dlydiard / ddd-cqrs-es-aws-sam Goto Github PK

AWS SAM supports x-ray for lambda function, update template to support x-ray.

SAM Templates doesn't support this directly yet. So CloudFormation syntax would have to be used.

Hi,

Thanks for publishing this- your repo has been very helpful for understanding CQRS and event sourcing. I am wondering why you chose to create a service class call the repository from the service class, rather than directly from the command handler? I was trying to find more information about services in command handlers but did not find much. Thanks!

.env file isn't used in the same sense a standalone node application would use one.

AWS SAM cli supports JSON files as parameter inputs via --env-vars

one of the drivers for creating this project, is that i couldn't find any examples of DDD/CQRS/Event Sourcing using AWS serverless architecture.

most node frameworks like nestjs and node-ts/bus only work as a standalone node application.

auto-dll plugin makes builds significantly faster, but currently breaks CodeBuild. auto-dll-plugin also breaks debugging with the current (commented out) approach, since the dll file and lambda function are merged, but the source map files are not re-mapped.

A set validation interface/service should be created which uses the SetValidationRepository as its implementation. It should not be assumed a repository is used to implement Set Validation.

this depends on #7, or alternatively create mock objects for tests that include aws resources...

also, create a UT to stress test event ordering and this race condition scenario #2

see https://www.slideshare.net/koenighotze/eventsourcing-you-are-doing-it-wrong-bedcon-2018-edition (slide 90)

this will allow unit testing of code that touches aws resources, and running locally without first deploying to cloud formation.

Gets stuck at "92% chunk asset optimization TerserPlugin"
See webpack-contrib/uglifyjs-webpack-plugin#272

This is a webpack build issue

code should handle scenarios when services go down or fail. strict ordering needs to stay intact on retries, or services need to be idempotent.

create UT's and/or test harnesses for these scenarios.

https://github.com/aws/aws-cdk

look into using decorators in code to execute CDK, similar to https://docs.nestjs.com/recipes/swagger.

this will help a lot with step function generation through code.

Race condition can happen where projection doesn't exist when dealing with event enrichment, since aggregates are managed within their own queues.

This scenario should be rare since the API consumer would have to issue updates without first doing reads.

Add https://github.com/mauricedb/polly-js to use wait/retry logic.

New logic needs to account for new record creation (skip fetching record)

since AWS SAM doesn't support step functions directly, i left this out of the project.

creating step functions in templates is a bit messy and creates hard to maintain code. see #12 which will make step function creation much cleaner.

not happy with current structure... see #14 which can dictate the new structure.