streamer-quickstart

Streamer Quickstart - Lift v1.0.12

This is a complete working example of WebSocket support in Lift v1.0.12.

Quick Test

1. Verify your Lift version:

go list -m github.com/pay-theory/lift
# Should show: github.com/pay-theory/lift v1.0.12

1. If not v1.0.12, update it:

go get github.com/pay-theory/lift@v1.0.12
go mod tidy

1. Build the example:

go build -o streamer main.go

1. Deploy to AWS Lambda (example with SAM):

Create template.yaml:

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31

Resources:
  WebSocketApi:
    Type: AWS::ApiGatewayV2::Api
    Properties:
      Name: StreamerWebSocket
      ProtocolType: WEBSOCKET
      RouteSelectionExpression: "$request.body.action"

  ConnectRoute:
    Type: AWS::ApiGatewayV2::Route
    Properties:
      ApiId: !Ref WebSocketApi
      RouteKey: $connect
      Target: !Sub integrations/${ConnectIntegration}

  ConnectIntegration:
    Type: AWS::ApiGatewayV2::Integration
    Properties:
      ApiId: !Ref WebSocketApi
      IntegrationType: AWS_PROXY
      IntegrationUri: !Sub arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${StreamerFunction.Arn}/invocations

  StreamerFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: .
      Handler: streamer
      Runtime: go1.x
      Policies:
        - Statement:
          - Effect: Allow
            Action:
              - execute-api:ManageConnections
            Resource: !Sub arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${WebSocketApi}/*

Testing Locally

You can test the handler logic locally:

package main

import (
    "testing"
    "github.com/pay-theory/lift/pkg/lift"
)

func TestWebSocketHandler(t *testing.T) {
    app := lift.New(lift.WithWebSocketSupport())
    
    // Your handler registration here
    app.WebSocket("$connect", func(ctx *lift.Context) error {
        return ctx.Status(200).JSON(map[string]string{
            "status": "connected",
        })
    })
    
    // Test it
    // ... test code
}

Common Issues

"undefined: lift.WithWebSocketSupport"

• You're not using v1.0.12. Run: go get github.com/pay-theory/lift@v1.0.12

"app.WebSocket undefined"

• Clear module cache: go clean -modcache
• Re-download: go mod download

Build errors

• Make sure you have all dependencies:

  go get github.com/aws/aws-lambda-go/lambda
  go get github.com/aws/aws-lambda-go/events
  

What This Example Shows

1. Connection Management - Handling $connect and $disconnect
2. Authentication - Using query parameters for auth tokens
3. Message Routing - Routing messages based on action field
4. Broadcasting - Using WebSocket context to send messages
5. Error Handling - Proper error responses

Next Steps

1. Add DynamoDB connection store for real connection management
2. Implement room/channel functionality
3. Add metrics and monitoring
4. Set up CloudWatch logging

Need Help?

Run the verification script:

go run ../../scripts/verify-websocket-v1.0.12.go

This will check your environment and confirm WebSocket support is working.