exercises

go-exercises-backend

Back-end of the service for solving programming exercises.

Features

• RESTful API:
  • models:
    • task model:
      • storing:
        • author ID;
        • title;
        • description;
        • boilerplate code;
        • test cases:
          • all test cases are represented by a single string;
      • operations:
        • getting all tasks:
          • calculate a total correctness flag based on all solutions of a requesting author;
          • sort the results by creation time in descending order;
          • process pagination:
            • implemented using an offset and a limit;
        • getting a single task by an ID:
          • calculate a total correctness flag based on all solutions of a requesting author;
        • creating:
          • automatically format a task boilerplate code;
        • updating by an ID:
          • allowed for its author only;
          • automatically format a task boilerplate code;
        • deleting by an ID:
          • allowed for its author only;
    • solution model:
      • storing:
        • author ID;
        • task ID;
        • code;
        • correctness flag;
        • testing result:
          • represented by a string;
      • operations:
        • getting all solutions by a task ID:
          • filtered by a requesting author:
            • allow a solution task author to get solutions of other authors;
          • sort the results by creation time in descending order;
          • process pagination:
            • implemented using an offset and a limit;
        • getting a single solution by an ID:
          • allowed for:
            • solution author;
            • solution task author;
        • creating:
          • automatically format a solution code;
        • updating by an ID:
          • performed by a queue consumer only (see below);
        • formatting a solution code;
  • representing:
    • in a JSON:
      • payloads:
        • of requests;
        • of responses;
    • as a plain text:
      • errors;
• server:
  • additional routing:
    • serving static files;
  • storing settings in environment variables;
  • supporting graceful shutdown;
  • logging:
    • logging requests;
    • logging errors;
  • panics:
    • recovering on panics;
    • logging of panics;
• authentication:
  • use the Bearer authentication scheme based on JSON Web Tokens:
    • store in a JWT claims:
      • expiration time claim;
      • user claim:
        • contains a whole user model;
  • generate a token signing key automatically by default;
  • user model:
    • storing:
      • username (unique);
      • password hash:
        • generated using the bcrypt function;
      • flag indicating whether the user is disabled or not;
• databases:
  • storing data in the PostgreSQL database;
• interaction with queues:
  • using the RabbitMQ message broker;
  • common properties:
    • automatic declaring of the used queues;
    • passing of a message data in JSON;
  • operations:
    • producing solutions:
      • concurrent producing;
    • consuming solution results:
      • concurrent consuming;
      • once requeue the solution on failure;
• utilities:
  • utility for managing users:
    • commands:
      • add a user:
        • parameters:
          • username;
          • password;
          • password hashing cost;
          • flag indicating the need to generate a password;
          • generated password length;
          • flag indicating whether the user is disabled or not;
      • update a user:
        • parameters:
          • username;
          • new username;
          • password;
          • password hashing cost;
          • flag indicating the need to generate a password;
          • generated password length;
          • flag indicating whether the user is disabled or not;
          • flag indicating whether the user is enabled or not;
        • can update the user fields individually;
• distributing:
  • Docker image;
  • Docker Compose configuration.

Installation

Prepare the directory:

$ mkdir --parents "$(go env GOPATH)/src/github.com/thewizardplusplus/"
$ cd "$(go env GOPATH)/src/github.com/thewizardplusplus/"

Clone this repository:

$ git clone https://github.com/thewizardplusplus/go-exercises-backend.git
$ cd go-exercises-backend

Install dependencies with the dep tool:

$ dep ensure -vendor-only

Build the project:

$ go install ./...

Migration

The necessary tables will be created automatically on service starting.

Then run the manual migration to create a few example tasks (optionally):

$ ./tools/migrate.sh -h | --help
$ ./tools/migrate.sh

Options:

• -h, --help — show the help message and exit.

Environment variables:

• PATH_TO_MIGRATIONS — path to migrations (default: ./migrations);
• STORAGE_ADDRESS — PostgreSQL connection URI (default: postgres://postgres:postgres@localhost:5432/postgres?sslmode=disable).

The solutions for the example tasks: docs/solutions.

Usage

$ go-exercises-backend

Environment variables:

• SERVER_STATIC_FILE_PATH — path to static files (default: ./static);
• addresses:
  • SERVER_ADDRESS — server URI (default: :8080);
  • STORAGE_ADDRESS — PostgreSQL connection URI (default: postgres://postgres:postgres@localhost:5432/postgres?sslmode=disable);
  • MESSAGE_BROKER_ADDRESS — RabbitMQ connection URI (default: amqp://rabbitmq:rabbitmq@localhost:5672);
• solution registration:
  • SOLUTION_REGISTER_BUFFER_SIZE — solution registration channel capacity (default: 1000);
  • SOLUTION_REGISTER_CONCURRENCY — amount of solution registration threads (default: 1000);
• authorization:
  • AUTHORIZATION_TOKEN_SIGNING_KEY — authorization token signing key (is generated automatically if empty; default: empty);
  • AUTHORIZATION_TOKEN_TTL — authorization token TTL (default: 24h).

API Description

API description:

• RabbitMQ API description in the AsyncAPI format: docs/async_api.yaml;
• web API description:
  • in the Swagger format: docs/swagger.yaml;
  • in the format of a Postman collection: docs/postman_collection.json.

Utilities

• go-exercises-manager — utility for managing users

License

The MIT License (MIT)

Copyright © 2021-2022 thewizardplusplus