feat(vcl): Support Custom VCL

src/fastly/include-util.js

@@ -13,11 +13,18 @@
 const fs = require('fs-extra');
 const path = require('path');
 
-module.exports = function include(srcfile) {
-  return fs.readFileSync(srcfile).toString().replace(/(synthetic \{"include:.*"\};)/g, (m) => {
+function synthetize(content, filePath) {
+  return content.replace(/(synthetic \{"include:.*"\};)/g, (m) => {
     const ref = m.replace(/^synthetic \{"include:/, '').replace(/"};$/, '');
-    const name = path.resolve(path.dirname(srcfile), ref);
-    const content = fs.readFileSync(name).toString();
-    return `synthetic {"${content}"};`;
+    const name = path.resolve(filePath, ref);
+    const c = fs.readFileSync(name).toString();
+    return `synthetic {"${c}"};`;
   });
-};
+}
+
+function include(srcfile) {
+  return synthetize(fs.readFileSync(srcfile).toString(), path.dirname(srcfile));
+}
+
+module.exports.include = include;
+module.exports.synthetize = synthetize;

src/fastly/vcl.js

@@ -10,7 +10,10 @@
  * governing permissions and limitations under the License.
  */
 const path = require('path');
-const include = require('./include-util');
+const {
+  include,
+  synthetize,
+} = require('./include-util');
 const {
   resolve,
   parameters,
@@ -26,9 +29,15 @@ async function init(fastly, version) {
   return fastly.setMainVCL(version, 'helix.vcl');
 }
 
-async function extensions(fastly, version) {
+async function extensions(fastly, version, vclOverride = {}) {
   const vclfile = path.resolve(__dirname, '../../layouts/fastly/extensions.vcl');
-  const content = include(vclfile);
+  let content;
+  if (vclOverride.extensions) {
+    // found a extensions.vcl override
+    content = synthetize(vclOverride.extensions, path.dirname(vclfile));
+  } else {
+    content = include(vclfile);
+  }
   return writevcl(fastly, version, content, 'extensions.vcl');
 }
 

src/publish.js

@@ -17,7 +17,7 @@ const vcl = require('./fastly/vcl');
 const dictionaries = require('./fastly/dictionaries');
 const redirects = require('./fastly/redirects');
 
-async function publish(configuration, service, token, version) {
+async function publish(configuration, service, token, version, vclOverrides = {}) {
   if (!(!!token && !!service)) {
     return {
       body: {
@@ -36,7 +36,7 @@ async function publish(configuration, service, token, version) {
       backends.init(fastly, version),
       backends.updatestrains(fastly, version, config.strains),
       vcl.init(fastly, version),
-      vcl.extensions(fastly, version),
+      vcl.extensions(fastly, version, vclOverrides),
       vcl.updatestrains(fastly, version, config.strains),
       redirects.updatestrains(fastly, version, config.strains),
       dictionaries.init(