One of the primary benefits of a cloud computing environment is the increased automation. The Provisioning Service is perhaps the core mechanism to deliver this. To better understand the kinds of things we might orchestrate, take a look at the following template. You'll notice that it takes on the same format as Amazon's CloudFormation. This example launches a load balancer as part of our LB-aaS solution for a Eucalyptus cloud:
{
"ToughTemplateFormatVersion" : "2011-03-01",
"Description" : "Launch Load Balancer instance and install LB software.",
"Parameters" : {
"AvailabilityZone" : {
"Description" : "AvaialbilityZone in which an instance should be created",
"Type" : "String"
},
"AccountId" : {
"Description" : "Account Id",
"Type" : "String"
},
"LoadBalancerName" : {
"Description" : "Load Balancer Name",
"Type" : "String"
}
},
"Mappings" : {
"AvailabilityZoneMap" : {
"msicluster" : {
"SecurityGroups" : "default",
"ImageId" : "emi-FF070BFE",
"KeyName" : "rarora",
"EKI" : "eki-3A4A0D5A",
"ERI" : "eri-B2C7101A",
"InstanceType" : "c1.medium",
"UserData" : "80"
}
}
},
"Resources" : {
"LoadBalancerLaunchConfig": {
"Type": "TOUGH::LaunchConfiguration",
"Properties": {
"AccountId" : { "Ref" : "AccountId" },
"SecurityGroups" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "SecurityGroups" ]},
"ImageId" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "ImageId" ]},
"KeyName" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "KeyName" ]},
"InstanceType" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "InstanceType" ]},
"EKI" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "EKI" ]},
"ERI" : { "Fn::FindInMap" : [ "AvailabilityZoneMap", { "Ref" : "AvailabilityZone" }, "ERI" ]}
}
},
"LoadBalancerInstance" : {
"Type" : "TOUGH::EUCA::LaunchInstance",
"Properties" : {
"AccountId" : { "Ref" : "AccountId" },
"AvailabilityZone": { "Ref" : "AvailabilityZone" },
"LaunchConfig" : { "Ref" : "LoadBalancerLaunchConfig" },
"Setup" : {
}
}
},
"RegisterLoadBalancerInstance" : {
"Type" : "TOUGH::ElasticLoadBalancing::RegisterLoadBalancerInstance",
"Properties" : {
"AccountId" : { "Ref" : "AccountId" },
"LoadBalancerName" : { "Ref" : "LoadBalancerName" },
"Instance" : { "Ref" : "LoadBalancerInstance" }
}
},
"Setup" :{
"Type" : "TOUGH::EUCA::Parallel",
"Operations" : {
"TrackLoadBalancerInstance" : {
"Type" : "TOUGH::EUCA::TrackInstance",
"Name" : "LoadBalancerInstance",
"Properties" : {
"AccountId" : { "Ref" : "AccountId" },
"InstanceId" : { "Fn::GetAtt" : [ "LoadBalancerInstance", "InstanceId" ] }
}
},
"InstalLoadBalancerSoftware" : {
"Type" : "TOUGH::ElasticLoadBalancing::InstallLoadBalancerSoftware",
"Properties" : {
"AccountId" : { "Ref" : "AccountId" },
"IP" : { "Fn::GetAtt" : [ "LoadBalancerInstance", "PublicIp" ] }
}
}
}
}
},
"Outputs" : {
"PublicIP" : {
"Description" : "PublicIP address of the LoadBalancer",
"Value" : { "Fn::GetAtt" : [ "LoadBalancerInstance", "PublicIp" ] }
}
}
}
The JSON format can be a bit difficult to read if you're not familiar with it. Amazon and others now have UI's that facilitate the creation of the templates. In this example, there are a few items worth noting:
1. The template accepts input variables and returns information at the end of execution
2. The orchestration automates a series of tasks (launches a bare image, installs LB software, tracks the progress, configures the software, registers the newly launched instance, etc.)
3. The templates treat the cloud concepts (availability zones, cloud services, etc.) as first-order concepts in the syntax.
Keep in mind that the orchestration scripts can be multiple levels deep. This example was a simple one just to launch a load balancer. A more complicated orchestration would initiate multiple orchestration templates.
In the coming months, we'll be releasing a series of templates designed to orchestrate the provisioning of many common applications. The provisioning templates will fully leverage the power of the cloud (auto scale, auto recover, auto-snapshot, auto balance, etc.)
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