# Basic Lambda Function with AWS CLI

## Basic Lambda Function with AWS CLI

```bash
# Create Lambda execution role
aws iam create-role \
  --role-name lambda-execution-role \
  --assume-role-policy-document '{
    "Version": "2012-10-17",
    "Statement": [{
      "Effect": "Allow",
      "Principal": {"Service": "lambda.amazonaws.com"},
      "Action": "sts:AssumeRole"
    }]
  }'

# Attach basic execution policy
aws iam attach-role-policy \
  --role-name lambda-execution-role \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

# Create function from ZIP
zip function.zip index.js
aws lambda create-function \
  --function-name my-function \
  --runtime nodejs18.x \
  --role arn:aws:iam::ACCOUNT:role/lambda-execution-role \
  --handler index.handler \
  --zip-file fileb://function.zip \
  --timeout 30 \
  --memory-size 256 \
  --environment Variables={ENV=production,DB_HOST=db.example.com}

# Invoke function
aws lambda invoke \
  --function-name my-function \
  --payload '{"name":"John","age":30}' \
  response.json
```