title: How to add a RDS instance to a VPC using aws cloudformation
body: <p>When I launch a RDS instance manually I'm able to assign what VPC I want it to be part of. I'm trying to create a stack using AWS cloudformation, however I do not see an API to be able to do that. I can create my VPC in the stack and then reference it for security groups both EC2 and DB security groups and they both end up been part of the VPC however the RDS instance itself does not. Is there a way to assign the VPC to the RDS instance? </p>
  
  <p>Below is my template:</p>
  
  <pre><code>{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Metadata": {
      "AWS::CloudFormation::Designer": {
        "30e03bfc-b61a-4d6c-89db-1b62b258a305": {
          "size": {
            "width": 80,
            "height": 80
          },
          "position": {
            "x": 700,
            "y": 170
          },
          "z": 0,
          "embeds": []
        }
      }
    },
  
    "Parameters": {
  
      "DBPreferredBkupWindow": {
        "Description"                 : "The daily time range (in UTC) during which automated backups are created, ideally off peak-hours.",
        "Type"                        : "String",
        "MinLength"                   : "1",
        "MaxLength"                   : "11",
        "AllowedPattern"              : "\\d[0-23]:\\d[0-59]-\\d[0-23]:\\d[0-59]",
        "Default"                     : "01:00-02:00"
      }
    },
  
    "Resources": {
  
      "VPC": {
        "Type": "AWS::EC2::VPC",
        "Properties": {
          "CidrBlock"                 : "172.16.0.0/16",
          "EnableDnsSupport"          : true
        }
      },
  
      "DB": {
        "Type": "AWS::RDS::DBInstance",
        "Properties": {
          "DBName"                    : "ems",
          "Engine"                    : "postgres",
          "EngineVersion"             : "9.4.7",
          "DBInstanceClass"           : "db.t1.micro",
          "DBInstanceIdentifier"      : "rltdb",
          "MasterUsername"            : "pgadmin",
          "MasterUserPassword"        : "pgadmin1",
          "AllocatedStorage"          : "100",
          "Iops"                      : "1000",
          "BackupRetentionPeriod"     : "7",
          "PreferredBackupWindow"     : { "Ref" : "DBPreferredBkupWindow" },
          "MultiAZ"                   : true,
          "PubliclyAccessible"        : false,
          "AutoMinorVersionUpgrade"   : false,
          "VPCSecurityGroups"         : [{ "Ref" : "SecurityGroup" } ]
        },
  
        "Metadata": {
          "AWS::CloudFormation::Designer": {
            "id": "30e03bfc-b61a-4d6c-89db-1b62b258a305"
          }
        }
      },
  
      "DBSecurityGroup": {
        "Type": "AWS::RDS::DBSecurityGroup",
        "Properties": {
          "EC2VpcId"                  : { "Ref" : "VPC" },
          "DBSecurityGroupIngress"    : { "EC2SecurityGroupName": { "Ref": "SecurityGroup"} },
          "GroupDescription"          : "Database Access"
        }
      },
  
      "SecurityGroup" : {
        "Type" : "AWS::EC2::SecurityGroup",
        "Properties" : {
          "VpcId"                     : { "Ref" : "VPC" },
          "GroupDescription"          : "Enable database access for application",
          "SecurityGroupIngress"      : [
            {"IpProtocol" : "tcp", "FromPort" : "5432", "ToPort" : "5432", "CidrIp" : "0.0.0.0/0"}
          ]
        }
      }
    }
  }
  </code></pre>