Nodejs Database configuration based on accessed domain - node.js

I have two domains abc.com and xyz.com pointing to the same NodeJS server. Based on the domain I want to load the configuration that will persist for that domain i.e. for xyz.com I wanna connect to Database1 and for abc.com I wanna connect to Database2.
How do I go about doing this? Is it even possible or recommended to do so?
I started with loading the configuration on the first request by getting the hostname from req.hostname. Is there any better way to do this?

Multiple strategies -
1. Deploy the same code multiple times but on different ports.
Your reverse proxy sends the request to the correct server. I do this currently by hosting multiple ghost blogs on the same vps. One runs on port 3000, another on 3010.
Pros - Less fragile setup, easier scaling, application need not be aware of operational environment. If one domain comes under attack, the other is not automatically a casualty.
Cons - Might not be possible in resource constrained environments. Deployments can involve repetitive work.
2. Read the hostname
Great option if the feature set is pretty much the same but only the domain name changes. You read the configuration file as you stated depending on the hostname.
Pros - Easier deployment, great option for resource constrained environments.
Cons - Unnecessarily tight coupling, all domains will become unavailable in case of server errors, scaling could be an issue.
Personally, I prefer deploying on different ports unless and until the code requires depending on hostnames. If you are just building a product where some unique identifier needs to be present in the URL like mycompany.slack.com then using subdomains in dns might be a better idea.

Related

Architecting back-end and Front-end solution (nodeJS)

I have a single back-end running node/express providing API endpoints and 2 static (react) front-ends. The front-ends interact with the users and communicate with the back-end.
I need to use https through-out once enter production stage.
The front-ends will require their own domain names.
I’ve been thinking on the simplest way to have these configured and have come up with Option 1 (see diagram). Node.js API server running on one VPS and as the front-ends are static sites these can be loaded on separate servers (UPDATE- Mean't to say hosting providers) hence get their own domains. As an option, and I’m unsure if its needed, add cloudflare to the front-end to provide a layer of security.
This will allow front-ends to have separate domain names.
As this is a start-up project and doubt a large number of visitors, I’m wondering if the above is over-engineered and un-necessarily complicated.
So I’m considering Option 2 of hosting back-end api app and the two front-ends on the same linux vps. As the front-ends are static, I added the front-ends into the public folder of node.js. This allowed me to access the front-ends as http://serverIP:8080/siteA
As I want to access front-end as http://siteA.com I’m assuming I require a reverse proxy (nginX)
The questions to help me decide between the two options are:
For a start-up operation and given he above scenario which option is best ?
I understand that node.js requires a port number regardless to work, for the API I don’t mind having a port number (as its not applicable for end users i.e. http://10.20.30.40:3000), however the two front-ends require their own domain names (www.siteA.xom, www.siteB.com), therefore will I need to employ a reverse proxy (nginX) regardless if they are static sites or not ?
I’m concerned that someone could attack API end-points (http://10.20.30.40:3000). In this case, is it true with Option 2 is safer than 1 - that I could potentially block malicious direct API calls as all sites are hosted on the same VPS and the API can be easily be secured, this is not exposed to the outside world?
My developer once upon a time told me that option 1 is best as nginX adds un-needed complication, but not sure what he meant – hence my confusion, to be honest I don’t think he wanted to add nginX to the server.
I’m looking at a high-level guidance to get me on the right track. Thank
This is - as you have also doubted - unnecessarily complex, and incorrect in some cases. Here's a better (and widely used across the industry) design. I'm strongly recommending to drop the whole VM approach and go for a shared computing unit, unless you are using that machine for some other computation and utilizing it that way is saving your company a lot of money. I strongly doubt this is the case. Otherwise, you're just creating problems for yourself.
One of the most common mistakes that you can make when using Node.js is to host the static content through the public folder (for serious projects) Don't. Use a CDN instead. You'll get better telemetry depending on the CDN, redundancy, faster delivery, etc. If you aren't expecting high volumes of traffic and performance of delivering that static content isn't outrageously important at the moment, you can even go for a regular hosting server. I've done this with namecheap and GoDaddy before.
Use a direct node-js shared - or dedicated depending on size - hosting for your app and use CI/CD to deploy it. You can use CNAMEs to map whatever domain name you want to have your app on (ex: https://something.com) to map to the domain name of the cloud-hosting provider url for your app. I've used multiple things, Azure, Heroku, Namecheap for the apps and primarily Azure DevOps to manage the CI/CD pipeline, although Jenkins is super popular as well. I'd recommend Heroku - since it provides a super easy setup.
When designing any API on HTTP, you should assume people will call your API directly. See this answer for more details: How to prevent non-browser clients from sending requests to my server I'm not suggesting to put something like CloudFlare, but you may be overthinking it, look into your traffic first. Get it when you need it. As long as you have the right authentication / authorization mechanism in place, security of the API shouldn't be a big problem on these platforms. If you deploy it on one of these platforms, you won't have to deal with ports either. Unless you reach absolutely massive scale, it will definitely be cheaper for you operate with high-reliability this way.
You won't need to deal with nginx anymore.

Assign different url to diferent users

Am trying to create a web app with nodejs and this app will have a different profile for different users.
when a user sign up from "www.site.com/signup", it should create a personal url for user e.g "user_name.site.com"
What you are looking for is called a subdomain. Subdomains are not handled at the application level. You need to add an A record in your DNS for every subdomain. Usually this is done using the API provided by your domain provider (or wherever your nameservers are located). Then, you'll need to proxy each subdomain to your application using some other web server like Apache or nginx.
The solution depends on:
Who your domain provider is.
What web server you're using (if any). Apache, nginx, etc.
The OS of the server.
And probably a lot more depending on your specific use-case.
Essentially what you're looking for isn't quite straightforward, and will probably involve a ton of work to get right and stable. There's many ways you can do this and it really depends on the rest of your technology stack. Not much of this actually has anything to do with node.js.

Is it possible to set DNS records in Node.js?

I've discovered a couple Node.js modules that allow for checking DNS records for domains, but none that allow for changing and setting DNS records to update domains.
Is what I'm asking even possible? I'm just looking for a step in the right direction.
I am using DNS Made Easy for my DNS servers, if that helps.
I think it really depends on the DNS server you're using. There are some standardized ways to update DNS servers - see https://en.wikipedia.org/wiki/Dynamic_DNS, or if you're using a service like afraid.org, then they have a REST-ish/HTTP endpoint you can call to update DNS records. There's no reason you couldn't initiate that call from node.js. That said - if you're trying to do real DDNS, you might have to implement a more tricky protocol to get it to happen. Some DNS servers just read text files from the disk, so you could also build something that updates those files and the domain serial number and reloads the server when an update occurs. TL;DR: it's possible, but you might have to implement some tricky stuff to get it to work.

Folder Structure for Nodejs Multi Subdomain site

So i am building a website using NodeJS where i will use Nginx as a reverse proxy to my app/apps. I will be using jade and sharing some layouts between subdomain and displaying specific content according to subdomain. I am trying to figure out from alot of research the best method of structuring the app. Is the best way to run each subdomain as a separate app on the same server? Or can i link them as one app? Please share your ideas and suggestions so i can make a decision and begin my coding :)
The main issue with using the same domain across multiple apps is security in regards to cookies. If apps are independent, then you might want to ensure a vulnerability in one app would not necessarily affect your other apps.
Otherwise, with nginx, there is really no limitation on your setup, however you decide to go. You can use nginx to easily join or disjoin multiple domains and/or ports/servers, into whatever setup you wish.
Whether you decide to go with multiple domains or multiple paths on a single domain have more to do with what kinds of apps you have in mind, and how logically separate would they appear to be from one another. With the help of the rewrite directive, even if you make a "wrong" choice initially, if you do have a desire, you could always fix it later on (preserving all existing links flawlessly), pretty much without any ill effect.
I am running multiple web applications (totally separated in different folders and running on different ports) on server with nxinx as proxy for different subdomains. However, if you want to make more subdomains for one application, the best way should be to structure it by URL.
For example you have mysite.com/books but you want books.mysite.com to be go to domain for books. You make proxy in nginx configs to redirect traffic from mysite.com/books to books.mysite.com.

Best practice for mobile app service domain

We're developing a client-server game that communicates with our server in real time. During development we directed the client to the server's IP address directly.
Moving forward to release, we'd like to switch the target server IP to a domain name.
I'm looking for feedback whether we should use a sub-domain within our web-site main domain (say: server.mygame.com), or, setup a different domain for the game server (mygame-server.com).
If there is no difference either way I'd love to get feedback on that as well.
Thanks!
This question might be better asked at serverfault.com because it is not strictly related to programming...
Anyway, providing my opinion on your quesion: I'd go for a subdomain of a new game-related main domain.
Here's why: this should give you the most flexability for future changes, assuming the following thoughts:
A new domain especially for that game allows you to promote game information on the www. subdomain.
The game endpoint sits (for example) at api. which points to a different server than any of the websites (improves stability, allows different software for same ports, e.g. web servers).
You can add round-robin DNS load balancing (or any other load-balancing) later. This might be easier if this can be done on a spearate main domain.
You don't have to mess with the main company DNS entries for any game-related settings, improving the stability of both services (as they are separated).
If you might sell the game one day, and a different domain makes it easier to transfer all services and data.
Using a subdomain makes it easier in general because normally the second-level domains (like the A record for example.com) is handled by the DNS servers at a "lower" level in "DNS authority tree" (e.g. at you DNS provider), so it might be more difficult to add special features like load-balancing there.
So these are only some thoughts. Basically it should not matter which way you set up the DNS entries, but if one of the topics above applies (or otherwise sounds reasonable) then you might choose a subdomain on a new domain ;)

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