I would like to start a new instance inside an Auto-Scaling group so the new instance will be 100% identical to other instances in this group.
In other words I want to do the same thing AWS does when scaling rules are triggered.
What API method I need to call to achieve this?
You can achieve this with the DescribeAutoScalingGroups API and the SetDesiredCapacity API.
Pseudocode:
Call DescribeAutoScalingGroups to get the current desired size of your group.
Call SetDesiredCapacity, setting DesiredCapacity = CurrentDesiredCapacity + 1
SetDesiredCapacity allows you to change the "desired capacity" of an AutoScaling group. If you increase the current desired capacity by 1, the AutoScaling Group will launch a new instance based on the AMI associated with your launch configuration. This is what scaling policies do within the bounds of your min/max capacity.
SetDesiredCapacity API Example: (from docs)
https://autoscaling.amazonaws.com/?Action=SetDesiredCapacity
&AutoScalingGroupName=my-asg
&HonorCooldown=false
&DesiredCapacity=2
&Version=2011-01-01
&AUTHPARAMS
set-desired-capacity CLI Example: (from docs)
aws autoscaling set-desired-capacity --auto-scaling-group-name my-auto-scaling-group --desired-capacity 2 --no-honor-cooldown
Reference:
AWS Documentation - Manual Scaling
API - SetDesiredCapacity
CLI - set-desired-capacity
Related
How can I make user defined instances from AWS CloudFormation?
Example:
Question: How many instances do you want?
Answer: 4
AWS CloudFormation should install 4 same instances.
You don't really need custom-resource for that. You can just create your instances as part of AWS::AutoScaling::AutoScalingGroup. ASG will create required number of instances once you set DesiredCapacity and MaxSize. So if you want 4 instances, you set these values to 4.
You have two options
Autoscaling Group - DesiredCapacity and MaxSize - AWS::AutoScaling::AutoScalingGroup
Spot fleet ( cost savings by 90%) - TargetCapacity - AWS::EC2::SpotFleet
I have setup code pipeline for end to end automatic deployment of revision on EC2 instances using cloudformation template, the deployment group is of type blue/green for codedploy.
But I dont understand how to keep the code deployment group in sync with newly created auto scaling group (green).
Do I have to create new lambda invoke action in pipeline after successful deployment to update the newly created auto scaling group name.
Unfortunately, CloudFormation does not support Blue/Green deployments for EC2 platform:
For blue/green deployments, AWS CloudFormation supports deployments on Lambda compute platforms only.
Support for ECS is very new.
To create deployment group for blue/green for EC2 platform you would have to create a custom resource in CloudFormation .
The custom resource would be based on a lambda function, and in that lambda function you would use create_deployment_group to define blue/green details for your EC2 instances. As part of this process, you will have an option to choose how to deal with AutoScaling group, e.g.
"greenFleetProvisioningOption": {
"action": "COPY_AUTO_SCALING_GROUP"
}
For creation of custom resource, crhelper by AWS is very useful.
Hope this helps and hope Blue/Green for EC2 will be supported by CloudFormation soon.
It is possible to configure an autoscaling group to use Launch Template instead of Launch Configuration. I want to use it because when I configure an autoscaling group using Launch Configuration I can not set mixed instances policy (ondemand + spot instances).
I have created launch template (name 'test') with such configuration:
AMI Ubuntu 16,
some security groups and IAM Role with EC2, AutoScaling and CodeDeploy full access
and all other settings in default *Not specified* state.
Launch Template ID lt-0e1111
Default Version Number 1
Launch Template Name test
Owner arn:aws:iam::11111111:user/itsp
Version 1 (Default)
Name test
Created by arn:aws:iam::179961111910:user/itsp
Description Not specified
Date Created February 8, 2019 at 12:47:54 AM UTC+3
AMI ID ami-0bf1924ed30c48a6a
Availability Zone Not specified
Security Groups Not specified
Instance Type t2.nano
Key pair name itsp
Security Group Ids sg-07e746cf0e4935b84,sg-0a45f7e6ac321614d,sg-27bf6d4b
Advanced Details:
Purchasing option Not specified
Spot request type Not specified
Spot interruption behavior Not specified
IAM Instance Profile Not specified
Stop - Hibernate behavior Not specified
Monitoring Not specified
EBS-optimized instance Not specified
Tenancy Host ID Not specified
RAM Disk ID Not specified
User Data Not specified
Elastic Inference Accelerator Not specified
Maximum Spot price Not specified
Spot expiry date -
Spot block duration Not specified
Shutdown behavior Not specified
Termination Protection Not specified
Placement Group Name Not specified
Tenancy Not specified
Tenancy Affinity Not specified
Kernel ID Not specified
Elastic Graphics Not specified
Then I am creating an AutoScaling group with that launch template. Here is my autoscaling group configuration:
Launch Template test
Launch Template Version 1
Launch Template Description -
Instance Types -
Spot Diversity 0
Optional On-Demand Base 0
On-Demand Percentage 0%
Desired Capacity 1
Min 1
Max 1
Availability Zone(s) eu-central-1a
Subnet(s) subnet-53075e38
Classic Load Balancers -
Target Groups -
Health Check Type EC2
Health Check Grace Period 300
Instance Protection -
Termination Policies Default
Suspended Processes -
Placement Groups -
Default Cooldown 300
Enabled Metrics -
Creation Time Fri Feb 08 00:50:16 GMT+300 2019
Service-Linked Role arn:aws:iam::11111111111:role/aws-service-role/autoscaling.amazonaws.com/AWSServiceRoleForAutoScaling
Such configuration appears to be set when I choose
*Fleet Composition - Adhere to the launch template
The launch template determines the instance type and purchase option (On-Demand or Spot).*
option and my lauch template configuration is described above.
So there are no spots in my autoscaling group.
Then I configure a CodeDeploy application 'Application' and DeploymentGroup 'DG_TEST' inside of it with such configuration:
Deployment type Blue/green
Service role ARN arn:aws:iam::11111111111111:role/CodeDeployRole
Deployment configuration CodeDeployDefault.AllAtOnce
Rollback enabled -
Environment configuration: Amazon EC2 Auto Scaling groups -> Name 'test'
Ok, after everything is set up I set desired instances count to 1 in my Autoscaling group and new on-demand instance spawns in my 'test' group.
I am now starting a blue-green deployment with AWS CLI command:
aws deploy create-deployment --application-name Application --s3-location bucket=codedeploybucket,key=application,bundleType=zip --deployment-group-name DG_TEST
And I can see new autoscaling group with same lauch template appears in my green fleet.
So we just checked all our services are working as expected.
Now I want to tweak my autoscaling group configuration a little to mix ondemand and spot instances in it:
Fleet Composition - Combine purchase options and instances
Choose a mix of On-Demand Instances and Spot Instances and multiple instance types. Spot Instances are automatically launched at the lowest price available.
Instance Types:
t2.nano (1vCPUs, 0.5GiB)
t2.small (1vCPUs, 2GiB)
t2.micro (1vCPUs, 1GiB)
Maximum Spot Price - Use default (recommended)
Spot Allocation Strategy - Diversify Spot Instances across your 2 lowest priced instance types per Availability Zone
Optional On-Demand Base - Designate the first 0 instances as On-Demand
On-Demand Percentage 50% On-Demand and 50% Spot
Desired Capacity 1
Min 1
Max 1
I save it and try same AWS CLI command
aws deploy create-deployment --application-name Application --s3-location bucket=codedeploybucket,key=application,bundleType=zip --deployment-group-name DG_TEST
And now I have my deployment failed with such comment:
The following validation error occurred: Valid requests must contain either LaunchTemplate, LaunchConfigurationName, InstanceId or MixedInstancesPolicy parameter. (Service: AmazonAutoScaling; Status Code: 400; Error Code: ValidationError; Request ID: 11111114-2b2b-11e9-93b7-11111111111)
Another strange thing is that if I configure my Launch Templae to use spots only:
Launch Template ID lt-00dc4c187d1111159
Default Version Number 1
Launch Template Name test2
Owner
arn:aws:iam::179961111910:user/itsp
Version 1 (Default)
Name test2
Created by arn:aws:iam::179961111910:user/itsp
Description Not specified
Date Created February 8, 2019 at 1:14:13 AM UTC+3
AMI ID ami-0bf1924ed30c48a6a
Availability Zone Not specified
Security Groups Not specified
Instance Type t2.micro
Key pair name itsp
Security Group Ids sg-0a45f7e6ac321614d,sg-07e746cf0e4935b84,sg-27bf6d4b
Advanced details
Purchasing option spot
Spot request type one-time
Spot interruption behavior Not specified
IAM Instance Profile CodeDeployRole (arn:aws:iam::1111111111:instance-profile/CodeDeployRole)
Stop - Hibernate behavior Not specified
Monitoring Not specified
EBS-optimized instance Not specified
Tenancy Host ID Not specified
RAM Disk ID Not specified
User Data Not specified
Elastic Inference Accelerator Not specified
Maximum Spot price Not specified
Spot expiry date -
Spot block duration Not specified
Shutdown behavior Not specified
Termination Protection Not specified
Placement Group Name Not specified
Tenancy Not specified
Tenancy Affinity Not specified
Kernel ID Not specified
Elastic Graphics Not specified
and use that option in my autoscaling group:
*Fleet Composition - Adhere to the launch template
The launch template determines the instance type and purchase option (On-Demand or Spot).*
Then after same deployment command I receive another error in CodeDeploy (failed deployment reason):
The IAM role arn:aws:iam::179966034910:role/CodeDeployRole does not give you permission to perform operations in the following AWS service: AmazonAutoScaling. Contact your AWS administrator if you need help. If you are an AWS administrator, you can grant permissions to your users or groups by creating IAM policies.
And that is definitely not the case because my role for CodeDeploy have full EC2, Autoscaling and CodeDeploy access.
Am I doing something wrong or that are bugs? How can I configure mixed autoscaling group (ondemand+spot instances) with codedeploy using launch templates? Thanks in advance!
I faced a similar issue when working with CodeDeploy and LaunchTemplates.
It looks like LaunchTemplates are still not supported by CodeDeploy.
We have to stick to LaunchConfigurations. They still don't support versioning, but for the most part, they are pretty much the same :/
I could't find where AWS has documented that little incompatibility issue when migrating LaunchConfigurations to LaunchTemplates... but could find here more info.
Sheers!
I want to create an ASG with only 1 instance initially.
I want all the instances of this ASG to be behind an ELB.
So I set load_balancers = ["${aws_elb.Production-Web-ELB.name}"] in the resource "aws_autoscaling_group" "ProductionWeb-ScalingGroup" .
Now, when I write the code for the resource "aws_elb" "Production-Web-ELB", and I set instances = ["${aws_autoscaling_group.ProductionWeb-ScalingGroup.*.id}"], I get the error...
Error configuring: 1 error(s) occurred:
* Cycle: aws_autoscaling_group.ProductionWeb-ScalingGroup, aws_elb.Production-Web-ELB
I understand that this error means that the one resource references the other in a circle. To check it I comment out the load_balancers = ["${aws_elb.Production-Web-ELB.name}"] part and terraform plan without any error.
So my question is: Am I unable using Terraform to create an ASG with an attached ELB and every EC2 that will spawn inside it will be automatically behind the ELB ?
Is there something from the documentation that I missed?
Is there a workaround?
You don't need to explicitly define the instances that will be associated with the ELB in terraform's ELB definition. By using the load_balancers argument, you're associating the ELB with the AutoScaling group, and AutoScaling will know to attach any instances that are created to that ELB when the AutoScaling group launches that instance.
Terraform isn't directly managing the state of the instances in this case -- AWS AutoScaling is, so their state likewise don't need to be defined in terraform beyond defining a launch configuration and associating it to the AutoScaling group.
To tell terraform to launch the AutoScaling group with a single instance, set your min_size argument to 1 and let your scaling policies handle the desired capacity from there. You could alternatively set desired_capacity to 1, but be wary of managing that state in terraform because it will set the desired_capacity to 1 every time you apply your plan.
I'm using Ansible to configure AWS Auto Scaling Groups (ASG). Looking at the ec2_asg_module options, there's none for enabling Monitoring in cloudWatch. However, that option can be enabled either form the AWS CLI or the AWS Console.
In the Console, it is labeled as "Group Metric Collection".
Keep in mind that I do not want to monitor the EC2 instances, but the Auto Scaling Group itself.
Thank you.
I submitted a PR last year to add 2 AWS modules : boto3 and boto3_wait.
These 2 modules allow you to interact with AWS API using boto3.
For instance, you could enable group metrics on the ASG by calling enable_metrics_collection method on AutoScaling service :
- name: Enable group metrics
boto3:
service: autoscaling
region: us-east-1
operation: enable_metrics_collection
parameters:
AutoScalingGroupName: my-auto-scaling-group
Granularity: 1Minute
Feel free to give the PR a thumbs-up if you like it! ;)