VPC Method

   var createVPC = function() {
       AWSService.createVpc().then(function(res) {
           $log.info('VPC Started');
           resourceID = vpc_ = res.Vpc.VpcId;
           tag = {
               Key: 'Name',
               Value: 'Demo-VPC'
           };
           AWSService.createTags(resourceID, tag);
           AWSService.modifyVpcAttribute(vpc_); // Enable DNS hostname
           AWSService.createInternetGateway().then(function(res) {
               resourceID = igw_ = res.InternetGateway.InternetGatewayId;
               tag = {
                   Key: 'Name',
                   Value: 'Demo-InternetGateway'
               };
               AWSService.createTags(resourceID, tag);
               AWSService.attachInternetGateway(vpc_, igw_).then(function() {
                   AWSService.createSubnet(vpc_).then(function(res) {
                       resourceID = subnet_ = res.Subnet.SubnetId;
                       tag = {
                           Key: 'Name',
                           Value: 'Demo-Subnet'
                       };
                       AWSService.createTags(resourceID, tag);
                       AWSService.createRouteTable(vpc_).then(function(res) {
                           resourceID = rtb_ = res.RouteTable.RouteTableId;
                           tag = {
                               Key: 'Name',
                               Value: 'Demo-RouteTable'
                           };
                           AWSService.createTags(resourceID, tag);
                           AWSService.associateRouteTable(rtb_, subnet_).then(function() {
                               AWSService.createRoute(rtb_, igw_).then(function() {
                                   AWSService.createSecurityGroup(vpc_).then(function(res) {
                                       resourceID = sg_ = res.GroupId;
                                       tag = {
                                           Key: 'Name',
                                           Value: 'Demo-SecurityGroup'
                                       };
                                       AWSService.createTags(resourceID, tag);
                                       AWSService.authorizeSecurityGroupIngress(sg_).then(function(res) {
                                           $log.info('Now Creating EC2 instance', res);
                                           createInstance();
                                       }, function(err) {
                                           $log.error('error in authorizeSecurityGroupIngress', err);
                                       });
                                   }, function(err) {
                                       $log.error('error in createSecurityGroup', err);
                                   }, function(notify) {
                                       vm.message = notify;
                                   }).finally(function() {
                                       $log.info('VPC Created');
                                       vm.message = 'VPC created successfully.';
                                   });
                               }, function(err) {
                                   $log.error('error in createRoute', err);
                               }, function(notify) {
                                   vm.message = notify;
                               });
                           }, function(err) {
                               $log.error('error in associateRouteTable', err);
                           }, function(notify) {
                               vm.message = notify;
                           });
                       }, function(err) {
                           $log.error('error in createRouteTable', err);
                       }, function(notify) {
                           vm.message = notify;
                       });
                   }, function(err) {
                       $log.error('error in createSubnet', err);
                   }, function(notify) {
                       vm.message = notify;
                   });
               }, function(err) {
                   $log.error('error in attachInternetGateway', err);
               }, function(notify) {
                   vm.message = notify;
               });
           }, function(err) {
               $log.error('error in createInternetGateway', err);
           }, function(notify) {
               vm.message = notify;
           });
       }, function(err) {
           $log.error('error in createVpc', err);
       }, function(notify) {
           vm.message = notify;
       });
   };