⏲️ Beavuck Time

📊 Status

💡 Why

You can't count on client devices to all be set up with the correct date and time.

But keeping track of time is usually busywork, not the business of your core APIs. And you probably don't want to flood your own APIs, whenever you want to get an accurate timestamp for entities in your apps.

So you can set up this simple microservice, whose only job should be to answer the question: "what time is it right now?"

🎯 What

Get the current time in ISO format, in UTC timezone.

This lightweight service focuses on one job.

It needs no persistence layer, is capable of handling multiple concurrent requests, and is protected by a simple CORS config for security and performance reasons.

Dockerized for easy deployment and scaling.

🔍 Where

The code lives on GitLab, the Docker image is hosted on Docker Hub, and it's also stored as a package on NPM

🦊 GitLab

You can find the code on GitLab, where, once you have read the CONTRIBUTING.md file, you can also create issues and merge requests.

Feel free to fork the repo and make your own changes at will, as per the UNLICENSE.

🐳 Docker Hub

Most devs will only use Docker Hub for their purposes with this project, to use it as is as a dependency for their own projects. On Docker Hub, while you're developing, you should use the beavuck/time:latest tag to always get the latest version.

When the time comes to go to production, to protect yourself from surprise breaking changes, you should instead point to specific minor version tags, such as beavuck/time:2.0 : those will not get breaking changes, but they will get security updates and bug fixes while they're active.

Ⓝ NPM

You can also use this service directly via npm:

npm install beavuck-time

Programmatically

If you want to run this service programmatically in your Node.js project:

import { startServer } from 'beavuck-time'

startServer({
  hostUrl: 'https://time-api.example.com',
  trustedOrigins: 'https://my.app.com, https://my.app.com/*, https://my-other.app.com, https://my-other.app.com/*',
  apiPort: 3000
})

You can rely on environment variables (BEAVUCK_TIME_HOST_URL, etc.) together with (or instead of) passing an options object. Refer to the Docker Compose example below to see an exhaustive list of available environment variables and what they do.

CLI

To run this service directly in your command line interface, just run:

npx beavuck-time

Refer to the Docker Compose example below to see an exhaustive list of available environment variables and what they do.

⚙️ Usage

🪧 Set up (docker-compose example)

(The section below supposes you're using a Docker image. If using the npm package, you can set those environment variable on the host directly, instead of doing so in the container like detailed below)

To run the service in a docker-compose environment, add this in your docker-compose.yml's services section:

time:
    image: beavuck/time:latest
    ports:
        - 'SOME_PORT_NUMBER:3000'
        # HOST_PORT:CONTAINER_PORT (Since we are in a container, CONTAINER_PORT corresponds to the API_PORT variable below)
    environment:
        - BEAVUCK_TIME_HOST_URL: https://time-api.example.com
        # BEAVUCK_TIME_HOST_URL: That API's URL. Essential for CORS config.
        - BEAVUCK_TIME_TRUSTED_ORIGINS: https://my.app.com,https://my-other.app.com
        # BEAVUCK_TIME_TRUSTED_ORIGINS: To allow requests from any origin, include * (not recommended). If empty, will only allow requests from the HOST_URL's origin. Defaults to the HOST_URL's origin
        - BEAVUCK_TIME_API_PORT: 3000
        # BEAVUCK_TIME_API_PORT: Optional. Internal port when in a container. Defaults to 3000
        - BEAVUCK_TIME_RATE_LIMIT: -1
        # BEAVUCK_TIME_RATE_LIMIT: Optional. Max allowed number of requests per minute for each IP address. If negative or 0, no limit. Defaults to no limit
        - BEAVUCK_TIME_LOG_LEVEL: info
        # BEAVUCK_TIME_LOG_LEVEL: Optional. Logging levels include error, warn, info, http, verbose, debug, silly. Defaults to info
        - BEAVUCK_TIME_MAX_LOG_FILES: 64
        # BEAVUCK_TIME_MAX_LOG_FILES: Optional. Maximum number of logs to keep. This can be a number of files or number of days. If using days, add 'd' as the suffix. Default is 64
        - BEAVUCK_TIME_MAX_SIZE_LOG_FILES: 1m
        # BEAVUCK_TIME_MAX_SIZE_LOG_FILES: Optional. Maximum size of the file after which it will rotate. This can be a number of bytes, or units of kb, mb, and gb. If using the units, add 'k', 'm', or 'g' as the suffix. The units need to directly follow the number. Default is 1m

Here's the simple docker compose file I used to test this service locally:

services:
    time:
        image: beavuck/time:latest
        ports:
            - '3000:3000'
        environment:
            BEAVUCK_TIME_HOST_URL: http://127.0.0.1:3000
            BEAVUCK_TIME_TRUSTED_ORIGINS: http://127.0.0.1:8000,http://localhost:8000
            BEAVUCK_TIME_LOG_LEVEL: debug

When you're ready, just run your services with:

docker compose up -d

✨ Using the service

Now, when you run:

curl --location 'http://localhost:{{SOME_PORT_NUMBER}}/now' \
--header 'Origin: {{SOME_TRUSTED_ORIGIN}}'

you should expect an answer such as:

{
    "now": "2024-06-15T12:35:48.022Z"
}

🛡️ CORS

This service is protected by a CORS policy, which you can configure by setting the TRUSTED_ORIGINS environment variable.

When you use the API, keep in mind what roles these headers play:

| "Origin:" | "Referrer:"* | Result | | --------------------------------------------------------- | ------------------------------ | ------ | | Defined and API BEAVUCK_TIME_TRUSTED_ORIGINS set to * | Whatever | ✅ | | Trusted | Whatever | ✅ | | Same as this API's host | Whatever | ✅ | | Not defined | Same as this API's host | ✅ | | Defined and not trusted | Whatever | 🛑 | | Not defined | Not defined | 🛑 | | Not defined or not trusted | Different from this API's host | 🛑 |

*AKA Referer (sic).

📚 Use cases

Batch POSTs

Suppose you're creating timestamped entities in your app, and you want to send them in a batch to your API. Your API knows the current time when it gets the request, but not the creation time of each entity.

sequenceDiagram
    participant 📱 Client
    participant 🖥 Core API
    📱 Client->>🖥 Core API: POST /entities [{...}, {...}, {...}]

And querying your core API for the current time for each entity is a waste of resources -- that's why you're batching the operation in the first place.

sequenceDiagram
    participant 📱 Client
    participant 🖥 Core API
    📱 Client->>🖥 Core API: GET /now
    🖥 Core API->>📱 Client: {"now": "2024-06-15T12:35:48.022Z"}
    📱 Client->>🖥 Core API: GET /now
    🖥 Core API->>📱 Client: {"now": "2024-06-15T12:35:49.071Z"}
    📱 Client->>🖥 Core API: GET /now
    🖥 Core API->>📱 Client: {"now": "2024-06-15T12:35:49.243Z"}
    📱 Client->>🖥 Core API: POST /entities [{...}, {...}, {...}]

So you can use this service to get the current time whenever you need it, and use that as the creation time for each entity.

sequenceDiagram
    participant 📱 Client
    participant 🕒 Time
    participant 🖥 Core API
    📱 Client->>🕒 Time: GET /now
    🕒 Time->>📱 Client: {"now": "2024-06-15T12:35:48.022Z"}
    📱 Client->>🕒 Time: GET /now
    🕒 Time->>📱 Client: {"now": "2024-06-15T12:35:49.071Z"}
    📱 Client->>🕒 Time: GET /now
    🕒 Time->>📱 Client: {"now": "2024-06-15T12:35:49.243Z"}
    📱 Client->>🖥 Core API: POST /entities [{...}, {...}, {...}]

📜 License

Have at it.

This project uses the Unlicense. See the UNLICENSE file for details.