I am currently creating a CloudFormation template. When making an ec2 instance, I want to make it t2.nano and T2Unlimited. From Ec2::Instance doc I managed to find InstanceType property. However, I cannot find T2Unlimited.
Question
In cloud formation template, is it possible to make certain ec2 instance resource T2Unlimited?
Use the "CreditSpecification" : CreditSpecification property of CloudFormation EC2 Resource. The value will be either: standard or unlimited
From Lakhan's answer, I managed to come up with following property configuration, which worked correctly:
CreditSpecification:
CPUCredits: unlimited
(Needed the CPUCredits field to make it work correctly.)
Related
I've currently been trying to follow the AWS Workshops guide for the 'Amazon Labs for PostgreSQL'.
The first prerequisite is to create a Cloudformation template using the template provided (see here: https://catalog.us-east-1.prod.workshops.aws/workshops/098605dc-8eee-4e84-85e9-c5c6c9e43de2/en-US/1-prereq/i-need-to-deploy-lab-environment-manually/setup-with-aurora-pg)
However, the creation process consistently ends up failing. The two images above show the errors I'm receiving.
I know that template creation should work (and has previously) given that the role I'm using has PowerUser rights so CF is possible for myself. Are there any other reasons as to why this failure could be occurring?
in your template aupglabsGDBstack resource attribute
Properties.OwnerArn is a string that says Specify Cloud9 owner ARN instead of an actual arn of the cloud9 owner. Make sure to add a valid Arn:
aupglabsGDBstack:
Properties:
OwnerArn: <insert-valid-arn>
I’m creating a generic stack template using CloudFormation, and I’ve hit a rather annoying circular reference.
Overall Requirements:
I want to be able to provision (a lot of other things, but mainly) an ECS Cluster Service that auto-scales using capacity providers, the capacity providers are using auto-scaling groups, and the auto scaling groups are using a launch template.
I don’t want static resource names. This causes issues if a resource has to be re-created due to an update and that particular resource has to have a unique name.
Problem:
Without the launch template “knowing the cluster name” (via UserData) the service tasks get stuck in a PROVISIONING state.
So we have the first dependency chain:
Launch Template <- Cluster (Name)
But the Cluster has a dependency chain of:
Cluster <- Capacity Provider <- AutoScalingGroup <- Launch Template
Thus, we have a circular reference: Cluster <-> Launch Template
——
One way I can think of resolving this is to add a suffix to another resource’s name (one that lives outside of this dependency chain, e.g., the target group) as the Cluster’s name; in that way, it is not static but also removes the circular reference.
My question is: is there a better way?
It feels like there should be a resource that the cluster can subscribe to and the ec2 instance can publish to, which would remove the circular dependency as well as the need to assign resource names.
There is no such resource to break the dependency and the cluster name must be pre-defined. This has already been recognized as a problem and its part of open github issue:
[ECS] Full support for Capacity Providers in CloudFormation.
One of the issues noted is:
Break circular dependency so that unnamed clusters can be created
At the moment one work around noted is to partially predefine the name, e.g.:
ECSCluster:
Type: AWS::ECS::Cluster
Properties:
ClusterName: !Sub ${AWS::StackName}-ECSCluster
LaunchConfiguration:
Type: AWS::AutoScaling::LaunchConfiguration
Properties:
UserData:
Fn::Base64: !Sub |
#!/bin/bash
echo ECS_CLUSTER=${AWS::StackName}-ECSCluster >> /etc/ecs/ecs.config
Alternatively, one could try to solve that by development of some custom resource that would be in the form of a lambda function. So you could probably create your unnamed cluster with launch template (LT) that has some dummy name for cluster. Then once the cluster is running, you would use the custom resource to create new version of LT with updated cluster name and refresh your auto-scaling group to use the new LT version. But I'm not sure if this would work. Nevertheless, its something that can be considered at least.
Sharing an update from the GitHub issue. The circular dependency has been broken by introducing a new resource: Cluster Capacity Provider Associations.
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-clustercapacityproviderassociations.html
To use it in my example, you:
Create Cluster (without specifying name)
Create Launch Template (using Ref to get cluster name)
Create Auto Scaling Group(s)
Create Capacity Provider(s)
Create Cluster Capacity Provider Associations <- This is new!
The one gotcha is that you have to wait for the new association to be created before you can create a service on the cluster. So be sure that your service "DependsOn" these associations!
As per the AWS Cloudformation documentation
it is mentioned that Cloudformation automatically provides stack-level tags to resources.
aws:cloudformation:logical-id
aws:cloudformation:stack-id
aws:cloudformation:stack-name
I could see that for resources like EC2, S3, etc.
But when it comes to EMR I couldn’t see those tags. I need aws:cloudformation:stack-id tag value, so that I can later identify stackId without any hustle.
Isn’t it supported for EMR?
If not what could be workaround? I need to add CF stackId using which I can easily identify the stack for other use.
Note: aws cloudformation describe-stack-resources --physical-resource-id j-XXXXXXXXXXX this is not an option to get stackId because of not having enough IAM politics.
How I'm creating EMR cluster: I have one lambda which invokes CloudFormation using boto3, which then created the cluster.
I checked that on my EMR cluster and CloudFormation. You are correct. Tags are no where to be seen.
Could be oversight on AWS part, as they explicitly write in the docs that only EBS volumes don't have such tags:
All stack-level tags, including automatically created tags, are propagated to resources that AWS CloudFormation supports. Currently, tags are not propagated to Amazon EBS volumes that are created from block device mappings.
The only workaround I can think of is to "manually" create such tags, e.g. using custom resources. Or as you are already using lambda, do it in your lambda after EMR cluster creation.
How do you include an optional list of AWS specific resources in a CloudFormation template?
For example, an optional list of existing EBS volumes to attach to an EC2 instance?
The parameter would be defined as usual:
AdditionalExistingVolumes:
Type: List<AWS::EC2::Volume::Id>
Description: Existing AWS volumes to attach to the instance.
However when it comes to use it, you only want to include the list if the user provided some values.
With a string parameter you would use a Condition along with the function !If to optional include AWS::NoValue.
How do you do this with a list of AWS types?
I have a Cloud Formation to set up an EC2 instance. I'm currently using the Parameters to specify the Subnet Id for the EC2 instance as well as the VPC Id for the Security Group (to be used in turn by the EC2 instance).
In my situation the Subnet Id specified is required to be part of the VPC and I'd like to only have to specify the Subnet Id in the Parameters. But I can't find a way to derive the VPC from the Subnet Id (http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-subnet.html)
I see the GetAtt function can be used to return resource attributes. Is there something equivalent to return resource properties?
From the documentation Fn:GetAtt, you can only retrieve AvailabilityZone and Ipv6CidrBlocks details of the Subnet. There is no inbuilt support to get VpcId of the given subnet in CFn Templates.
There is a work-around though. If you are using the aws-cli documentation, you can use the describe-subnets method to fetch the VpcId of the required subnet and pass it as input to the Cloudformation template create_stack call.
This method works even if you are using any SDK. for example, in Java.
//pseudo code only!
DescribeSubnetsRequest request = new DescribeSubnetsRequest();
request.withSubnetIds("subnet-abcdefgh");
DescribeSubnetsResult result = awsClient.describeSubnets(request);
String myVpc = result.getSubnets().get(0).getVpcId();
// add the above VPC Id to the parameters of your Cloud formation template create stack request.
Hope this helps.
I created a small project called cli2cloudformation. Using that you're able to execute cli commands inside your cloudformation stack and use the results of the commands.
Just check it here. I hope it helps you.