CloudFormation pass tags - amazon-web-services

I want to have an option to pass to my CFT tags so I could tag S3 bucket that I am creating and that it will not be mandatory - to have default value. How ever I cannot find any parameter type that will do the trick

In order to set a default value to cloudformation parameters, you need to use the Default attribute when you define the parameter.
The following template snippet creates S3 Bucket and add the relevant tag(single one!) based on user input :
AWSTemplateFormatVersion: 2010-09-09
Description: Create S3 Bucket with relevant tags
Parameters:
S3TagKey:
Description: The S3 Tag key
Type: String
Default: Your Default key
S3TagValue:
Description: The S3 Tag Value
Type: String
Default: Your Default Value
Resources:
ExampleS3:
Type: 'AWS::S3::Bucket'
Properties:
BucketName: s3-name
Tags:
- Key: !Ref S3TagKey
Value: !Ref S3TagValue
PublicAccessBlockConfiguration:
BlockPublicAcls: true
BlockPublicPolicy: true
IgnorePublicAcls: true
RestrictPublicBuckets: true
When you click on create stack you will be asked to provide the key-value pair values, As you can see the default values are set already. In case you want to change the tags, just update the relevant field.
Results :

Related

How to input the dictionary structure in 'values' argument using the aws_ssm_parameter in cloudformation

I have one parameter in AWS System Manager, type of the value is string, but value has a dictionary structure:
Value:
{"key1": "value1","key2": "value2","key3": "value3"}
Now i'm trying to create this parameter using the cloudformation. But i received an error, when trying to write this in cloudformation:
AWSTemplateFormatVersion: "2010-09-09"
Description: Systems Manager Parameter Store Parameters
Resources:
Test-Channels:
Type: AWS::SSM::Parameter
DeletionPolicy: Delete
Properties:
Name: test-Channels
Description:Lambda required parameter key and values
Type: String
Value: "{ "key1": "value1","key2": "value2", "key3", "value3"}"
error from cloudformation:
Property validation failure: [Value of property {/Value} does not match type {String}]
could someone please advise what I did wrong or the proper way of assigning dictionary type of value to parameter name using cloudformation?
Thank a lot!
You can use single quotes:
AWSTemplateFormatVersion: "2010-09-09"
Description: Systems Manager Parameter Store Parameters
Resources:
TestChannels:
Type: AWS::SSM::Parameter
DeletionPolicy: Delete
Properties:
Name: test-Channels
Description: Lambda required parameter key and values
Type: String
Value: dddd
Value: '{ "key1": "value1","key2": "value2", "key3", "value3"}'

Update AWS Athena workgroup using CloudFormation template

I have 2 templates those I have taken from the AWS::Athena::WorkGroup - AWS CloudFormation documentation.
The first template athena_create.yaml works as expected. The second template needs to modify the workgroup created in the first template. But I get an error:
MyCustomWorkGroup already exists in stack
arn:aws:cloudformation:us-east-1:XXX:stack/a1/7cc670a0-8d19-11ea-872c-12217e59f19f
Here is the code. create template works correctly.
athena_create.yaml
Resources:
MyAthenaWorkGroup:
Type: AWS::Athena::WorkGroup
Properties:
Name: MyCustomWorkGroup
Description: My WorkGroup
State: ENABLED
Tags:
- Key: "key1"
Value: "value1"
- Key: "key2"
Value: "value2"
WorkGroupConfiguration:
BytesScannedCutoffPerQuery: 200000000
EnforceWorkGroupConfiguration: false
PublishCloudWatchMetricsEnabled: false
RequesterPaysEnabled: true
ResultConfiguration:
OutputLocation: s3://path/to/my/bucket/
athena_update.yaml
Resources:
MyAthenaWorkGroup:
Type: AWS::Athena::WorkGroup
Properties:
Name: MyCustomWorkGroup
Description: My WorkGroup Updated
State: DISABLED
Tags:
- Key: "key1"
Value: "value1"
- Key: "key2"
Value: "value2"
WorkGroupConfigurationUpdates:
BytesScannedCutoffPerQuery: 10000000
EnforceWorkGroupConfiguration: true
PublishCloudWatchMetricsEnabled: true
RequesterPaysEnabled: false
ResultConfigurationUpdates:
EncryptionConfiguration:
EncryptionOption: SSE_S3
OutputLocation: s3://path/to/my/bucket/updated/
The update template mentioned above does not work as expected.
The reason for the error is that the two templates were used to create two independent stacks. This didn't work because they two Athena WorkGroups of same Name: MyCustomWorkGroup.
The correct way to perform create and update the MyCustomWorkGroup is as follows:
Create a stack using athena_create.yaml file.
Once the stack is created, use its Update option to upload athena_update.yaml which is going to update the stack.

How to get the ARN of an SSM Document in CloudFormation?

I have a CloudFormation template that creates an AWS::Events::Rule and an AWS::SSM::Document. I need to provide a list of Targets for the SSM::Rule, but each target expects an ARN:
mySSMDocument:
Type: AWS::SSM::Document
Properties:
DocumentType: 'Command'
Content:
schemaVersion: '2.2'
description: "Code that will be run on EC2"
mainSteps:
- action: "aws:runShellScript"
name: runShellScript
inputs:
runCommand:
- 'Some command to execute'
myEventRule:
Type: AWS::Events::Rule
Properties:
Description: "A description for the Rule."
EventPattern:
source:
- "aws.autoscaling"
detail-type:
- "EC2 Instance-terminate Lifecycle Action"
detail:
AutoScalingGroupName:
- !Ref 'someAutoScalingGroupInThisTemplate'
RoleArn: 'some role ARN'
State: "ENABLED"
Targets:
- Id: "some-unique-id"
Arn: <-- This is the value that I need to fill in.
RunCommandParameters:
RunCommandTargets:
- Key: "tag: Name"
Values:
- 'The name of the EC2 machine'
I think that I need to replace the <-- This is the value that I need to fill in. with the ARN of mySSMDocument, but I don't see any way to retrieve this value from within the template itself. The documentation does not specify any GetAtt functionality on SSM::Document that allows to get the ARN. Anyone know how to solve this issue?
This is ARN pattern of Document
arn:${Partition}:ssm:${Region}:${Account}:document/${DocumentName}
example:
arn:aws:ssm:us-east-2:12345678912:document/demoooo
You can use Ref function to get name of document, then Sub to create final ARN
refer: https://docs.aws.amazon.com/IAM/latest/UserGuide/list_awssystemsmanager.html#awssystemsmanager-resources-for-iam-policies
!Sub arn:${AWS::Partition}:ssm:${AWS::Region}:${AWS::AccountId}:document/${mySSMDocument}
You can produce the ARN format for AWS::SSM::Document using the return Value for AWS::SSM::Document, the Pseudo Parameters for Partition, Region, and AccountId, and the Sub intrinsic function

How to check if a parameter exists in Systems Manager from CloudFormation

Reading the AWS documentation here, I've found the following statement:
AWS::SSM::Parameter::Name
The name of a Systems Manager parameter key.
Use this parameter when you want to pass the parameter key. For example, you can use this type to validate that the parameter exists.
I wasn't able to make it work, every time I get: Parameter validation failed: parameter value ... for parameter name ... does not exist.
Shoud it be trying to resolve the parameter type AWS::SSM::Parameter::Name? Anyway, I kept searching and found another statement here:
The first one in the list is used to pass the name of the parameter key as-is. CloudFormation will not fetch the value stored against it. For example, you can use this type to validate that the parameter exists in Parameter Store.
I'm probably not understanding it correctly, so I would like to request an example on how to check if a parameter existis in Systems Manager from CloudFormation?
Use case:
My main region has all parameters stored on Systems Manager, but my second one (redundancy) has only a few. Consider as example not creating the Zone/RecorSet twice in each region. For that I use a condition, as shown bellow:
AWSTemplateFormatVersion: '2010-09-09'
Parameters:
MainRegion:
Type: String
Default: 'us-east-1'
PrivateFullyQualifiedDomainName:
Type: 'AWS::SSM::Parameter::Name'
Default: '/company/route53/private'
Conditions:
CreateUniqueResources: !Equals [ !Ref 'AWS::Region', !Ref MainRegion ]
Resources:
Route53Stack:
Type: 'AWS::CloudFormation::Stack'
Condition: CreateUniqueResources
Properties:
TemplateURL: [some s3 bucket]
Parameters:
PrivateDomainName: !Ref PrivateFullyQualifiedDomainName
Outputs:
TestParameterName:
# Outputs: /company/route53/private
Value: !Ref PrivateFullyQualifiedDomainName
And the nested stack:
AWSTemplateFormatVersion: '2010-09-09'
Parameters:
PrivateDomainName:
Type: 'AWS::SSM::Parameter::Value<String>'
Resources:
[sutff...]
Outputs:
TestParameterValue:
# Outputs WHEN it exists: supersecretdomain.company.com
Value: !Ref PrivateDomainName

Cloudformation & Parameter Store: How to select parameter for the environment

I want to read the URL of my database from parameter store in my CloudFormation template. This is easy enough for a single URL, but I can't figure out how to change the URL with different environments.
I have four environments (development, integration, pre-production and production) and their details are stored on four different paths in Parameter Store:
/database/dev/url
/database/int/url
/database/ppe/url
/database/prod/url
I now want to pick the correct Database URL when deploying via CloudFormation. How can I do this?
Parameters:
Environment:
Type: String
Default: dev
AllowedValues:
- dev
- int
- ppe
- prod
DatabaseUrl:
Type: 'AWS::SSM::Parameter::Value<String>'
# Obviously the '+' operator here won't work - so what do I do?
Default: '/database/' + Environment + '/url'
This feature isn't as neat as one would wish. You have to actually pass name/path of each parameter that you want to look up from the parameter store.
Template:
AWSTemplateFormatVersion: 2010-09-09
Description: Example
Parameters:
BucketNameSuffix:
Type: AWS::SSM::Parameter::Value<String>
Default: /example/dev/BucketNameSuffix
Resources:
Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: !Sub parameter-store-example-${BucketNameSuffix}
If you don't pass any parameters to the template, BucketNameSuffix will be populated with the value stored at /example/dev/BucketNameSuffix. If you want to use, say, a prod value (pointed to by /example/prod/BucketNameSuffix), then you should specify value for parameter BucketNameSuffix, but instead of passing the actual value you should pass the alternative name of the parameter to use, so you'd pass /example/prod/BucketNameSuffix.
aws cloudformation update-stack --stack-name example-dev \
--template-body file://./example-stack.yml
aws cloudformation update-stack --stack-name example-prod \
--template-body file://./example-stack.yml \
--parameters ParameterKey=BucketNameSuffix,ParameterValue=/example/prod/BucketNameSuffix
A not so great AWS blog post on this: https://aws.amazon.com/blogs/mt/integrating-aws-cloudformation-with-aws-systems-manager-parameter-store/
Because passing million meaningless parameters seems stupid, I might actually generate an environment-specific template and set the right Default: in the generated template so for prod environment Default would be /example/prod/BucketNameSuffix and then I can update the prod stack without passing any parameters.
You can populate CloudFormation templates with parameters stored in AWS Systems Manager Parameter Store using Dynamic References
In this contrived example we make two lookups using resolve:ssm and replace the environment using !Join and !Sub
AWSTemplateFormatVersion: 2010-09-09
Parameters:
Environment:
Type: String
Default: prod
AllowedValues:
- prod
- staging
Resources:
TaskDefinition:
Type: AWS::ECS::TaskDefinition
Properties:
ContainerDefinitions:
Image: !Join
- ''
- - 'docker.io/bitnami/redis#'
- !Sub '{{resolve:ssm:/app/${Environment}/digest-sha/redis}}'
Environment:
- Name: DB_HOST
Value: !Sub '{{resolve:ssm:/app/${Environment}/db-host}}'
You can make use of Fn::Join here.
Here is some pseudo code.
You will have to take Environment as an parameter, which you are already doing.
Creating the required string in the resources where DatabaseUrl is required.
Resources :
Instance :
Type : 'AWS::Some::Resource'
Properties :
DatabaseURL : !Join [ "", [ "/database/", !Ref "Environment" , "/url ] ]
Hope this helps.
Note: You cannot assign value to a Parameter dynamically using some computation logic. All the values for defined parameters should be given as Input.
I like Fn::Sub, which is much cleaner and easy to read.
!Sub "/database/${Environment}/url"
I am stuck into the same problem, below are my findings:
We can compose values and descriptions while writing into the SSM Parameter Store from CloudFormation like below :
LambdaARN:
Type: AWS::SSM::Parameter
Properties:
Type: String
Description: !Sub "Lambda ARN from ${AWS::StackName}"
Name: !Sub "/secure/${InstallationId}/${AWS::StackName}/lambda-function-arn"
Value: !GetAtt LambdaFunction.Arn
We can not compose values/defaults to looking for in SSM Parameter Store. Like below:
Parameters:
...
LambdaARN:
Type: Type: AWS::SSM::Parameter::Value<String>
Value: !Sub "/secure/${InstallationId}/teststack/lambda-function-arn"
This is not allowed as per AWS Documentation[1]. Both(Sub/Join) Functions won't work. Following is the error which I was getting:
An error occurred (ValidationError) when calling the CreateChangeSet
operation: Template format error: Every Default member must be a
string.
Composing and passing values while creating stacks can be done like this:
Parameters:
...
LambdaARN:
Type: Type: AWS::SSM::Parameter::Value<String>
....
$ aws cloudformation deploy --template-file cfn.yml --stack-name mystack --parameter-overrides 'LambdaARN=/secure/devtest/teststack/lambda_function-arn'
If you add your custom tags while putting the values in the Parameter Store, it will overwrite the default tags added by CFN.
Default Tags:
- aws:cloudformation:stack-id
- aws:cloudformation:stack-name
- aws:cloudformation:logical-id
Every time we update the values in parameter store, it creates a new version, which is beneficial when we are using DynamicResolvers, this can serve as a solution to the problem in the question like
{{ resolve:ssm:/my/value:1}}
The last field is the version. Where different versions can point to different environments.
We are using versions with the parameters, and adding the labels to them[2], this can't be done via CFN[3], only possible way via CLI or AWS Console. This is AWS's way of handling multiple environments.
[1] https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference.html
[2] https://docs.aws.amazon.com/systems-manager/latest/userguide/sysman-paramstore-labels.html
[3] https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ssm-parameter.html