tspecht · October 5, 2017 17:48
diff --git a/handler.js b/handler.js
 'use strict';

 var http = require('http');

 // Handler called on Origin Request event by CloudFront.
 // Copies the original URI header to a custom header field and rewrites the request to fetch /index.html as the application we are serving is a SPA.
 module.exports.metaTagOriginRequestRewriter = (event, context, callback) => {
  const request = event.Records[0].cf.request;
  request.headers["x-dubsmash-uri"] = [{key: "X-Dubsmash-URI", value: request.uri}];
  request.uri = "/index.html";
  callback(null, request);
 };

 // Helper function used to download content from a given URL.
 // As Lambda@Edge functions are very size & resource constrained we are not including request or something similar
 // in the bundle but rather use the old-school way of doing things.
 const downloadContent = function(url, callback) {
  http.get(url, function(res){
    var body = '';

    res.on('data', function(chunk){
      body += chunk.toString();
    });

    res.on('end', function(){
      callback(body, null);
    });
  }).on('error', function(e){
    callback(null, e);
  });
 };

 // Handler called on Origin Response event by CloudFront.
 // Checks if we need to customize based on the originally requested URI.
 // Fetches the metadata if necessary and injects it into the re-downloaded Origin document.
 // Note: This is needed since due to limitations on AWS side we are not allowed to alter the response body ...
 module.exports.metaTagOriginResponseRewriter = (event, context, callback) => {

  const request = event.Records[0].cf.request;
  const response = event.Records[0].cf.response;

  var uriMatches = /\/my_path\/([a-z0-9]{32})\/([a-z0-9]{32})/gi.exec(request.headers["x-dubsmash-uri"][0].value);
  if (uriMatches && uriMatches.length >= 3) {
    // We have a URI match, go and load some data!
    var url = 'http://my.service.com/' + uriMatches[2];
    const host = request.headers["host"][0].value;

    downloadContent(url, (body, error) => {
      if (error) {
        callback(null, response);
      } else {
        var video = JSON.parse(body);
        var metaTags = `<meta property="og:image" content="`+ video.thumbnail + `" /><meta property="og:video" content="` + video.video + `" />`;

        // Download the index file
        downloadContent("http://" + host + "/index.html", (indexBody, error) => {
          if (error) {
            callback(null, response);
          } else {
            var finishedBody = indexBody.replace(/(<head>)/gi, "<head>" + metaTags);

            // Generate the final response and call the callback
            const newResponse = {
              status: '200',
              statusDescription: 'OK',
              headers: response.headers,
              body: finishedBody,
            };
            callback(null, newResponse);
          }
        });
      }
    });
  } else {
    callback(null, response);
  }
 };
	'use strict';

	var http = require('http');

	// Handler called on Origin Request event by CloudFront.
	// Copies the original URI header to a custom header field and rewrites the request to fetch /index.html as the application we are serving is a SPA.
	module.exports.metaTagOriginRequestRewriter = (event, context, callback) => {
	const request = event.Records[0].cf.request;
	request.headers["x-dubsmash-uri"] = [{key: "X-Dubsmash-URI", value: request.uri}];
	request.uri = "/index.html";
	callback(null, request);
	};

	// Helper function used to download content from a given URL.
	// As Lambda@Edge functions are very size & resource constrained we are not including request or something similar
	// in the bundle but rather use the old-school way of doing things.
	const downloadContent = function(url, callback) {
	http.get(url, function(res){
	var body = '';

	res.on('data', function(chunk){
	body += chunk.toString();
	});

	res.on('end', function(){
	callback(body, null);
	});
	}).on('error', function(e){
	callback(null, e);
	});
	};

	// Handler called on Origin Response event by CloudFront.
	// Checks if we need to customize based on the originally requested URI.
	// Fetches the metadata if necessary and injects it into the re-downloaded Origin document.
	// Note: This is needed since due to limitations on AWS side we are not allowed to alter the response body ...
	module.exports.metaTagOriginResponseRewriter = (event, context, callback) => {

	const request = event.Records[0].cf.request;
	const response = event.Records[0].cf.response;

	var uriMatches = /\/my_path\/([a-z0-9]{32})\/([a-z0-9]{32})/gi.exec(request.headers["x-dubsmash-uri"][0].value);
	if (uriMatches && uriMatches.length >= 3) {
	// We have a URI match, go and load some data!
	var url = 'http://my.service.com/' + uriMatches[2];
	const host = request.headers["host"][0].value;

	downloadContent(url, (body, error) => {
	if (error) {
	callback(null, response);
	} else {
	var video = JSON.parse(body);
	var metaTags = `<meta property="og:image" content="`+ video.thumbnail + `" /><meta property="og:video" content="` + video.video + `" />`;

	// Download the index file
	downloadContent("http://" + host + "/index.html", (indexBody, error) => {
	if (error) {
	callback(null, response);
	} else {
	var finishedBody = indexBody.replace(/(<head>)/gi, "<head>" + metaTags);

	// Generate the final response and call the callback
	const newResponse = {
	status: '200',
	statusDescription: 'OK',
	headers: response.headers,
	body: finishedBody,
	};
	callback(null, newResponse);
	}
	});
	}
	});
	} else {
	callback(null, response);
	}
	};