srill

Subscribe Redis and Invoke Lambda with cargo lambda, for Local development.

Features

• Subscribe to multiple Redis channels simultaneously
• Invoke different Lambda functions for each channel
• Support for configuration files (TOML format)

Usage

First, run cargo lambda watch:

cargo lambda watch

If you change the watch port, configure the same port in srill:

cargo lambda watch --invoke-port 9011
srill --invoke-port 9011 --channels channel1=lambda-function1

Multiple Channels

Start srill with multiple channel-lambda pairs:

srill --channels channel1=lambda-function1,channel2=lambda-function2,channel3=lambda-function3

Configuration File

Create a srill.toml configuration file:

redis_url = "redis://localhost:6379"
invoke_port = 9000

[channels]
channel1 = "lambda-function1"
channel2 = "lambda-function2"
channel3 = "lambda-function3"

Then start srill:

srill --config srill.toml

Single Channel Mode

Start srill:

srill <channel name> <lambda binary name>

Publishing Messages

Publishing SQS Events

Publishers should create and publish SQS event JSON:

use redis::Commands;
use srill::events::sqs::{SqsEvent, SqsMessage};
use serde_json;

fn publish_message(conn: &mut redis::Connection) -> Result<(), Box<dyn std::error::Error>> {
    // Customize this event as you like.
    let event = SqsEvent {
        records: vec![SqsMessage {
            body: Some("Test message.".to_string()),
            ..Default::default()
        }],
    };

    let _: () = conn.publish("<channel_name>", &serde_json::to_string(&event)?)?;
    Ok(())
}

Message Format

The Lambda function receives the complete SQS event as published to Redis:

{
  "Records": [
    {
      "messageId": "<uuid-v4>",
      "receiptHandle": "<random string>",
      "body": "Test message.",
      "md5OfBody": "e62f489304eae26e9960977058872c3f",
      "attributes": {
        "ApproximateReceiveCount": "2",
        "SentTimestamp": "1520621625029",
        "SenderId": "sender",
        "ApproximateFirstReceiveTimestamp": "1520621634884"
      },
      "eventSourceARN": "arn:aws:sqs:ap-northeast-1:123456789012:SQSQueue",
      "eventSource": "aws:sqs",
      "awsRegion": "ap-northeast-1",
      "messageAttributes": {
        "Attribute3": {
          "binaryValue": "MTEwMA==",
          "stringListValues": ["abc", "123"],
          "binaryListValues": ["MA==", "MQ==", "MA=="],
          "dataType": "Binary"
        },
        "Attribute2": {
          "stringValue": "123",
          "stringListValues": [],
          "binaryListValues": ["MQ==", "MA=="],
          "dataType": "Number"
        },
        "Attribute1": {
          "stringValue": "AttributeValue1",
          "stringListValues": [],
          "binaryListValues": [],
          "dataType": "String"
        }
      }
    }
  ]
}

Options

• --redis-url: Redis URL (default: redis://localhost:6379)
• --invoke-port: Port passed to cargo lambda invoke (default: 9000)
• --channels: Channel-Lambda pairs in format channel1=lambda1,channel2=lambda2
• --config: Path to TOML configuration file

When both --invoke-port and srill.toml specify a port, the CLI option wins.

Examples

# Multiple channels via command line
srill --redis-url redis://localhost:6379 --channels user-events=user-lambda,order-events=order-lambda

# Matching a non-default cargo lambda watch port
srill --invoke-port 9011 --channels user-events=user-lambda

# Using configuration file
srill --config ./config/srill.toml

# Single channel
srill my-channel my-lambda

License

MIT