Which is better: Use the multi-tenant plugin or different environments? - grails

Which solution is easier to maintain: The Multi-Tenant Plugin (http://www.grails.org/plugin/multi-tenant), or creating a different environment (http://grails.org/doc/latest/guide/3.%20Configuration.html#3.2%20Environments) for each instance of an application which is essentially the same (with minor changes) for each company?

The answer depends on how your application runs, and how you plan to deploy it. If you can deploy multiple WAR files, one for each client, then using environments is a possible option. However, I would strongly urge you to "white label" your application manually, or use the multi-tenant plugin, as environments will get unwieldy quickly and does not support adding custom views/logic per customer, which invariably becomes a requirement.

Related

Share code/configurations/conventions/gems between Rails apps

THE PROBLEM
First a little bit of context: I am currently working as a freelancer, developping webapps using Ruby on Rails. Because I am working solo, the need to optimize my workflow is pretty important.
That's why I have always had the same question since I begun working with Rails:
How can I share code/configuration/conventions/tests between my apps?
More precisely, I want to share:
common gems that I always use, with their configuration
common integration tests, to ensure some conventions
common view helpers, test helpers, extensions to the core classes, javascript/sass partials
common files: .gitignore, git hooks, .eslintrc, configuration files of my CI etc
Some concrete examples of what I need in all my apps:
disable turbolinks by default, to add it later if need be
use javascript instead of coffeescript
use slim instead of ERB
install/configure capistrano
install a CSS framework (bootstrap, bourbon + neat + refills)
So far I don't really have the need to share models nor controllers.
I don't want to share behavior or functional components of the system itself, I am not looking for a micro-services architecture.
I have found that so far when creating new applications, all this setup work does take me a lot of time. Also, I would like to apply it retro-actively to existing apps when I add something new.
I have done quite a bit of research, but I haven't found a lot of answers. Many people are trying to share models, but few people seem to want to share a common ground between all their apps. Finding the right keywords may have been the problem though.
It seems to me that Rails is really good at DRY within an application, not so easy when trying to DRY between applications.
POSSIBLE SOLUTIONS
1 - Rails application template
The solution I am using right now, described in the Rails Application Templates guide, using the same API than the Rails generators described in the Creating and Customizing Rails Generators & Templates guide.
That's the solution used by Thoughtbot, with their popular suspenders gem. In the case of Thoughbot though, they have years of experience to draw from, have many employees and their common setup does not change that much.
Pros:
saves a lot of time when creating a new application
really nice API
Cons:
a lot of duplication: all the apps have the same common code, with the problem of this code getting out-of-sync
not retroactive: useless to add a common feature to already created apps
heavy maintenance work: my current workflow is to go through the git log of my apps once per month, and for each commit that could be common to all the apps I have, add it to the application template, and add it to the other apps manually
So far this solution is not that bad, because I only have two applications. But once I will have more, I will suffer from more and more overhead.
A better solution would be maybe to create a generator/rake task for every common new feature, to be able to apply it quickly to existing apps, and call it directly in the application template for new apps.
I haven't tried it though, and I am not really sure it will work. For example what if I want to propagate a one-line change in an existing common file in all the apps?
2 - Rails Engine
I have tinkered a bit with the Rails Engines to share code.
I have not understood from the Getting Started with Engines guide if I should better use a --full engine or a --mountable one for this specific purpose.
Pros:
once I update the gem version, all the changes are made available to the app
DRY: all the common code is in a unique place (the gem)
Cons:
the gems I would like to share are put in the *.gemspec file, which has not as many features as the Gemfile (from what I understand)
overhead caused by the need to update the version of the gem in all the apps, migrate to the new API of helpers, etc
no way to share non-rails files (.gitignore, git hooks, .eslintrc)
This solution has too many important shortcomings.
3 - Hybrid solution: Rails Application Template + Rails Engine
Maybe the best would actually to use both the above solutions.
In the gem share helpers and tests, in the rails template share the gems, their configuration/files and other files (for git, linters, etc)
It is indeed adding more complexity and overhead...
4 - Use git subtrees
Some people use git subtrees to share folders between multiple webapps.
Cons:
one has to share whole folders, not easy to share everything I would need, in their different target directories in the rails app
seems a bit "hacky" to me
Conclusion
Is there another solution than the ones I mentionned above?
What do you think would be the best way to do it?
How about having a blank "Master" rails app in the git somewhere. With all the settings and configurations you'd like to share. When creating a new app from scratch, you can merge the "Master" into it to apply the defaults. When you have an existing app, same thing, just merge and resolve conflicts as needed.This also gives you the ability to override the merged code if needed to.
Few things I can see wrong with this approach though:
Rails application name could cause a lot of headaches
Any updates could cause merge conflicts
I created a tool to deal with this when working in nodejs projects. But the tool is really just a command line tool so you should be able to use it.
https://github.com/tomasbjerre/dictator-builder
It is a concept with creating a dictator that dictates parts of your code base.

App for managing apps (architecture)

I know it's gonna be a very broad question and I'm pretty sure this is not anything new in todays world, but I really don't now where to start on this one.
I've started working on a rails-based service that would allow users to create, configure and manage their projects (basicaly copies of a single app with customization). The projects would be run on a subdomain with an option of connecting their own domain. (Quite similar to how SquareSpace and Wix and many other website building services handle their websites)
I want these projects to be as flexible and customizable as possible (including the visual design, some additional features etc) while maintaing ease of setup and updates for the codebase itself.
So the questions I start with:
Should each project be a separate app (basicaly a copy out of the
same repo) with its own configs, database, nginx and unicorn
configs, etc. or should I keep all in 1 app and differenciate them
with different configs and maybe databases and assets?
If it's better to keep everything separated...
... what's the best setup process (provided that I have basic configuration to start with)?
... how would I be able to update them all (with bugfixes, new features, performance improvements etc.) from one place?
If I keep all the projects in the same app...
... how should I manage the configuration concurency between projects?
... how do I separate the data and assets?
As always, I'd be grateful for any sufficient help I can get.
I have no experience building these kind of things and maybe there is an easy solution I'm not aware of. But my answer may give you some ideas/pointers to start with.
1) It's hard to give an accurate answer but based on the high personalization criteria and the "copies of a single app" you talk about, I would go for an architecture more PAAS-like than SAAS-like. So separated apps.
2.1) You may want to consider a setting using:
A main rails app, with a main webserver and a main nginx conf. A wildcard domain.
A bunch of dynamically managed docker containers. Each container is initialized from your single app, and then personalized by the user. User is associated to its containers through the main rails app. When a container is created from the main app, the main nginx config is updated (i.e. by adding a file in sites-enabled which define a new 'server' that bind the open port of the new container, and the right 'server_name').
Each contained rails app ship an unique and shared rails engine. The rails engine is shipped by adding the corresponding gem in the Gemfile so it can be updated.
2.2) You update the 'shared rails engine' gem. You can then run bundle install in each containers.
People interested in these kind of setups may consider tools like dokku and deis.
Consider a multi-tenant architecture. We've used it effectively for fleet-genius.com.
The following link provides a good overview of the architecture from a Rails point of view.
http://blog.elbowroomstudios.com/zero-to-multitenant-in-15-minutes-a-rails-walkthrough/

How can I deploy 2 or more Rails webapps using AWS OpsWork?

How can I have 2 or more Rails applications using AWS OpsWork?
When I'd deploy 2 apps with Opswork they get the same URL and redirect to the first app deployed.
How can I manage to have two separate apps, in one instance of OpsWork?
I've had a similar problem before - with two Node apps in the same stack.
One answer would be to create two separate OpsWorks stacks for the two Rails apps. This of course assumes they don't depend on the same resources (ie a shared database).
The second, harder, answer - and the one I took for my Node apps - is to create a custom layer and manually specify all the recipes that the built in Rails layer calls. If the built in Rails layer and your custom layer BOTH have ELBs AND the Rails sites are hosted on separate instances (port numbers may clash, dependig on which app server you're using) AND you make sure your application deploys in OpsWorks target only the correct boxes (don't want to install two Rails apps on the same server!)... well it should work out. (Or come close).
I don't think this is as easy as it sounds: I remember digging into a fair bit of Opsworks Chef cookbook code for some reason. I forget if that was because of this custom layer issue or because of another custom layer I wrote.

Large Rails suite architecture: combine three apps into one container app

Our Rails suite is comprised of three independent Rails apps:
JSON API (Rails app)
Admin dashboard (Rails app)
Shared data models (Rails engine)
Both the API and Admin dashboard require the shared data models engine in their Gemfiles. All models and custom classes are stored in the engine, and both apps make heavy use of the shared components. The API lives on one Heroku server, and the Admin dashboard lives on another separate Heroku server (two separate Heroku apps). Each use their own respective Postgres databases. All three apps have their own GIT repos.
The API database stores information pertinent to our public users, and the Admin database stores mostly statistical information for admin eyes only.
A caveat of the setup is that the Admin dashboard app has direct access to the API database, and vice-versa. I understand that this is bad practice and may not seem to make sense, but there was a reason for this (mainly because the Admin dashboard needed to access all records of certain API tables, and the use of a custom API to communicate over the wire was not feasible). A similar reason exists for the API-to-Admin database communication.
This setup works for our purposes, nothing is broken, and resources are allocated efficiently. However, productivity is beginning to suffer due to the slow and uncomfortable development process. An example: a change to the API is required. Chances are that the shared models engine needs a change and therefore a feature branch is needed in both repos. After committing and pushing, the Admin dashboard now contains an old version of the models engine (is behind by one patch version). The problem lies in trying to coordinate all three Rails apps, when only one app needs a change. Another problem is migrations. Since the models engine contains two different database connections, I must create the migration once in the models engine then create it again in the appropriate app (API or Admin).
My ideal setup would involve one large Rails container app with separate engines contained within. The separate engines would be: API, Admin, Models. Also, I’m beginning to think that using only one database might make things easier. I would also like to keep the API on its own server instance, and the Admin on a separate server. The reason for this is that the API is public facing (communicates with a public iOS app) and the Admin is used mainly as a CMS and reporting engine.
I am looking for solutions and advice from experience managing similar Rails / Heroku architectures. Specific questions:
Should I attempt to combine the three Rails apps into one container
app and use the engine approach?
Should I attempt to combine the two
databases into one database?
Is it possible to have one Rails
container app, and allocate different servers to different engines?
If I should keep all apps separate, is their an easier and more
productive way to implement new features and fixes on a daily basis?

Rails application architecture and common setup

So I am starting out on company project that will have several components:
At first...
Job list
Client profile creation and management
User administration and access (login, signup, roles, etc)
later...
Messaging
Schedule
Basic reporting
way later...
Deeper analysis and bi
I'm wondering if it makes sense for each bullet item to be its own rails project, self contained and modular (if that is indeed the case); or if it's just best for it to be in the same app. I could envision a situation where each module could operate so independently of each other that it wouldn't need the rest (except for the user funcionality) and another situation where all modules would be used together.
It seems like to me that many tasks can be handled with a lighter framework like Sinatra (and then situated physically under the rails app). It also seems like it would be a lot of overhead to have several rails apps running on a server. But I am not totally aware of all the pluses and minuses to operating each scenario.
I know this is kind of a general question that is bound to get a lot of "it depends" kind of responses (and rightfully so) I was looking for opinions/examples of how you setup this kind/your kind of project in rails. I am a quasi noob so be gentle.
Thanks in advance!
Generally speaking I would consider a website to be a suitable target for a Rails app. Each part of the app can have its own namespaces within the app, so the app has some structure internally, but they should all be one application. Consider things like sessions, where you want a user to login and use whatever features of the site you want. You want those sessions in one application without a user having to login to different sections.
Saying that, if there is complex or extended functionality that isn't part of the MVC architecture (say talking to an external API, data-mining etc), then you could offset that to a separate project and a include it as a Gem in your application. You would still have one main Rails application that includes those Gems.
You might also want to bundle together a section of your project into a reusable Rails engine that can be loaded into multiple projects. For example, Devise handles user login and management. It is a Rails engine, bundled as a Gem, that you include in your project.
Another example from Meducation (one of my sites). I'm in the process of extracting our email tracking system out into its own Rails engine as I feel its functionality sits alongside Meducation and is not a core part of it. I can then use it in other projects as well.
In your specific example, I think your requirements fit fine in one Rails application.

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