Modifying an AWS Cloud Formation Template

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Modifying an AWS Cloud Formation Template

Now, since the template has already been created, we will modify it, to enable you to launch a new environment with the custom AMI. By doing so, you will have multiple instances spanned across multiple Availability Zones. Here is the procedure to launch a new stack with a modified template:

  • Open the template that you’ve just created using CloudFormer.
  • Update the CloudDistribution group to include DistributionConfig and the Loggingportion.
“distd18k4jybr69gw2cloudfrontnet” : { “Type” : “AWS::CloudFront::Distribution”, “Properties” : { “DistributionConfig” : { “S3Origin” : { “DNSName”: “webapplication.s3.amazonaws.com” }, “Enabled” : “true”, “Logging” : { “Bucket” : “webapplication.s3.amazonaws.com”, “Prefix” : “webapp-logging/” } } } },

In the Auto-Scaling group, update the “Max Size”, “Min Size”, and “Desired Capacity” to 2. 

“asgMyAutoScalingGroup”: { “Type”: “AWS::AutoScaling::AutoScalingGroup”, “Properties”: { “AvailabilityZones”: [ "us-east-1b", "us-east-1c" ], “Cooldown”: “300″, “DesiredCapacity”: “2″, “MaxSize”: “2″, “MinSize”: “2″, “LaunchConfigurationName”: { “Ref”: “lcMyLC” }, “LoadBalancerNames”: [ { "Ref": "elbMyLB" } ] } },
  •  
  • Update the Image ID in the “Launch Configuration” group to the custom AMI that you had created in the Creating a Custom AMI section.

Note: Your AMI ID will be different from the one you see below.

“lcMyLC”: { “Type”: “AWS::AutoScaling::LaunchConfiguration”, “Properties”: { “ImageId”: “ami-576ca43e”, “InstanceType”: “t1.micro”, “KeyName”: “mykeypair”, “SecurityGroups”: [ { "Ref": "sgwebappsecuritygroup" } ] } },
  • Now, update the following parameters in the Database group:
    • Update “DBName” to mydb.
    • Update “MasterUserPassword” to the master password you specifed in the Adding Amazon RDS section. 
“rdsawsworkshop”: { “Type”: “AWS::RDS::DBInstance”, “Properties”: { “AllocatedStorage”: “5″, “BackupRetentionPeriod”: “1″, “DBInstanceClass”: “db.m1.small”, “DBName”: “mydb”, “DBParameterGroupName”: “default.mysql5.1″, “Engine”: “mysql”, “EngineVersion”: “5.1.57″, “MasterUsername”: “awsuser”, “MasterUserPassword”: “mypassword”, “Port”: “3306″, “PreferredBackupWindow”: “08:30-09:00″, “PreferredMaintenanceWindow”: “fri:03:30-fri:04:00″, “MultiAZ”: “true”, “DBSecurityGroups”: [ { "Ref": "dbsgmydbsecuritygroup" } ] } },