Suppose there is a deployed, public website/web service. They say it is an instance of an open source codebase. Can they prove it to me?
For example, take the useful www.s3auth.com, an HTTP auth gateway for S3 that lets you password protect static sites hosted on S3 (thanks to #yegor256). Yegor graciously open-sourced the service to assuage privacy concerns:
I made this software open source mostly to guarantee to my users that the server doesn't store their private data anywhere, but rather acts only as a pass-through service. As a result, the software is on GitHub.
Can he somehow prove to users that www.s3auth.com actually uses the exact codebase on Github?
Short answer
In the general case: No, without a complete and external audit of the software, hardware and network infrastructure during a specific period of time
Explanation
Ensure that a sofware is according an specification it is not at all a trivial task. Note that even the requirement actually uses the exact codebase on Github is not clear:
- Includes any part of the repository
- Includes a full tag
- Includes a full tag at a point of time
- Includes a full tag at a point of time and uses some functionality
- Includes a full tag at a point in time and uses a significant part of the functionality
- Includes a full tag at a point in time, uses a significant portion of the functionality, and there is no additional function that substantially modifies the behavior
- Includes a full tag at a point of time, uses a significant part of the functionality, and there is no additional function
- etc
An auditor should check:
the code to ensure that the requirement is acomplished
the build process to verify that the deliverable is the expected and does not include or remove parts
The hardware infraestructure to ensure the software is deployed, not altered an used as is
The network infraestructure to verify the deployed version is really the same that the users are getting
Any change on the code or infraestructure will invalidate the audit results
The auditor should be external to ensure independence and should in turn be audited by a regulatory body that certifies that it is capable of performing the process
I think I am beating around the bush. .I want to illustrate that assert that a software meets a specification it is difficult, expensive, and sometimes not useful. Of course, this process it is not needed if both parties agree on something simpler
This kind of audits exists in the real world, especially in the world of security. For example FIPS 140 or Common Criteria evaluations certifies that Hardware Security Modules or even software packages meets some security requirements. I know also some trusted certifiers that prove that a site shows a specific content at a point of time (usually applied to e-goverment)
Imagine a very big gwt project of application. This is just a some form of scientific environment on the web. So for each user it stores the state of app and there is nothing related to browser history or bookmarks. History is something that can't even be applied to application itself (like CAD systems or whatever, having no intuitive "back button"). We are considering whether to use or not modern Activities And Places along with MVP. What are the pro and cons of Activities and Places if history management doesn't have sense? Could this framework give some advantages in code maintaining and code's modularity comparing to traditional MVP+DI without any Places and Activities? Taking in account that app is going to provide and API for some form of plugins
Given that Places are only about navigation within the app (not necessarily tied to browser history, but still very similar), and Activities build on Places a a way to modularize and decouple building blocks of your UI, with a lifecycle tied to the Places, then I don't see any benefit in using them in your case.
N.B.: Activities and Places have absolutely nothing to do with MVP, it's all about navigation, as the official documentation says:
GWT 2.1 introduced a built-in framework for browser history management. The Activities and Places framework allows you to create bookmarkable URLs within your application, thus allowing the browser's back button and bookmarks to work as users expect. It builds on GWT's history mechanism and may be used in conjunction with MVP development, though not required.
Source:
https://developers.google.com/web-toolkit/doc/latest/DevGuideMvpActivitiesAndPlaces
I have several plugins and would like to create a nice update site to provide them. Some of them only contain core functionality (would not do anything, let's call them core-plugin) and others provide some functionality to the end user (they are dependent on the core plugins, let's call them useme-plugin).
now, I've created features for every useme-plugin. I included the corresponding plugin and set all dependencies (core-plugins).
these features, I've added to an update site.
When I try to install them now, I get complains that core-plugins are missing:
Cannot complete the install because one or more required items could not be found.
Software being installed: Useme-plugin 1.1.0.201108090928 (de.xxx.feature.feature.group 1.1.0.201108090928)
Missing requirement: Useme-plugin 1.1.0.201108090928 (de.xxx.feature.feature.group 1.1.0.201108090928) requires 'de.xxx.coreplugin 1.1.0' but it could not be found
Did I do anything wrong? I don't want to include the core-plugins into every useme-feature... Or do I have to do that? Can anybody help me to structure it correctly?
Features are ment to group related plug-ins that should be installed as a single unit on a target system. Thus you normally have a number of features for a non-trivial application:
the main feature with the base functionality of the application
a number of features for optional add-in functionality
a number of features with core functionality
a number of features with major collections of 3rd party plug-ins
Two or more features can include the same plug-in - the plug-in will still only exist in one instance on the target system. In special cases, several different versions of the same plug-in can even exist on the target system. In other cases where different features depends on different versions of the same plug-in, you have a conflict that must be resolved by the developer.
A feature can also include or depend other features, in which case, the depended-on features must be installed as well on the target system. Thus the main application feature depends on the needed core and 3rd party features and likewise for 3rd party features. The installation of the depended-on features usually happens automatically with p2. p2 is smart enough to only downloaded needed plug-ins when installing or updating...
At run-time, it does not matter how a specific plug-in ended up on the target system, which gives a number of options in your case.
When dividing plug-ins into features, you must primary consider the wanted applications on the target system and the wanted add-ins. It only gets really difficult when you have multiple applications or add-in that each use a sub-set of the core plug-ins or 3rd plug-ins.
You have not written whether you have a single application or a number of applications, so I assume you have a single application - it is rather easy to extend the idea to multiple applications that share a common set of plug-ins.
You can solve this problem in several different ways. The absolutely most simple solution is to make a single application feature and include the UI, core and 3rd party plug-ins in this - more or less as you suggest. This works fine if you just have a single product and don't expect to use the core plug-ins in other setups.
Often you divide your features to have core and UI features. Most often because the UI functionality is divided into different features to allow the end-user only to install the needed functionality.
So in you case, you can also have two features: the core feature and the application feature, which then depends on the core feature.
Or you can have
the core feature
a UI functionality feature - that depends on the core feature
an RCP feature (from Eclipse)
and main application feature that depends on all the other features
There are plenty of ways to do this...
Basically my project is product based.
Once we developed a project and catch the multiple client and deploy the application based on their needs.
But We decided to put the new features and project dependent modules are as component.
Now my application got many number of customer.
Every customer needs a different features based on the component.
But we have centralized component for all client . we move the components additional feature to client specific folder and deploy.
My problem is , I am unable maintain the components features for multiple client.
My component feature code is increased and I am unable to track the client features.
Is there any solution for maintaining the multiple component features for multiple client ?
I've worked for a couple of companies in a similar space - product software but very heavily customised.
Essentially there is a decision the company needs to make - are you a product company (that is you ship broadly the same to every client) or are you a bespoke company. At the moment it sounds like they're between two stools and wanting the economies of being a product company with the ability to meet specific client demands the way a bespoke software company can.
Assuming the company wants to be a product software company, unless there are specific technical reasons why you can't, you need to move to a single code base with the modifications for each customer being handled through customisable options (i.e. flags saying how this particular situation is being handled, whether this feature is available and so on).
These can be set at run time (so they can be changed as the client wants - think options in Word or Excel), or build time (so code is included / excluded when you do the build), but the key things is that every client has to be pulled from the same code base.
But this needs to be agreed with the business as it limits what they can sell - every change they sell has to fit into an overall vision which can be accommodated by the single product.
The alternative is that you're essentially producing bespoke software for each client (that is coded specifically for what they want) but using many common libraries. That's fine and allows you to produce something which is exactly what they want but in the end it is going to be more work and the business needs to understand and cost for that.
We actually do a bit of both - there is a server product which is identical for all clients, and then web and mobile clients which are specific to them (in the case of mobile you can't have lots of dead code on the device - the web stuff is historic and will be moving to a standard product for all clients).
Good luck though, it's a difficult problem with no easy solution.
You are essentially talking about software product lines (SPLs): variations from a common base. Since you already package your features as components, you need a specialized tool to manage such variations.
You can then build a complete custom application based on a configuration that is unique to any given customer. Easier said than done, of course.
A model-driven software development(MDSD) approach can help a lot on this task. One such system that can support this development setup is ABSE, an emerging MDSD approach that among other things, can implement a software product line (info at http://www.abse.info - Disclaimer: I am the ABSE project lead). There is no product yet though. An alpha preview is coming.
Again, I know some companies that, using an MDSD coupled with code generation, have achieved what I understand you want: products that are half pre-packaged, half custom.
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We have written a software package for a particular niche industry. This package has been pretty successful, to the extent that we have signed up several different clients in the industry, who use us as a hosted solution provider, and many others are knocking on our doors. If we achieve the kind of success that we're aiming for, we will have literally hundreds of clients, each with their own web site hosted on our servers.
Trouble is, each client comes in with their own little customizations and tweaks that they need for their own local circumstances and conditions, often (but not always) based on local state or even county legislation or bureaucracy. So while probably 90-95% of the system is the same across all clients, we're going to have to build and support these little customizations.
Moreover, the system is still very much a work in progress. There are enhancements and bug fixes happening continually on the core system that need to be applied across all clients.
We are writing code in .NET (ASP, C#), MS-SQL 2005 is our DB server, and we're using SourceGear Vault as our source control system. I have worked with branching in Vault before, and it's great if you only need to keep 2 or 3 branches synchronized - but we're looking at maintaining hundreds of branches, which is just unthinkable.
My question is: How do you recommend we manage all this?
I expect answers will be addressing things like object architecture, web server architecture, source control management, developer teams etc. I have a few ideas of my own, but I have no real experience in managing something like this, and I'd really appreciate hearing from people who have done this sort of thing before.
Thanks!
I would recommend against maintaining separate code branches per customer. This is a nightmare to maintain working code against your Core.
I do recommend you do implement the Strategy Pattern and cover your "customer customizations" with automated tests (e.g. Unit & Functional) whenever you are changing your Core.
UPDATE:
I recommend that before you get too many customers, you need to establish a system of creating and updating each of their websites. How involved you get is going to be balanced by your current revenue stream of course, but you should have an end in mind.
For example, when you just signed up Customer X (hopefully all via the web), their website will be created in XX minutes and send the customer an email stating it's ready.
You definitely want to setup a Continuous Integration (CI) environment. TeamCity is a great tool, and free.
With this in place, you'll be able to check your updates in a staging environment and can then apply those patches across your production instances.
Bottom Line: Once you get over a handful of customers, you need to start thinking about automating your operations and your deployment as yet another application to itself.
UPDATE: This post highlights the negative effects of branching per customer.
Our software has very similar requirements and I've picked up a few things over the years.
First of all, such customizations will cost you both in the short and long-term. If you have control over it, place some checks and balances such that sales & marketing do not over-zealously sell customizations.
I agree with the other posters that say NOT to use source control to manage this. It should be built into the project architecture wherever possible. When I first began working for my current employer, source control was being used for this and it quickly became a nightmare.
We use a separate database for each client, mainly because for many of our clients, the law or the client themselves require it due to privacy concerns, etc...
I would say that the business logic differences have probably been the least difficult part of the experience for us (your mileage may vary depending on the nature of the customizations required). For us, most variations in business logic can be broken down into a set of configuration values which we store in an xml file that is modified upon deployment (if machine specific) or stored in a client-specific folder and kept in source control (explained below). The business logic obtains these values at runtime and adjusts its execution appropriately. You can use this in concert with various strategy and factory patterns as well -- config fields can contain names of strategies etc... . Also, unit testing can be used to verify that you haven't broken things for other clients when you make changes. Currently, adding most new clients to the system involves simply mixing/matching the appropriate config values (as far as business logic is concerned).
More of a problem for us is managing the content of the site itself including the pages/style sheets/text strings/images, all of which our clients often want customized. The current approach that I've taken for this is to create a folder tree for each client that mirrors the main site - this tree is rooted at a folder named "custom" that is located in the main site folder and deployed with the site. Content placed in the client-specific set of folders either overrides or merges with the default content (depending on file type). At runtime the correct file is chosen based on the current context (user, language, etc...). The site can be made to serve multiple clients this way. Efficiency may also be a concern - you can use caching, etc... to make it faster (I use a custom VirtualPathProvider). The largest problem we run into is the burden of visually testing all of these pages when we need to make changes. Basically, to be 100% sure you haven't broken something in a client's custom setup when you have changed a shared stylesheet, image, etc... you would have to visually inspect every single page after any significant design change. I've developed some "feel" over time as to what changes can be comfortably made without breaking things, but it's still not a foolproof system by any means.
In my case I also have no control other than offering my opinion over which visual/code customizations are sold so MANY more of them than I would like have been sold and implemented.
This is not something that you want to solve with source control management, but within the architecture of your application.
I would come up with some sort of plugin like architecture. Which plugins to use for which website would then become a configuration issue and not a source control issue.
This allows you to use branches, etc. for the stuff that they are intended for: parallel development of code between (or maybe even over) releases. Each plugin becomes a seperate project (or subproject) within your source code system. This also allows you to combine all plugins and your main application into one visual studio solution to help with dependency analisys etc.
Loosely coupling the various components in your application is the best way to go.
As mention before, source control does not sound like a good solution for your problem. To me it sounds that is better yo have a single code base using a multi-tenant architecture. This way you get a lot of benefits in terms of managing your application, load on the service, scalability, etc.
Our product using this approach and what we have is some (a lot) of core functionality that is the same for all clients, custom modules that are used by one or more clients and at the core a the "customization" is a simple workflow engine that uses different workflows for different clients, so each clients gets the core functionality, its own workflow(s) and some extended set of modules that are either client specific or generalized for more that one client.
Here's something to get you started on multi-tenancy architecture:
Multi-Tenant Data Architecture
SaaS database tenancy patterns
Without more info, such as types of client specific customization, one can only guess how deep or superficial the changes are. Some simple/standard approaches to consider:
If you can keep a central config specifying the uniqueness from client to client
If you can centralize the business rules to one class or group of classes
If you can store the business rules in the database and pull out based on client
If the business rules can all be DB/SQL based (each client having their own DB
Overall hard coding differences based on client name/id is very problematic, keeping different code bases per client is costly (think of the complete testing/retesting time required for the 90% that doesn't change)...I think more info is required to properly answer (give some specifics)
Layer the application. One of those layers contains customizations and should be able to be pulled out at any time without affect on the rest of the system. Application- and DB-level "triggers" (quoted because they may or many not employ actual DB triggers) that call customer-specific code or are parametrized with customer keys) are very helpful.
Core should never be customized, but you must layer it in somewhere, even if it is simplistic web filtering.
What we have is a a core datbase that has the functionality that all clients get. Then each client has a separate database that contains the customizations for that client. This is expensive in terms of maintenance. The other problem is that when two clients ask for a simliar functionality, it is often done differnetly by the two separate teams. There is currently little done to share custiomizations between clients and make common ones become part of the core application. Each client has their own application portal, so we don't have the worry about a change to one client affecting some other client.
Right now we are looking at changing to a process using a rules engine, but there is some concern that the perfomance won't be there for the number of records we need to be able to process. However, in your circumstances, this might be a viable alternative.
I've used some applications that offered the following customizations:
Web pages were configurable - we could drag fields out of view, position them where we wanted with our own name for the field label.
Add our own views or stored procedures and use them in: data grids (along with an update proc) and reports. Each client would need their own database.
Custom mapping of Excel files to import data into system.
Add our own calculated fields.
Ability to run custom scripts on forms during various events.
Identify our own custom fields.
If you clients are larger companies, you're almost going to need your own SDK, API's, etc.