Auto Scaling

Floci implements the EC2 Auto Scaling API — stored-state management for launch configurations, auto scaling groups, lifecycle hooks, and scaling policies, plus a real capacity reconciler that launches and terminates EC2 instances to maintain desired capacity.

Protocol: Query — POST / with Action= form parameter, credential scope autoscaling

ARN formats:

arn:aws:autoscaling:<region>:<account>:autoScalingGroup:<uuid>:autoScalingGroupName/<name>
arn:aws:autoscaling:<region>:<account>:launchConfiguration:<uuid>:launchConfigurationName/<name>
arn:aws:autoscaling:<region>:<account>:scalingPolicy:<uuid>:autoScalingGroupName/<group>/policyName/<name>

Supported Operations (33 total)

Launch Configurations

Operation	Notes
`CreateLaunchConfiguration`	Stores template: `ImageId`, `InstanceType`, `KeyName`, `SecurityGroups`, `UserData`, `IamInstanceProfile`
`DescribeLaunchConfigurations`	Filtered by name list; returns all if no filter
`DeleteLaunchConfiguration`	Removes the named launch configuration

Auto Scaling Groups

Operation	Notes
`CreateAutoScalingGroup`	Creates a group with min/max/desired capacity, AZs, tags; starts capacity reconciliation loop
`DescribeAutoScalingGroups`	Filtered by name list; returns all if no filter; includes current instance list with lifecycle state
`UpdateAutoScalingGroup`	Updates capacity bounds, cooldown, launch configuration, AZs
`DeleteAutoScalingGroup`	`ForceDelete=true` terminates all instances before deletion

Instance Management

Operation	Notes
`DescribeAutoScalingInstances`	Returns all ASG-tracked instances with lifecycle state and health status
`SetDesiredCapacity`	Updates desired count; reconciler handles scale-out / scale-in within 10 s
`AttachInstances`	Attaches existing EC2 instances to a group; sets lifecycle state to `InService`
`DetachInstances`	Detaches instances from a group; optionally decrements desired capacity
`TerminateInstanceInAutoScalingGroup`	Terminates a specific instance; optionally decrements desired capacity

Load Balancer Attachment

Operation	Notes
`AttachLoadBalancerTargetGroups`	Attaches ELB v2 target group ARNs; new instances auto-registered on InService
`DetachLoadBalancerTargetGroups`	Detaches target groups; instances deregistered
`DescribeLoadBalancerTargetGroups`	Lists target groups attached to a group
`AttachLoadBalancers`	Classic ELB attachment (stored; no ELB v1 routing)
`DetachLoadBalancers`	Classic ELB detachment
`DescribeLoadBalancers`	Lists classic ELBs attached to a group

Lifecycle Hooks

Operation	Notes
`PutLifecycleHook`	Creates or updates a hook: `LifecycleTransition`, `DefaultResult`, `HeartbeatTimeout`
`DescribeLifecycleHooks`	Lists hooks for a group
`DeleteLifecycleHook`	Removes a hook
`CompleteLifecycleAction`	Signals `CONTINUE` or `ABANDON` for a pending lifecycle action
`RecordLifecycleActionHeartbeat`	Extends the heartbeat timeout for an in-progress lifecycle action

Scaling Policies

Operation	Notes
`PutScalingPolicy`	Creates or updates a policy: `SimpleScaling`, `AdjustmentType`, `ScalingAdjustment`, `Cooldown`
`DescribePolicies`	Lists policies filtered by group or policy name
`DeletePolicy`	Removes a scaling policy

Activities

Operation	Notes
`DescribeScalingActivities`	Returns the activity log for a group; activities recorded on scale-out and scale-in events

Metadata

Operation	Notes
`DescribeTerminationPolicyTypes`	Returns the standard termination policy names
`DescribeAccountLimits`	Returns max group / config / instance limits
`DescribeLifecycleHookTypes`	Returns `autoscaling:EC2_INSTANCE_LAUNCHING` and `autoscaling:EC2_INSTANCE_TERMINATING`
`DescribeAdjustmentTypes`	Returns the four standard adjustment types
`DescribeMetricCollectionTypes`	Returns standard metric and granularity names
`DescribeAutoScalingNotificationTypes`	Returns all notification type names

Capacity Reconciler (Phase 2)

Floci runs a background reconciler (10 s fixed rate) that keeps each group's InService instance count aligned with DesiredCapacity:

Scale-out: calls RunInstances with the group's launch configuration; new instances are tracked as Pending until the EC2 state transitions to running, at which point they move to InService and are registered with all attached ELB v2 target groups.
Scale-in: selects InService instances not protected from scale-in, deregisters them from target groups, then calls TerminateInstances.
Activity records are written on each scale-out and scale-in event.

Configuration

Variable	Default	Description
`FLOCI_SERVICES_AUTOSCALING_ENABLED`	`true`	Enable or disable the service

Usage Example

# Create a launch configuration
aws autoscaling create-launch-configuration \
  --launch-configuration-name my-lc \
  --image-id ami-12345678 \
  --instance-type t3.micro

# Create a group targeting desired=2
aws autoscaling create-auto-scaling-group \
  --auto-scaling-group-name my-asg \
  --launch-configuration-name my-lc \
  --min-size 1 \
  --max-size 5 \
  --desired-capacity 2 \
  --availability-zones us-east-1a

# Attach an ELB v2 target group
aws autoscaling attach-load-balancer-target-groups \
  --auto-scaling-group-name my-asg \
  --target-group-arns arn:aws:elasticloadbalancing:us-east-1:000000000000:targetgroup/my-tg/abc123

# Watch instances appear
aws autoscaling describe-auto-scaling-groups \
  --auto-scaling-group-names my-asg

# Scale out
aws autoscaling set-desired-capacity \
  --auto-scaling-group-name my-asg \
  --desired-capacity 3