DEV Community: Signet Seal

Enable Lambda Insights Using Python AWS CDK

chrishart0 — Tue, 23 Nov 2021 03:17:17 +0000

Code for enabling Lambda Insights with the Python CDK

# Define the layer, make sure you use the right layer for your region and the pick the most up to date layer https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Lambda-Insights-extension-versions.html

layerArn='arn:aws:lambda:us-east-1:580247275435:layer:LambdaInsightsExtension:14'
insight_layer = _lambda.LayerVersion.from_layer_version_arn(self,'lambda_insights_layer',layerArn)

#Add the layer to the function as shown below
_lambda.Function(
    self, 'my_function',
    runtime=_lambda.Runtime.PYTHON_3_8,
    handler='my_function.handler',
    code=_lambda.Code.from_asset(
        path = 'lambda'
    ),
    layers=[insight_layer]
)

# Optional: Add the managed policy 
If using the `AWSLambdaBasicExecutionRole`, which CDK uses by default when creating a Lambda function, there is no need to do this. Otherwise, add the `CloudWatchLambdaInsightsExecutionRolePolicy` managed policy to the function.

Note: make sure to pick the most up to date and correct region ARN for the Lambda Insights Extension layer. Reference these docs here for ARNs for all regions and version

Here are the AWS docs on how to enable Lambda Insights for the Typescript CDK.

Configure CORS for an S3 Bucket Using Python AWS CDK

chrishart0 — Tue, 23 Nov 2021 02:41:54 +0000

Get right to it, here is the code

Python CDK code for configuring CORS on an S3 bucket.

bucket = s3.Bucket(self, "myBucket",
    cors=[
        s3.CorsRule(
            allowed_headers=[CORS_headers],
            allowed_methods=[s3.HttpMethods.PUT, s3.HttpMethods.POST, s3.HttpMethods.GET, s3.HttpMethods.DELETE],
            allowed_origins=[CORS_url]
        )
    ]
)

A list of the HTTP methods which can be configured can be found here in the aws_cdk.aws_s3.HttpMethods docs

Relevant docs:

Create S3 Lifecycle Rules with Tag Filters Using Python AWS CDK

chrishart0 — Thu, 21 Oct 2021 23:55:21 +0000

Get right to it, here is the code

Python CDK code for creating an S3 bucket with a lifecycle rule which uses a tag filter.

bucket = s3.Bucket(self, "myBucket",
    lifecycle_rules = [
        s3.LifecycleRule(
            id="example-rule-made-with-python-cdk",
            expiration=core.Duration.days(1),
            tag_filters={ 
                'Key': 'delete_in_1_day', 
                'Value': 'true'
            }
        )
    ]
)

Relevant CDK docs:

Note: AWS Lifecycle rules do not get more precise than 24 hours[docs].

Create CloudWatch Alarms with Python AWS CDK

chrishart0 — Thu, 21 Oct 2021 23:24:14 +0000

Create the alarm

Put this into your Python AWS CDK stack to create an alarm on a bucket asigned to a varibale named bucket

bucket = s3.Bucket...

s3_size_alarm = cloudwatch.Alarm(self, 'bucket_overloaded_alarm',
    metric= cloudwatch.Metric(
        namespace = "AWS/S3", 
        metric_name = "BucketSizeBytes",
        dimensions={
            "BucketName": bucket.bucket_name,
            "StorageType": "StandardStorage",
        },
        period = core.Duration.days(1),
        statistic="Maximum",
    ), 
    evaluation_periods=1, 
    threshold=1000000000 #1 GB
)

This will create a CloudWatch alarm which:

Alarm if the size of the bucket goes over 1GB
Only monitors objects with the StandardStorage type

Relevant CDK docs:

Warning: Don't rely on an alarm watching the BucketSizeBytes metric to make sure your bucket doesn't grow too large. This metric is only collected once a day. Consider opting in to S3 request metrics for more in-depth S3 monitoring

Create alarm action

Alarms aren't very useful if they don't do anything. Setup some actions:

topic = sns.Topic.from_topic_arn(self,'snstopic',"arn:aws:sns:us-east-1:123456789012:alarm-go-ahhhhhhhhhhhh")

s3_size_alarm.add_alarm_action(
    cloudwatch_actions.SnsAction(
        topic = topic
    )
)

Relevant CDK docs:

https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_sns/Topic.html#aws_cdk.aws_sns.Topic.from_topic_arn

DEV Community: Signet Seal

Enable Lambda Insights Using Python AWS CDK

Code for enabling Lambda Insights with the Python CDK

More CDK or AWS Serverless Questions?

Configure CORS for an S3 Bucket Using Python AWS CDK

Get right to it, here is the code

More CDK or AWS Serverless Questions?

Create S3 Lifecycle Rules with Tag Filters Using Python AWS CDK

Get right to it, here is the code

More CDK or AWS Serverless Questions?

Create CloudWatch Alarms with Python AWS CDK

Create the alarm

Create alarm action

More CDK or AWS Serverless Questions?