Update many heroku Apps with one Rails Project - heroku-postgres

I'd like know if is possible to have a single Rails App, where i have many different clients using this same App, where every single client have your own PostGreSQL DB in Heroku, so we have the same project to be updated for all this clients when i do the pushs to Heroku.
Do you know if it's possible to be done?
And how to ignore the database.yml file in updates, because every single client has your own DB.
Thanks!

You can but you probably shouldn't!
You can attach any number of Heroku Postgres instances to a Heroku app. You'll see that each instance you create adds a connection string to the list of environment variables - listed under the App's settings tab.
You can map the key string to a customer - via some unique identifier. You would then need to have an interceptor to bind the connection to the relevant database - or chose the relevant connect from a pre-bound list - and add it into the request context for each request.
It's a messy approach and not recommended. What would be slightly less messy is if you created a separate schema per customer instead. This way you bind to a single database instance and retain your database.yml config. But, each customer has their own dedicated schema. However, these are more architectural concerns that Heroku capabilities. From a Heroku perspective, both multi-database and mutli-schema approach is possible.
It should be noted that neither approach would give you any more referential integrity at the application logic level than standard roles and permissions with adequate auth mechanisms... All schemas and/or databases will be visible to the same application regardless of its separation at the database level. So, really there's little tangible benefit to it.

Related

How do you create an API server based on data from an existing Rails/Postgres web application?

I have an existing web application that's developed with Ruby on Rails and PostgreSQL. I need to create a mobile application (and possibly a separate web application) using the data from that web application, so I'm looking to create an API server. Is it possible to do this without altering the source code from the original Rails/Postgres web application?
Any ideas on the best way to do this? Or can someone point me in the right direction on what to research?
To connect a new application hosted on Heroku to a PostgreSQL database hosted on Heroku just push your new application to Heroku as normal.
Then, under Settings on your new application dashboard, go into Config Variables and add a new config for DATABASE_URL. Put the value of the url for your existing database.
Your new application will need to be under the same account as your existing application. Heroku doesn't allow you to connect across accounts.
You probably want to take a look at this question for additional details.
Sounds like essentially you want to have two applications connecting to the same database offering the same methods, but respond in different formats (html vs, for example, json). One way of doing that relatively easily might be pushing another api only Rails app to heroku that connects to the same Postgres database (which was mentioned in the comments), but you would have to figure out how to handle authentication differently for your API end points. This depends on whether you are exposing these end points to the public or to something like a mobile front-end. You may want to switch to token-based authentication if you were formerly using sessions on the web-app. Once you implement secure authenticatoin for your api routes, all you have to do is make sure your methods, instead of rendering erb or haml templates, are returning raw data consumable by your intended client.

Database encryption options for Ruby on Rails hosted on Heroku

One of the clients I'm working with is requesting that I encrypt my database. The problem is, none of my other clients need or care about this.
I am wondering two things:
How costly (performance) is it to encrypt my entire database? I.e. how much slower will my read / writes be?
Is there anyway I can provision a small separate DB, or segment my current DB on Heroku and host that one specific client's data (wherein their data is fully encrypted).
Thanks!
Ringo

How to secure the content inside a production DB for a RoR web application

I have outsourced the development of a web application based on RoR and hosted on heruko. I have three types of users of this application, the developers, the content generators, and customers. I want developers to be able to create tables and/or change DB schema only. And i want content generators to be able to access the content of the DB (direct DB access or through the website).
my question:
How can i block developers from being able to access the DB content at the database engine level? i can add the developer as a customer of the site and they can have access to limited content, and this is fine. but how can i protect my DB content from someone copying it all over?
because i outsourced the development and because there is not contract between me and the developer i want to ensure that my IP is protected. what is the best way to do this ?
Please try to target your questions to one specific question.
Having said that, my answers would be:
Q) How can i block developers from being able to access the DB content at the database engine level?
A) Just don't have to give them access to the production server on heroku. That's the beauty of rails and migrations. You don't need access to the database server, you can make changes through migrations, but the data is separate.
Q) How can i protect my DB content from someone copying it all over?
A) Don't give out access, backup up your database, consider if heroku is the right choice.
Q) I want to ensure that my IP is protected. what is the best way to do this ?
A) Have really good security policies and practices such as strong passwords and changing them frequently, make sure all workers sign clear contracts for any period that they work, employ a good lawyer to review contracts.

How to migrate multiple users' Access db's to one single SQLServer db

UPDATED 2010-11-25
A legacy stand-alone application (A1) is being re-created as a web application (A2).
A1 is written in Delphi 7 and uses a MS Access database to store the data. A1 has been distributed to ~1000 active users that we have no control over during the build of A2.
The database has ~50 tables, some which contain user data, some which contain template data (which does not need to be copied); 3-4 of these user tables are larger (<5000 records), the rest is small (<100).
Once A2 is 'live', users of A1 should be able to migrate to A2. I'm looking for a comparison of scenario's to do so.
One option is to develop a stand-alone 'update' tool for these users, and have this update tool talk to the A2 database through webservices.
Another option is to allow users to upload their Access db (~15 MB) database to our server, run some kind of SSIS package (overnight, perhaps) to get this into A2 for that user, and delete the Access db afterward.
Am I missing options? Which option is 'best' (I understand this may be somewhat subjective, but hopefully the pro's and cons for the scenario's can at least be made clear).
I'll gladly make this a community wiki if so demanded.
UPDATE 2010-11-23: it has been suggested that a variant of scenario 1 would be to have the update tool/application talk directly to the production database. Is this feasible?
UPDATE 2011-11: By now, this has been taken into production. Users upload the .zip file the .mdb is in, which is unpacked and placed in a secure location. A nightly SSIS scheduled job comes along and moves the data to staging tables, which are then moved into production through SP's.
I would lean toward uploading the complete database and running the conversion on the server.
In either case you need to write a conversion program. The real questions is how much of the conversion you deploy and run on the customers' computers. I would keep that part as simple as possible, i.e. just the upload. That way if you find any bugs or unexpected data during the conversion you can simply update the server and not need to re-deploy your conversion program.
The total amount of data you are talking about is not too large to upload, and it sounds like the majority of it would need to be uploaded in any case.
If you install a conversion program locally it would need a way to recover from a conversion that stopped part way through. That can be a lot more complicated than simply restarting an upload of the access database.
Also you don't indicate there would be any need for the web services after the conversions are done. The effort to put those services together, and keep them running and secure during the conversions would be far more than a simple upload application or web form.
Another factor is how quickly your customers would convert. If some of them will run the current application for some time period you may need to update your conversion application as the server database changes over time. If you upload the database and run the conversion on the server then only the server conversion program would need to be updated. There would not be any risk of a customer downloading the conversion program but not running it until after the server databases were updated.
We have a similar case where we choose to run the conversion on the server. We built a web page for the user to upload their files. In that case there is nothing to deploy for the new application. The only downside we found is getting the user to select the correct file. If you use a web form for the upload you can't pre-select file name for the user because of security restrictions. In our case we knew where the file was located but the customers did not. We provide directions on the upload page for the users to help them out. You could avoid this by writing a small desktop application to perform the upload for the users.
The only downside I see to writing a server based conversion is some of your template data will be uploaded that is un-needed. That is a small amount of data anyway.
Server Pros:
- No need to re-deploy the conversion due to bugs, unexpected data, or changes to the server database
- Easier to secure (possibly), there is only one access point - the upload. Of course you are accepting customer data in the form of an access database so you still can't trust anything in it.
Server Cons:
- Upload un-needed template data
Desktop Pros:
- ? I'm having trouble coming up with any
Desktop Cons:
- May need multiple versions deployed
As to talking to a server database directly. I have one application that talks to a hosted database directly to avoid creating web services. It works OK, but if given the chance I would not take that route again. The internet is dropped on a regular basis and the SQL Providers do not recover very well. We have trained our clients just to try again when that happens. We did this to avoid creating web services for our desktop application. We just reference the IP address in the server connection string. There is an entire list of security reasons not to take this route - we were comfortable with our security setup and possible risks. In the end the trade off of using the desktop application with no modifications was not worth having an unstable product.
Since a new database server to be likely one the standard database engines in the industry, why not consider linking the access application to this database server? That way you can simply send your data up to sql server that way.
I'm not really sure why you'd consider even suggest using a set of web services to a database engine when access supports an ODBC link to that database engine. So one potential upgrade path would be to simply issue a new application in access that has to be placed in the same directory as to where their current existing data file (and application) is now. Then on startup this application can simply RE link all of its tables to your existing database, plus come with a pre link set of tables to the database server. This is going to be far less work in building up some type of web services approach. I suppose part of this centers around where the database servers going to be hosted, but in most cases perhaps during the migration period, you have the database server running somewhere where everyone can get access to it. And a good many web providers allow external links to their database now.
It's also not clear that on the database server system you're going to create separate databases for each one, or as you suggest in your title it's all going to be placed into one database. Since is going to be placed into one database, then during the upsizing, an additional column that identifies the user location or however you plan to distinguish each database will be added during this upsizing process to distinguish each user set of data.
How easy this type of migration be will depend on the schema and database layout that the developers are using for the new system. Hopefully and obviously it has provisions for each user or location or however you plan to distinguish each individual user of the system. So, I don't suggest web services, but do suggest linking tables from the Access application to the instance of SQL server (or whatever server you run).
How best to do this will depend on the referential integrity and business rules that must be enforced, if there are any. For example, is there the possibility of duplicates when the databases are merged? I gather they are being merged from your somewhat cryptic statement: "And yes, one database for all, aspnet membership for user id's".
If you have no control of the 1000+ users of A1, how are you going to get them all to convert to A2?
Have you considered giving them an SQL Server Express DB to upgrade to, and letting them host the Web App on their own servers?

Rails Subdomain Clustering

I am about to be writing a Ruby on Rails app which will use sub-domains to authenticate users. We will have two types of accounts:
user accounts
domain accounts
Users will thus be able to belong to multiple domain accounts using the same credentials. I hope to have the ability for a domain account administrator to be able to search for particular users and add them to their domain.
In addition to simply creating a domain account in the database, I want to setup an actual account on the machine (linux-based) so that users can drop files into a special directory and we can run some scripts to import that new data. Alternatively, I may write a client/server script to make this process easier.
All of this I believe I can do, however, as soon as the project attains a certain number of domain accounts, it will be necessary to figure out how to cluster the domain accounts appropriately so that we can have multiple machines.
From a database standpoint, this is fairly easy and there are lots of tutorials on how to cluster MySQL or whichever SQL server I decide to use. So my question really pertains more to machine accounts as well as how to cluster a Rails app.
If you want a comparison, think of this project like GitHub or Beanstalk but with data that isn't source control related.
Does anybody have any experience with this or know of any really good articles/books to get me started?
Thanks very much!
I suggest you look at using one of the PAM modules that lets you do account authentication against a SQL database. That way you just add the domain account to the SQL database and you get UNIX accounts (on all your servers) automagically, for free. So the clustering should just happen for free too...

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