Rails same app with different databases - ruby-on-rails

I'm building a report app in Rails for a current desktop app. The app is kind of pos/accounting.
So at the moment there are different clients with the desktop app installed at shop or office. Each one has its own mysql database.
I am now planning how to setup the server, most probably heroku.
Given that I will keep the databases for each client separated, I'm trying to understand the best path to follow.
Another thing to consider is that there will be different version of the app, i.e. restaurant, bar, shop etc.. Different versions will use the same database. I'll just need to change some controller and view. Most probably I'll handle this using namespace.
For a client(company) multiple users will have access to the app.
The solution I thought is to create a database table company and add a column company to users table.
Things that could change from a client to another:
call different images from assets such as logo
there might be custom views or even controller if a client requests some customization
use different database
domain possibly, but that's not that important wouldn't a be a big deal to use the same
Then based on user.company show a different logo or any other required image, render a view instead of another, at login connect to the proper database.
I don't know yet how to implement it, right now I'm still evaluating the best approach to follow. But this way maintenance/updates would be easy to manage even if maybe performance will be a bit lower and code harder to understand with possible customizations all together but that's acceptable.
Is this a reasonable solution or should I consider something different? Am I missing something important to consider?

Related

White label without code duplication?

I have a technical question I'm not sure about.
Right now I have a product / web app (rails application) that I white label to other companies. I host the white label and everything I'm just wondering how to get out of this viscous cycle of having to duplicate all my code.
If I make a change to an API on one I have to do it to the other. I'm not sure how to get around this but I think it is important.
I've thought about building a core API which will route requests to different white labels servers but I'm not sure this is the best option.
Any help offered is greatly appreciated!
It sounds as if you clone your app each time you add a new company, whereas the proper solution would be to have one app that serves somewhat different data depending on the current company.
You can use the Apartment gem if you wish to use different dbs for different companies (sort of, check docs for more details), but you need to make sure your db can handle multiple tables (PostgreSQL can't). Or you can use Acts As Tenant if you wish to scope records to a specific company.
My suggestion is to go with Acts As Tenant, as most dbs are doing well with multiple rows, but not so well with multiple tables.

Rails, handle two sites with different url and design but with the same db

I'm looking for the best way to solve a problem.
At this moment I have a site for a customer, example.domain.com
My customer ask to create another website with some changes in design, but the contents are the same of the first website. I don't want to duplicate the website, because every feature I add to the site A must be deployed also to site B, and I'm looking a smart way to handle the situation.
I need to keep two different domains and I need also custom mailers and other small tweaks in the controllers (and maybe in some models).
My idea is to put in application controller a before filter like this
before_action :detect_domain
private
def detect_domain
case request.env['HTTP_HOST']
when "example.domain.com"
request.variant = :host1
when "example1.domain.com"
request.variant = :host2
end
end
Then I use the variant with some conditional to choose the mailer, to customize the views and to apply some code changes.
Any other idea?
Using a before filter and a per-request variable like your proposal will work, with a couple caveats that I'll mention below. I'd recommend a tool like the request_store gem to actually store the per-request value of which "skin" is selected.
Now, for the caveats. First, the main problem with per-request variables is that your Rails app does not always exist in the context of a request. Background jobs and console sessions operate outside of the usual request/response flow of your app. You will need to think about what happens when your models or other non-controller/view code is executed when that variable isn't set. I would suggest simply not having your models depend on RequestStore at all -- have the controllers pass any request-specific information down into the models, if needed.
Secondly, it's not clear from your description if you want any data or logical separation between the two domains, or if you just want different look-and-feels. If the former, you might consider the apartment gem, which aims to make database multi-tenancy easier.
EDIT: I also want to mention that, as an alternative to the multi-tenant solution above, you also have the option of a multi-instance solution. Wherein, you use an environment variable to indicate which version of the site should be displayed, and spin up multiple instances of your app (either on the same server with a reverse proxy, or on separate servers with separate DNS entries or a reverse proxy). The downside is increased infrastructure costs, but the context problem I mentioned above no longer exists (everything always has access to environment variables).

Multisite application in Rails (like shopify.com)

I would like create web app like shopify.com.
User can pickup subdomain(or domain), theme and have own store.
How can I do this?
Create main application, deploy it automatically like new standalone version and update it via git?
I'm using Rails 3.
Thanks for your advice.
Based on replies:
When I choose to use only one application (without multiple instances) and give user his subdomain, it will looks like their own website. But everything will be in one database (It's good idea?). And how can I have multiple themes in Rails app?
Take a look at LocomotiveCMS, specifically the routing system. Locomotive actually hosts multiple sites inside a single rails application. It does this by inspecting the request URL when it comes in and setting the current_site variable with the site which is set up to handle the domain. Then the current_site is actually just an object which contains all the pages, contents, settings, etc. for the specific site being served up.
So to answer your question, I think a good solution is to give your rails app the ability to serve up multiple sites based on the domain. It's not that hard, and it seems less fragile to me than trying to automatically deploy new instances of an app.
So far I have understood, you want to let your users have their own subdomain, different theme but the functionality would be same right. Users just need to have a feel of something of their own.
Well definitely, you need to have a single application that supports multiple subdomains.
A quick googling gave me [ http://37signals.com/svn/posts/1512-how-to-do-basecamp-style-subdomains-in-rails ]. May be you can get some insights from here.
For example if your service is http://www.myfi.com, a brief idea can be:
When a customer is registering, you should let him choose his subdomain. And the newly created account will be associated with this subdomain with a url. Say, http://customer1.myfi.com.
You should register for domain *.myfi.com so that anyone in the world hit with anysubdomain.myfi.com, it comes in your application.
Then from the url part, you should identify the subdomain (customer1) that is being used, and need to set that in session.
Now when someone will try to login, you must verify the account in the context of that subdomain's account.
In fact, all following actions need to be handled in the context of the subdomain's account.
Just tried the gather a glimpse of the implementation here. If you have confusion about something specific, share that also.
Edit:
Whenever you are thinking about multiple theme, you must have simple design which is completely driven by css and js. The app/view files should contain only content and HTML nodes with class names or ids.
Generally a UI designer can put more helpful ideas about how to make such theming mechanism. But all I can feel is, based on the chosen theme by customer, you have to load different css and js.
Actually the strategies can be indefinitely sophisticated and scalable, but its always wise to start with something easy. Then ideas will automatically evolve into better ones.

Multi domain rails app. How to intelligently use MVC?

Background:
We have app a, b, and plan to add more apps into this same application. The apps are similar enough they could share many views, assets, and actions. Currently a,b live in a single rails app(2.3.10). c will be similar enough that it could also be in this rails app.
The problem:
As we continue to add more apps to this one app, there's going to be too much case logic that the app will soon become a nightmare to maintain. There will also be potential namespace issues. However, the apps are very similar in function and layout, it also makes sense to keep them in one app so that it's one app to maintain(since roughly 50% of site look/functionality will be shared).
What we are trying to do is keep this as clean as possible so it's easy for multiple teams to work on and easy to maintain.
Some things we've thought about/are trying:
Engines. Make each app an engine. This would let us base routes on the domain. It also allows us to pull out controllers, models and views for the specific app. This solution does not seem ideal as we won't be reusing the apps any time soon. And explicitly stating the host in the routes doesn't seem right.
Skinning/themes. The auth logic would be different between the apps. Each user model would be different. So it's not just a skinning problem.
In app/view add folder sitea for sitea views, siteb for siteb views and so on. Do the same for controllers and models. This is still pretty messy and since it didn't follow naming conventions, it did not work with rails so nicely and made much of the code messier.
Making another rails app. We just didn't want to maintain the same controller or view in 2 apps if they are identical.
What we want to do is make the app intelligently use a controller based on the host. So there would be a sessions controller for each app, and perhaps some parent session controller for shared logic(not needed now). In each of these session controllers, it handles authentication for that specific app. So if the domain is a.mysite.com, it would use session controller for app a and know to use app a's views,models,controllers. And if the domain is b.mysite, it would use the session controller for b. And there would be a user model for a and user model for b, which also would be determined by the domain.
Does anyone have any suggestions or experience with this situation? And ideally using rails 2.3.x as updating to rails 3 isn't an option right now.
Devise does exactly this. You would do well to check out its architecture and apply that architecture to your own case.
You will have multiple separate Rails applications. The shared code will be a separate project, perhaps distributed as a gem or at least a separate Git repository. The shared code will include many controller actions and many view templates that are there to be sensible defaults, and which will be overridden in some apps but not in others.
All the custom code for application A will belong in a project solely devoted to containing the custom code for application A. It will be its own fully-functioning Rails application and will depend heavily on the majority of the sensible defaults provided by the shared code in the shared-code project.
I've used the theme support plugin before and dynamically set the theme based on the request uri:
http://mattmccray.com/svn/rails/plugins/theme_support
It will probably need some work to support Rails 2.3.
Update: Looks like there's a rewrite: https://github.com/dasil003/rails-multisite
Sounds like you want to make the 'base' app a plugin and use that in each of your site apps. You can use something like svn-extern so it's automatically updated whenever something changes.

What is the best strategy to combine IntrAnet and Web-exposed website?

I was wondering if somebody has some insight on this issue.
A little background:
We've been using Rails to migrate from an old dBase and Visual Basic based system
to build internal company IntrAnet that does things like label printing,
invetory control, shipping, etc - basically an ERP
The Dilemma
Right now we need to replace an old customer-facing website that was done in Java, that
would connect to our internal system for our clients to use. We want to be able to pull information like inventory, order placement, account statements from our internal system and expose it to site live. The reason is that we take orders on the website, through fax & phone and sometimes we have walk-ins. So sometimes (very rarely thou) even a short delay in inventory update on our old Java site causes us to put an order on backorder, because we sell the same item to 2 customers within half an hour. It's usually fixed within one day but we want to avoid this in the future.
Actual Question
Does anyone have any suggestion on how to accomplish this in a better
way?
Here are three options that I see:
a) Build a separate Rails app on a web server, that will connect to the same DB that our internal app connects to.
+++ Pluses:Live data - same thing that our internal apps see, i.e. orders are created in real time, inventory is depleted right away
--- Minuses: Potential security risk, duplication of code - i.e. I need to duplicate all the controllers, models, views, etc. that deal with orders.
b) Build a separate Rails app on a web server, that will connect to a different DB from our internal app.
+++ Pluses: Less security exposure.
--- Minuses:Extra effort to sync web DB and internal DB (or using a web service like REST-API), extra code to handle inventory depletion and order # creation, duplication of code - i.e. I need to duplicate all the controllers, models, views, etc. that deal with orders.
c) Expose internal app to the web
+++ Pluses: all the problems from above eliminated. This is much "DRY"er method.
--- Minuses: A lot more security headaches. More complicated login systems - one for web & one for internal users using LDAP.
So any thoughts? Anyone had similar problem to solve? Please keep in mind that our company has limited resources - namely one developer that is dedicated to this. So this has to be one of those "right" and "smart" solutions, not "throw money/people/resources at this" solutions.
Thank you.
I would probably create separate controllers for the public site and use ActiveResource to pull data from you internal application. Take a look at
http://blog.rubybestpractices.com/posts/gregory/rails_modularity_1.html
http://api.rubyonrails.org/classes/ActiveResource/Base.html
Edit - fixed link and added api link
I would go for a. You should be able to create the controllers so that they are re-usable.
Internal users are as likely to duplicate data as external users.
It's likely that a public UI and an internal, for-the-staff, UI will need to be different. The data needs to be consistent so I would put quite a bit of effort into ensuring that there is exactly one, definitive database. So: one database two UIs?
Have a "service" layer that both UIs can use. If this was Java I would be pretty confident of getting the services done quickly. I wonder how easy it is in Ruby/Rails.
The best outcome would be that your existing Customer Java UI can be adapted to use the Rails service layer.
Assuming you trust your programmers to not accidentally expose things in the wrong place, the 'right' solution seems to me to have a single application, but two different sets of controllers and views, one for internal use, and one for public-facing. This will give you djna's idea of one database, two UIs.
As you say having two separate databases is going to involve a lot of duplication, as well as the problem of replication.
It doesn't make sense to me to have two totally separate apps using the same database; the ActiveRecord part of a Rails app is an abstraction of the database in Ruby code, therefore having two abstractions for a single database seems a bit wrong.
You can also then have common business rules in your models, to avoid code duplication across the two versions of the site.
If you don't completely trust your programmers, then Mike's ActiveResource approach is pretty good - it would make it a lot harder to expose things by accident (although ActiveResource is a lot less flexible and feature rich than ActiveRecord)
What version of Rails are you using? Since version 2.3 Rails Engines is included, this allows to share common code (models/views/controllers) in a Rails plugin.
See the Railscast for a short introduction.
I use it too. I have developed three applications for different clients, but with all the shared code in a plugin.

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