Adds layergroupid header

Closes #311

lib/cartodb/controllers/named_maps.js

@@ -319,6 +319,7 @@ NamedMapsController.prototype.instantiateTemplate = function(req, res, template_
             }
             var tplhash = self.templateMaps.fingerPrint(template).substring(0,8);
             layergroup.layergroupid = cdbuser + '@' + tplhash + '@' + layergroup.layergroupid;
+            res.header('X-Layergroup-Id', layergroup.layergroupid);
 
             self.surrogateKeysCache.tag(res, new NamedMapsCacheEntry(cdbuser, template.name));
 

lib/cartodb/server_options.js

@@ -362,17 +362,22 @@ module.exports = function(redisPool) {
                 var cacheChannel = me.buildCacheChannel(dbName, result.affectedTables);
                 me.channelCache[cacheKey] = cacheChannel;
 
-                if (req.res && req.method == 'GET') {
-                    var res = req.res;
-                    var ttl = global.environment.varnish.layergroupTtl || 86400;
-                    res.header('Cache-Control', 'public,max-age='+ttl+',must-revalidate');
-                    res.header('Last-Modified', (new Date()).toUTCString());
-                    res.header('X-Cache-Channel', cacheChannel);
-                }
-
                 // last update for layergroup cache buster
                 response.layergroupid = response.layergroupid + ':' + result.lastUpdatedTime;
                 response.last_updated = new Date(result.lastUpdatedTime).toISOString();
+
+                var res = req.res;
+                if (res) {
+                    if (req.method === 'GET') {
+                        var ttl = global.environment.varnish.layergroupTtl || 86400;
+                        res.header('Cache-Control', 'public,max-age='+ttl+',must-revalidate');
+                        res.header('Last-Modified', (new Date()).toUTCString());
+                        res.header('X-Cache-Channel', cacheChannel);
+                    }
+
+                    res.header('X-Layergroup-Id', response.layergroupid);
+                }
+
                 return null;
             },
             function finish(err) {

test/acceptance/multilayer.js

@@ -69,6 +69,7 @@ suite(suiteName, function() {
               assert.equal(parsedBody.last_updated, expected_last_updated);
               if ( expected_token ) {
                 assert.equal(parsedBody.layergroupid, expected_token + ':' + expected_last_updated_epoch);
+                assert.equal(res.headers['x-layergroup-id'], parsedBody.layergroupid);
               }
               else expected_token = parsedBody.layergroupid.split(':')[0];
               next(null, res);
@@ -1011,6 +1012,7 @@ suite(suiteName, function() {
               var parsedBody = JSON.parse(res.body);
               if ( expected_token ) {
                 assert.equal(parsedBody.layergroupid, expected_token + ':' + expected_last_updated_epoch);
+                assert.equal(res.headers['x-layergroup-id'], parsedBody.layergroupid);
               }
               else {
                 var token_components = parsedBody.layergroupid.split(':');
@@ -1091,6 +1093,7 @@ suite(suiteName, function() {
           var parsedBody = JSON.parse(res.body);
           if ( expected_token ) {
             assert.equal(parsedBody.layergroupid, expected_token + ':' + expected_last_updated_epoch);
+            assert.equal(res.headers['x-layergroup-id'], parsedBody.layergroupid);
           }
           else {
             var token_components = parsedBody.layergroupid.split(':');

test/acceptance/multilayer_server.js

@@ -108,6 +108,7 @@ describe('tests from old api translated to multilayer', function() {
             function(res) {
                 var parsed = JSON.parse(res.body);
                 assert.ok(parsed.layergroupid);
+                assert.equal(res.headers['x-layergroup-id'], parsed.layergroupid);
                 done();
             }
         );
@@ -128,6 +129,7 @@ describe('tests from old api translated to multilayer', function() {
             function(res) {
                 var parsed = JSON.parse(res.body);
                 assert.ok(parsed.layergroupid);
+                assert.equal(res.headers['x-layergroup-id'], parsed.layergroupid);
 
                 global.environment.postgres.host = backupDBHost;
                 done();
@@ -150,6 +152,7 @@ describe('tests from old api translated to multilayer', function() {
             function(res) {
                 var parsed = JSON.parse(res.body);
                 assert.ok(parsed.layergroupid);
+                assert.equal(res.headers['x-layergroup-id'], parsed.layergroupid);
 
                 global.environment.postgres_auth_pass = backupDBPass;
                 done();
@@ -246,6 +249,8 @@ describe('tests from old api translated to multilayer', function() {
                 assert.ok(res.headers.hasOwnProperty('x-cache-channel'));
                 assert.equal(res.headers['x-cache-channel'], expectedCacheChannel);
 
+                assert.equal(res.headers['x-layergroup-id'], parsed.layergroupid);
+
                 done();
             }
         );

test/acceptance/templates.js

@@ -1321,6 +1321,7 @@ describe('template_api', function() {
           layergroupid = parsed.layergroupid;
           assert.ok(layergroupid.match(/^localhost@/),
             "Returned layergroupid does not start with signer name: " + layergroupid);
+          assert.equal(res.headers['x-layergroup-id'], parsed.layergroupid);
           assert.ok(parsed.hasOwnProperty('last_updated'),
             "Missing 'last_updated' from response body: " + res.body);
           // TODO: check value of last_updated ?