Add field to configure the reverse proxy

part of #596

src/reverseproxy.js

@@ -464,6 +464,12 @@ function writeAppNginxConfig(app, bundle, callback) {
     var sourceDir = path.resolve(__dirname, '..');
     var endpoint = 'app';
 
+    let frameAncestorsQuoted = null, robotsTxtQuoted = null, hiddenUpstreamHeaders = [];
+    const reverseProxyConfig = app.reverseProxyConfig || {}; // some of our code uses fake app objects
+    if (reverseProxyConfig.robotsTxt) robotsTxtQuoted = JSON.stringify(app.reverseProxyConfig.robotsTxt);
+    if (reverseProxyConfig.frameAncestors) frameAncestorsQuoted = app.reverseProxyConfig.frameAncestors.map(fa => `'${fa}'`).join(' ');
+    if (reverseProxyConfig.hideHeaders) hiddenUpstreamHeaders = app.reverseProxyConfig.hideHeaders;
+
     var data = {
         sourceDir: sourceDir,
         adminOrigin: settings.adminOrigin(),
@@ -473,7 +479,9 @@ function writeAppNginxConfig(app, bundle, callback) {
         endpoint: endpoint,
         certFilePath: bundle.certFilePath,
         keyFilePath: bundle.keyFilePath,
-        robotsTxtQuoted: app.robotsTxt ? JSON.stringify(app.robotsTxt) : null
+        robotsTxtQuoted,
+        frameAncestorsQuoted,
+        hiddenUpstreamHeaders
     };
     var nginxConf = ejs.render(NGINX_APPCONFIG_EJS, data);
 
@@ -502,7 +510,9 @@ function writeAppRedirectNginxConfig(app, fqdn, bundle, callback) {
         endpoint: 'redirect',
         certFilePath: bundle.certFilePath,
         keyFilePath: bundle.keyFilePath,
-        robotsTxtQuoted: null
+        robotsTxtQuoted: null,
+        frameAncestorsQuoted: null,
+        hiddenUpstreamHeaders: []
     };
     var nginxConf = ejs.render(NGINX_APPCONFIG_EJS, data);