TODO Manager [Golang]

Introduction

• Use golang and gRPC to implement a microservices capable of storing TODO list data in mongodb.
• User should be able to create, query, update, and delete todo list items. Bonus: use bazel to build/deploy your go binary + container

Bonus: use bazel to build/deploy go binary + container

Functionality

• Runs a grpc server that allows users to:
  • create a todo item for a user, by default the status for todo is assumed to be NOT DONE/PENDING
  • query a todo based on ID
  • Update any values in the todo with a given ID
  • Delete todo list item
  • Query ALL the todos or todos based on a filter
    • Filters are:
      • Todo status - can be DONE/PENDING/ALL
      • USER ID - only returns todos for that user
• Stores all todods in local mondodb instance
  • username/passowrd as configured in the config file - dev.env
• The implementation creates a service layer interface, so that new functionalities can be easily added
• Also contains bazel docker rules to build and create a docker image with mongodb container running alongside it
• Please find attached screenshots for manual test runs

List of available RPCs (from Evans explained below)

+-------------+--------+-------------------+--------------------+
|   SERVICE   |  RPC   |   REQUEST TYPE    |   RESPONSE TYPE    |
+-------------+--------+-------------------+--------------------+
| ToDoService | Create | CreateItemRequest | TodoResponse       |
| ToDoService | Get    | GetItemByID       | TodoResponse       |
| ToDoService | Update | UpdateItemRequest | TodoResponse       |
| ToDoService | Delete | DeleteItemRequest | DeleteItemResponse |
| ToDoService | GetAll | GetItemsRequest   | ToDo               |
+-------------+--------+-------------------+--------------------+

Setup instructions

• Install

  • Go
  • Docker
  • Bazel
  • Mongodb
    • User/password config as present in dev.env
  • Evans
    • https://github.com/ktr0731/evans

• In project root, run

  • go mod tidy

• To clean previous state for subsequent runs

  • bazel clean --expunge

• Generate build files

  • bazel run //:gazelle

• Update repos/deps

  • bazel run :gazelle -- update-repos -from_file=go.mod -build_file_proto_mode=disable_global -to_macro=repositories.bzl%go_repositories

• Run the server

  • bazel run //cmd

• Open another terminal and run

  • evans --host localhost --port 8080 -r repl

• show available rpcs

  • show service

• Now call different rpcs

  • call Create
  • call Get
  • call Update
  • call Delete
  • call GetAll

• To run the tests:

  • bazel test --test_output=errors //... --@io_bazel_rules_docker//transitions:enable=no

• Get mongodb latest image and run a mongodb container

  • docker run -d -p 27017:27017 --name bazel-mongo -v mongo-data:/data/db mongo:latest

• Build docker image for our project and run it

  • bazel run --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64 //cmd:image --@io_bazel_rules_docker//transitions:enable=no -- -p 8080:8080 --name bazel-docker-app

Assumptions and future additions:

• Since we do not have user auth/sessions, we are expecting user_id in create todo requests, ideally it can be taken from current logged in user.
• No validation for user_id sent in create/update Todos for same reason as above.
• Task completion is just stored as a boolean value but could be kept as an enum for better handling (since proto removes default value of false for a boolean)
• Can have sorting/etc based on created_at/update_at
• Can have support for scheduling todos also