rust-lambda-deploy

AWS Lambda Rust — Deploy

Deploy the compiled Rust binary to AWS Lambda.

Context from $ARGUMENTS

• Deployment method: cargo-lambda (simplest), aws-cli, or sam
• Function name (if known)
• Existing IAM role ARN (if available)
• AWS account/region configuration status

Prerequisites: Configure AWS credentials

Before deploying, ensure AWS credentials are configured:

aws configure

Method 1: Deploy with Cargo Lambda (recommended for development)

Cargo Lambda's deploy subcommand automatically creates an execution role and the Lambda function:

cargo lambda deploy <function-name>

To use an existing IAM execution role:

cargo lambda deploy <function-name> --iam-role arn:aws:iam::111122223333:role/lambda-role

Method 2: Deploy with the AWS CLI

Step 1: Build the .zip package

cargo lambda build --release --output-format zip

Step 2: Create the Lambda function

Critical parameters:

• --runtime provided.al2023 — the OS-only runtime required for Rust compiled binaries and custom runtimes
• --handler rust.handler — the handler identifier for Rust functions
• --zip-file fileb://target/lambda/<function-name>/bootstrap.zip

aws lambda create-function \
  --function-name <function-name> \
  --runtime provided.al2023 \
  --role arn:aws:iam::111122223333:role/lambda-role \
  --handler rust.handler \
  --zip-file fileb://target/lambda/<function-name>/bootstrap.zip

Update an existing function's code:

aws lambda update-function-code \
  --function-name <function-name> \
  --zip-file fileb://target/lambda/<function-name>/bootstrap.zip

Method 3: Deploy with AWS SAM CLI

Step 1: Create a SAM template (template.yaml)

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: SAM template for Rust binaries
Resources:
  RustFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: target/lambda/<function-name>/
      Handler: rust.handler
      Runtime: provided.al2023
Outputs:
  RustFunction:
    Description: "Lambda Function ARN"
    Value: !GetAtt RustFunction.Arn

For ARM64/Graviton2, add under Properties:

Architectures:
  - arm64

Step 2: Build

cargo lambda build --release

Step 3: Deploy

sam deploy --guided

IAM execution role requirements

The Lambda execution role must include the permissions your function uses. Common policies:

• Basic execution: AWSLambdaBasicExecutionRole (CloudWatch Logs)
• S3 write: add s3:PutObject on the target bucket
• DynamoDB: add relevant DynamoDB actions

After deploying, remind the user to:

1. Set required environment variables in the Lambda console or via CLI
2. Verify the execution role has all required IAM permissions
3. Run /rust-lambda:invoke to test the deployed function