LeetCode-Bot

Get tired of manually committing your code to a Git repository everytime you have ACed a LeetCode problem?

LeetCode-Bot automatically monitors, fetches and commits your accepted LeetCode submissions to your specified Git repository.

Supports deploying as AWS Lambda function, or running on any machine with Node.js environment.

Table of Contents

• Table of Contents
• Prerequisites
• Deployment
  • AWS Serverless
  • Local Deployment
• Configuration
• Design Details
  • Why LeetCode Session
  • AWS Services
  • Is It Free?
  • Why One Iteration At A Time
• License

Prerequisites

• Node.js >= 12.x.
• To deploy on AWS:
  • An AWS Account (of course)
  • Python >= 3.6

Deployment

For whichever mode, AWS or Local, you need to compile the source TypeScript code first:

• Install dependencies by yarn install or npm install
• Compile by npm run build

AWS Serverless

LeetCode-Bot uses boto3 for access to AWS service APIs. Make sure proper AWS Authentication Credentials (Access Key Id & Secret Access Key) and region to deploy is specified in ~/.aws/credentials, see This Tutorial. The provided AWS authentication credentials should at least have the permission to create S3 Bucket, Lambda Function, CloudWatch Events and IAM Policy & Roles.

We provide scripts for deploying, updating and deleting LeetCode-Bot in the AWS under ./deploy, whose correspoding dependencies are listed in ./deploy/requirements.txt or ./deploy/Pipfile.

• cd deploy
• Install dependencies by pip3 install -r requirements.txt or pipenv install
• Edit config.yaml for your desired settings and credentials necessary for both AWS and Git, details listed in Configuration.
• Run deploy.py to deploy, cleanup.py to delete all deployed services, patch.py to rebuild and update LeetCode-Bot (if any), and update_session.py to upload new LeetCode session information (Why?).

Local Deployment

Local deployment is much simpler but it requires a host machine. After running npm run build, use LEETCODE_SESSION=<Cookie_Value> npm start -- --config=<path_to_config> to start LeetCode-Bot. An example of the configuration file is ./local-config-example.json, details explained in Configuration.

Note:

• LEETCODE_SESSION is an environment variable required by LeetCode-Bot (Details Here). It can be provided in command-line, or by creating a .env file at the root of this project with the content LEETCODE_SESSION=....
• LeetCode-Bot only runs One Iteration for each npm start ..., which fetches and processes only the oldest unfetched few (~100) submissions. This is in order to limit the frequency of LeetCode API calls. You can use tools like cron to create a scheduled LeetCode-Bot.

Configuration

• git.username & git.email: username and emails recorded in the git commits.
• git.relCodeDir: the relative path to the directory where code files will be committed in the repository.

Design Details

Why LeetCode Session

Since LeetCode uses Recaptcha to prevent from bots, we need to use the LEETCODE_SESSION cookie that is set when you sign in from the browser, to avoid the signin process.

AWS Services

In general, we use AWS Lambda triggered periodically by CloudWatch events, and S3 buckets to store Bot history.

Is It Free?

Well, these services have free tiers and in normal cases it should be fine.

Why One Iteration At A Time

This is to avoid long running time as AWS Lambda charges based on the running time and memory usage.

License

Distributed under the MIT License. See LICENSE for more information.

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TODOs:

• Telegram Notification
• DynamoDB instead of S3