autoscaling 3.3 design

Table of Contents Overview Tracking Out of Scope Feature Dependencies Related Features Implementation Summary Analysis Open Issues Design Entities Service Impact Supported Operations Integration Areas IAM Eucalyptus Extensions IAM Administrative Functionality Listing Resources Deleting Resources Updating Resources Configuration Upgrade Packaging Documentation Security Testing References

Overview

This design covers our implementation of AWS Auto Scaling.

Tracking

Status	Draft
Updated	2012/12/19	Initial document, focus is preparation for Sprint 1
Updated	2013/01/28	Updated for Sprint 2 functionality (which was previously for Sprint 1)
Updated	2013/02/01	Updated with Sprint 2 final details

Out of Scope

Implementation of items related to features that we do not support are out of scope. These features are:

• IAM Roles
• Placement groups
• Spot Instances
• SNS
• VPC

Feature Dependencies

• EC2 - Verifying metadata, managing instances, tagging
• ELB - health check type

Related Features

This feature relates to the following features in this release:

• EC2 - Tagging / Filtering
• EC2 - Instance health checking
• CloudWatch
• ElasticLoadBalancing

Implementation Summary

Item	Value	Notes
Version	2011-01-01	Version of AutoScaling API supported
DB	eucalyptus_autoscaling
Source modules	scaling	Contents under com.eucalyptus.scaling package
	scaling-common	Contents under com.eucalyptus.scaling.common package
Service class	AutoScalingService
Component ID class	AutoScaling
Service type name	autoscaling
Service URIs	/services/AutoScaling	SOAP / Query API
	/internal/AutoScaling	SOAP / Query API
Eucarc variable name	AWS_AUTO_SCALING_URL
Properties prefix	autoscaling

Analysis

Open Issues

• Are we implementing metrics operations? ( DescribeMetricCollectionTypes, DisableMetricsCollection, EnableMetricsCollection )
• Are we supporting CW of auto scaling?
• Are we supporting "pagination" for describe operations?
• Where are ARNs supported instead of names? (are ARNs supported for the policy name in PutScalingPolicy?)

Design

Entities

The following entities will be added:

• Launch configuration
• Auto scaling group
• Auto scaling policy

Service Impact

New SOAP / Query API user facing services are added.

Supported Operations

For more information on administrative support by operation, see Administrative Functionality below.

Operation	Policy Enforced	Admin Enabled	Notes
CreateAutoScalingGroup	Y	Placement group, VPC Zone Identifier not supported.
CreateLaunchConfiguration	Y	Spot Price, IAM Instance Profile, EBS Optimized not supported.
DeleteAutoScalingGroup	Y	Y
DeleteLaunchConfiguration	Y	Y
DeletePolicy	Y	Y
DescribeAdjustmentTypes	Y
DescribeAutoScalingGroups	Y	Y
DescribeLaunchConfigurations	Y	Y
DescribePolicies	Y	Y
DescribeTerminationPolicyTypes	Y
ExecutePolicy	Y	Y
PutScalingPolicy	Y
SetDesiredCapacity	Y	Y
UpdateAutoScalingGroup	Y	Y	Placement group, VPC Zone Identifier not supported.

Integration Areas

IAM

Item	Value	Notes
Vendor	autoscaling	Prefix for actions, e.g. autoscaling:DescribeLaunchConfigurations
Resources	launchconfiguration
	autoscalinggroup
	scalingpolicy
Actions	autoscaling:*	We will permit use in policy of any actions from the supported API version
Quotas	autoscaling:quota-launchconfigurationnumber
	autoscaling:quota-autoscalinggroupnumber
	autoscaling:quota-scalingpolicynumber

The ARN of an Auto Scaling resource has the form:

  arn:aws:autoscaling::<account id>:<resource type>/<resource id>:[<name>/<value>]+

An example policy for service access:

    {
       "Statement":[{
          "Effect":"Allow",
          "Action":"autoscaling:*",
          "Resource":"*"
       }]
    }

Eucalyptus Extensions

IAM

Support for quotas and resource (see above)

An example policy for limiting auto scaling groups:

    {
      "Statement":[{
        "Effect":"Limit",
        "Action":"autoscaling:createautoscalinggroup",
        "Resource":"*",
        "Condition":{
          "NumericLessThanEquals":{
            "autoscaling:quota-autoscalinggroupnumber":"2",
          }
        }
      }]
    }

Administrative Functionality

We will extend the standard functionality for administrative purposes.

Listing Resources

The following operations will support listing of all accounts/users item:

• DescribeLaunchConfigurations
• DescribeAutoScalingGroups
• DescribePolicies

To enable this the parameter verbose is passed as a name selector.

Deleting Resources

The following operations will support administrative deletion of resources:

• DeleteLaunchConfiguration
• DeleteAutoScalingGroup
• DeletePolicy

For administrative deletion the ARN of the resource must be used (not the simple name), e.g.:

  arn:aws:autoscaling::013765657871:launchConfiguration:6789b01a-a9c9-489f-9d24-ed39533fca61:launchConfigurationName/Test

Updating Resources

The following operations will support administrative update of resources:

• ExecutePolicy
• SetDesiredCapacity
• UpdateAutoScalingGroup

For administrative deletion the ARN of the resource must be used (not the simple name)

Configuration

No configuration properties noted.

Upgrade

No upgrade impact noted.

Packaging

No specific packaging requirements.

Documentation

Administrative functionality should be documented.

Security

Use of ARN in place of simple name adds risk of permitting deletion of other accounts resources.

Testing

No specific test cases noted.

References

• AutoScaling and IAM (amazonwebservices.com)

tag:rls-3.3