Cloud Cost Saver

A Rust-based tool for analyzing infrastructure-as-code templates, such as CloudFormation, and providing actionable suggestions to optimize cloud costs.

Note: This project is ongoing and actively developed.

Features

• Analyze CloudFormation templates
• Identify cost-saving opportunities
• Provide actionable suggestions
• Currently supports AWS CloudFormation

Installation

To install Cloud Cost Saver, clone the repository from GitHub:

git clone https://github.com/yourusername/cloud-cost-saver.git
cd cloud-cost-saver

Usage

To analyze a CloudFormation template, use the following command:

cargo run -- aws --template src/fixtures/aws/cfn-testing.yaml --environment default --samconfig src/fixtures/aws/samconfig.toml --config .cloudsaving.yaml

Example Output

When you run the analysis, you might see output similar to the following:

LAMBDA-002: MyLambdaFunction2: Consider using ARM architecture. Lambda functions on ARM can be up to 20% cheaper than equivalent x86 functions.
src/fixtures/aws/cfn-testing.yaml:20

In this output:

• LAMBDA-002 is the error code.
• MyLambdaFunction2 is the resource name.
• The text following the resource name is the issue description.
• src/fixtures/aws/cfn-testing.yaml:20 is the file path and line number where the issue was found.

Violations

AWS CloudFormation

This section lists the various violations that this tool can detect in AWS CloudFormation templates. Each violation is identified by an error code and includes a description of the issue and whether it is enabled by default.

Lambda

Error Code	Description	Default enabled
LAMBDA-001	Lambda function creates a log group automatically when invoked for the first time with no expiry Please explicitly create a log group with a retention policy.	true
LAMBDA-002	Consider using ARM architecture. Lambda functions on ARM can be up to 20% cheaper than equivalent x86 functions.	false
LAMBDA-003	The Lambda function is missing a tag. Tags are useful for budgeting and identifying areas for cost optimization.	false
LAMBDA-004	Asynchronously invoked Lambda functions have a default maximum retry attempts set to 2. Consider setting the maximum retry attempts to 0 to prevent unnecessary retries. For example, if your Lambda function is invoked via an SQS queue with 3 retries, a failure event may result in up to 9 retries.	true
LAMBDA-005	Set the POWERTOOLS_LOG_LEVEL environment variable to appropriate logging levels for different environments when using AWS Lambda Powertools. This helps in reducing logging costs.	false
LAMBDA-006	Logging every incoming event may significantly increase cloud costs. Consider disabling POWERTOOLS_LOGGER_LOG_EVENT in the production environment to help reduce logging expenses.	true
LAMBDA-007	Set the POWERTOOLS_LOGGER_SAMPLE_RATE environment variable to a value between 0 and 1 to sample logs and reduce logging costs when using AWS Lambda Powertools.	false

CloudWatch

Error Code	Description	Default enabled
CW-001	The log group retention period is too long. Consider reducing it to save costs and improve log management efficiency.	false
CW-002	The log group has no retention policy. Consider setting a retention policy to save costs and improve log management efficiency.	true
CW-003	The log group is using STANDARD class. Consider using INFREQUENT_ACCESS to save costs.	false

Configuration

AWS CloudFormation

To configure the Cloud Cost Saver for AWS CloudFormation, create a .cloudsaving.yaml file in the root of your project. This file should contain the following settings:

cloudformation:
    rules:
        LAMBDA_001:
            enabled: true
        LAMBDA_002:
            enabled: true
        LAMBDA_003:
            enabled: true
            values:
                - tag1
                - tag2
        LAMBDA_004:
            enabled: true
            threshold: 0
        LAMBDA_005:
            enabled: true
            value: "ERROR"
        CW_001:
            enabled: true
            threshold: 14
        CW_002:
            enabled: true
        CW_003:
            enabled: false

In this configuration:

• LAMBDA_001, LAMBDA_002, and LAMBDA_003 are enabled, with LAMBDA_003 requiring specific tags (tag1 and tag2) and LAMBDA_004 with a threshold of 0 for retry attempts.
• CW_001 is enabled with a threshold of 14 days for log retention.
• CW_002 is enabled to ensure log groups have a retention policy.
• CW_003 is disabled, meaning it will not check for the use of the INFREQUENT_ACCESS class for log groups.

Rules configuration table

The .cloudsaving.yaml file allows you to customize the behavior of the Cloud Cost Saver tool. The below table lists all the rules configurations, specifying whether they are simple (only need to specify enabled or not), value, values, or threshold.

Rule Type	Configuration Type	Description
LAMBDA_001	Simple	Enabled or not
LAMBDA_002	Simple	Enabled or not
LAMBDA_003	Values	List of required tags
LAMBDA_004	Threshold	Lambda maximum retry attempts
LAMBDA_005	Value	POWERTOOLS_LOG_LEVEL value
LAMBDA_006	Simple	Enable to check if POWERTOOLS_LOGGER_LOG_EVENT is set to false
LAMBDA_007	Threshold	Set sample rate with POWERTOOLS_LOGGER_SAMPLE_RATE
CW_001	Threshold	Log retention period in days
CW_002	Simple	Enabled or not
CW_003	Simple	Enabled or not

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub.

License

This project is licensed under the MIT License. See the LICENSE file for details.