A simple Express App to be used as API endpoint to facilitate query of Astronomy Picture of the Day

• This express app fetches data from a local PostgreSQL database, which is already set up and inflated with data.
• It's listening at 0.0.0.0 in port number 8000.
• So that clients present in local network can access this express server easily by typing in IPAddress:PortNumber, which is allocated to that computer, which is running this app.
• It has two API endpoints, where it listens for incoming requests.
• If we query at /apod, we'll get a list of all available records in databse.
• Querying at /apodbydate/:date will result into receiving of Astronomy Picture of the Day, where the day is defined in Request Parameter date in form of YYYY-MM-DD.
• And ofcourse all the responses sent back from server, are JSON.
• Well if a record is not found for a certain date, then {"msg": "noRecord"} is sent back to client.
• If a date is not properly formatted, then {"msg": "badDate"} is sent back to client.
• In fetch_from_psql.js, I've created a Javascript Object which is imported in apod_server.js.
• So, there're two methods getAll() and getByDate() which pulls data from local PostgreSQL database.
• getAll() returns list of all records, where dates are descending.
• getByDate() returns only the APOD for a certain requested date.
• And that's it ;)

• To run this app on you computer first clone this repo.

  >> git clone https://github.com/itzmeanjan/apod_server.git

• Make sure you've latest version of NodeJS and NPM installed on your system.

• Download all project dependencies by running, which will download all dependencies by reading package.json.

  >> npm install

• Then run apod_server.js.

  >> node apod_server.js

• So the server is up and running now.

• To test, head to your browser, and type IPAddress:PortNumber/apod, and you see a lot of data.

• Here IPAddress is IP of your computer in localnetwork, which is running the express app.

• PortNumber can be anything greater than 1024. I set 8000, just put your choice.

So I've opened up another repo, which will help you in fetching Astronomy Picture of the Day from NASA.

Last but not least, thanks to NASA for providing us with such a great service(NASA APOD), which could be used as a great resource for learning thing related to Astronomy. Thanks to NodeJS, NPM and ExpressJS for providing such a great ecosystem, which has made it really easy to write web apps/ API endpoints, with few lines of code. Finally thanks to PostgreSQL.

Hope it was helpful :)