180,6 @@ func InitTemplates(tmplDir string) error {
 	if err != nil {
 		return err
 	}
-	shardTmpl, err = template.New(shardTmplSrc).
-		Funcs(fMap).ParseFiles(shardTmplPath)
-	if err != nil {
-		return err
-	}
 	authTmpl, err = template.New(authTmplSrc).
 		Funcs(fMap).ParseFiles(authTmplPath)
 	if err != nil {

pkg/varnish/vcl/vcl_test.go

@@ -155,14 +155,8 @@ var varnishCluster = ShardCluster{
 func TestShardTemplate(t *testing.T) {
 	var buf bytes.Buffer
 	gold := "shard.golden"
-	tmplName := "self-shard.tmpl"
 
-	tmpl, err := template.New(tmplName).Funcs(fMap).ParseFiles(tmplName)
-	if err != nil {
-		t.Error("Cannot parse shard template:", err)
-		return
-	}
-	if err := tmpl.Execute(&buf, varnishCluster); err != nil {
+	if err := shardTmpl.Execute(&buf, varnishCluster); err != nil {
 		t.Error("cluster template Execute():", err)
 		return
 	}
@@ -182,15 +176,9 @@ func TestShardTemplate(t *testing.T) {
 func TestPrimaryOnlyShardTemplate(t *testing.T) {
 	var buf bytes.Buffer
 	gold := "primaryonly_shard.golden"
-	tmplName := "self-shard.tmpl"
 
-	tmpl, err := template.New(tmplName).Funcs(fMap).ParseFiles(tmplName)
-	if err != nil {
-		t.Error("Cannot parse shard template:", err)
-		return
-	}
 	varnishCluster.PrimaryOnly = true
-	if err := tmpl.Execute(&buf, varnishCluster); err != nil {
+	if err := shardTmpl.Execute(&buf, varnishCluster); err != nil {
 		t.Error("cluster template Execute():", err)
 		return
 	}