using window.env variables to show/hide React component - html

Is it good idea to show/hide React component using window.env
for example we have feature which we are not ready to release yet,so we are thinking of hiding it using window.env.FEATURE_ENABLED=0 (these vars will be picked by api call to service that serves bundle to browser)
But,I am thinking its risky since user can look at windows.env and set window.env.FEATURE_ENABLED=1 and start seeing the workflow which we intend to hide.
Could anyone please provide their take on this.

Yes, it could potentially be risky for the reason you say.
A better approach would be to only include finished features in the production build - unfinished features that are still in testing should not be sent to the client. For such features, have a separate build. Host it:
On a local dev server (usually one running on the developer's personal machine) (great when one is making rapid changes), or
On a staging server - one that's accessible to all developers, and works similarly to the live site, but isn't the same as the production URL
A staging server is the professional approach when multiple devs need access to it at once. It can take some work at first to integrate it into your build process, but it's worth it for larger projects.

Related

Workflow for User Secrets in .netcore?

I'm playing around in .netcore and attempting to make use of the user secret store, some details are here: https://docs.asp.net/en/latest/security/app-secrets.html
I'm getting along with it well enough when working locally, but I'm having trouble understanding how this could be utilized effectively in a team environment, and if I wanted to work on this project from more than one computer.
The store itself (at least by default) keeps its configuration json file within the users/appdata (on windows). This feature is good to use if you're uploading the project to github, to hide your API keys, connection strings etc. This is all great when it's just me, on one machine working on a project. But how does this work when working in a team environment, or on multiple machines? The only thing I can think of is to find the configuration file, check it into a private repo, and make sure to replace it in the correct directory when changes occur.
Is there another way to manage this that I'm not aware of?
As you already know, the Secret Manager tool is providing another method to avoid checking sensitive data into source control by adding this layer of control.
So, where should we store sensitive configuration instead? The location should obviously be separate from your source code and, more importantly, secure. It could be in a separate private repository, protected fileshare, document management system, etc.
Rather than finding and sharing the exact configuration file, however, I would suggest keeping a script (e.g. .bat file) that you would run on each machine to set your secrets. For example:
dotnet user-secrets set MySecret1 ValueOfMySecret1 --project c:\work\WebApp1
dotnet user-secrets set MySecret2 ValueOfMySecret2 --project c:\work\WebApp1
This would be more portable between machines and avoid the hassle of knowing where to find and copy the config files themselves.
Also, for these settings, consider whether you need them to be the same across all developers in your team. For local development, I would normally want to have control to install, use, and name resources differently than others in my team. Of course, this depends on your situation and preferences, and I see reasons to share them too.

Adding centralized configuration to our servers

As our systems grow, there are more and more servers and services (different types and multiple instances of the same type that require minor config changes). We are looking for a "cetralized configuration" solution, preferably existing and nothing we need to develop from scrtach.
The idea is something like, service goes up, it knows a single piece of data (its type+location+version+serviceID or something like that) and contacts some central service that will give it its proper config (file, object or whatever).
If the service that goes online can't find the config service it will either use a cached config or refuse to initialize (behavior should probably be specified in the startup parameters it's getting from whom or whatever is bringing it online)
The config service should be highly avaiable i.e. a cluster of servers (ZooKeeper keeps sounding like a perfect candidate)
The service should preferably support the concept of inheritence, allowing a global configuration file for the type of service and then specific overrides or extensions for each instance of the service by its ID. Also, it should support something like config versioning, allowing to keep different configurations of the same service type for different versions since we want to rely more on more on side by side rollout of services.
The other side of the equation is that there is a config admin tool that connects to the same centralized config service, and can review and update all the configurations based on the requirements above.
I know that if I modify the core requirement from serivce pulling config data to having the data pushed to it I can use something like puppet or chef to manage everything. I have to be honest, I have little experience with these two systems (our IT team has more), but from my investigations I can say it seemed they are NOT the right tools for this job.
Are there any systems similar to the one I describe above that anyone has integrated with?
I've only had experience with home grown solutions so my answer may not solve your issue but may help someone else. We've utilized web servers and SVN robots quite successfully for configuration management. This solution would not mean that you would have to "develop from scratch" but is not a turn-key solution either.
We had multiple web-servers each refreshing its configurations from a SVN repository at a synchronized minute basis. The clients would make requests of the servers with the /type=...&location=...&version=... type of HTTP arguments. Those values could then be used in the views when necessary to customize the configurations. We did this both with Spring XML files that were being reloaded live and standard field=value property files.
Our system was pull only although we could trigger a pull via JMX If necessary.
Hope this helps somewhat.
Config4* (of which I am the maintainer) can provide you with most of the capabilities you are looking for out-of-the-box, and I suspect you could easily build the remaining capabilities on top of it.
Read Chapters 2 and 3 of the "Getting Started" manual to get a feel for Config4*'s capabilities (don't worry, they are very short chapters). Doing that should help you decide how well Config4* meets your needs.
You can find links to PDF and HTML versions of the manuals near the end of the main page of the Config4* website.

What does "headless" mean?

While reading the QTKit Application Programming Guide I came across the term 'headless environments' - what does this mean? Here is the passage:
...including applications with a GUI and tools intended to run in a “headless” environment. For example, you can use the framework to write command-line tools that manipulate QuickTime movie files.
"Headless" in this context simply means without a graphical display. (i.e.: Console based.)
Many servers are "headless" and are administered over SSH for example.
Headless means that the application is running without a graphical user interface (GUI) and sometimes without user interface at all.
There are similar terms for this, which are used in slightly different context and usage. Here are some examples.
Headless / Ghost / Phantom
This term is rather used for heavy weight clients. The idea is to run a client in a non-graphical mode, with a command line for example. The client will then run until its task is finished or will interact with the user through a prompt.
Eclipse for instance can be run in headless mode. This mode comes in handy when it comes to running jobs in background, or in a build factory.
For example, you can run Eclipse in graphic mode to install plugins. This is OK if you just do it for yourself. However, if you're packaging Eclipse to be used by the devs of a large company and want to keep up with all the updates, you probably want to find a more reproducible, automatic easier way.
That's when the headless mode comes in: you may run Eclipse in command line with parameters that indicate which plugins to install.
The nice thing about this method is that it can be integrated in a build factory!
Faceless
This term is rather used for larger scale application. It's been coined in by UX designers. A faceless app interacts with users in a manner that is traditionally dedicated to human users, like mails, SMS, phone... but NOT a GUI.
For example, some companies use SMS as an entry point to dialog with users: the user sends a SMS containing a request to a certain number. This triggers automated services to run and reply to the user.
It's a nice user experience, because one can do some errands from one's telephone. You don't necessarily need to have an internet connection, and the interaction with the app is asynchronous.
On the back-end side, the service can decide that it does not understand the user's request and get out of the automated mode. The user enters then in an interactive mode with a human operator without changing his communication tool.
You most likely know what a browser is. Now take away the GUI, and you have what’s called a headless browser. Headless browsers can do all of the same things that normal browsers do, but faster. They’re great for automating and testing web pages programmatically.
Headless can be referred in terms of a browser or a program that doesn't require a GUI. Not really useful for a general person to view and only to pass the info in the form of code to another program.
So why one uses a Headless program?
Simply because it improves the speed and performance and is available for all user, including those that have access to the graphic card. Allows testing browserless setups and helps you multitask.
Guide to Headless Browser
What is GUI ?
In software development it is an architectural design that completely separates the backend from the front end. The front end, gui, or UI is a stand alone piece and communicates to the backend through an API. This allows for a multi server architecture, flexibility in software stack and performance optimization.

What's the best way to notify a non-web application about a change on a web page?

Let's say I have two applications which have to work together to a certain extent.
A web application (PHP, Ruby on Rails, ...)
A desktop application (Java, C++, ...)
The desktop application has to be notified from the web application and the delay between sending and receiving the notification must be short. (< 10 seconds)
What are possible ways to do this? I can think of polling in a 10 second interval, but that would produce much traffic if many desktop applications have to be notified. On a LAN I'd use an UDP broadcast, but unfortunately that's not possible here...
I appreciate any ideas you could give me.
I think the "best practice" here will depend on the number of desktop clients you expect to serve. If there's just one desktop to be notified, then polling may well be a fine approach -- yes, polling is much more overhead than an event-based notification, but it'll certainly be the easiest solution to implement.
If the overhead of polling is truly unacceptable, then I see two basic alternatives:
Keep a persistent connection open between the desktop and web-server (could be a "comet"-style web request, or a raw socket connection)
Expose a service from within the desktop app, and register the address of the service with the web-server. This way, the web-server can call out to the desktop as needed.
Be warned, though -- both alternatives are chock full of gotchas. A few highlights:
Keeping a connection open can be tricky, since you want your web-servers to be hot-swappable
Calling out to an external service (eg, your desktop) from a web-server is dangerous, because this request could hang. You'd want move this notification onto a separate thread to avoid tying up the webserver.
To mitigate some of the concerns, you might decouple the unreliable desktop from the web-server by introducing an intermediary notification server -- the web-server could post an update somewhere, and the desktop could poll/connect/register there to be notified. To avoid reinventing the wheel here, this could involve some sort of MessageQueue system... This, of course, adds the complexity of needing to maintain the new intermediary.
Again, all of these approaches are probably quite complex, so I'd say polling is probably the best bet.
I can see two ways:
Your desktop application polls the web app
Your web app notifies the desktop application
Your web app could publish an RSS feed, but your desktop app will still have to poll the feed every 10 s.
The traffic need not be huge: if you use an HTTP HEAD request, you'll get a small packet with the date of the last modification (conveniently named Last-Modified).
I don't know exactly what to do to achieve your task but I can suggest to create a windows service at the desktop application PC.
This service checks the web application every interval of time for new changes and if changes occurred it can run the desktop application with notification that there is a change in the web application and in the web application when any change occurrs you can response with acknowledgment
I hope that this may be useful I didn't try it exactly but I am suggesting using like this idea.
A layer of syndication would help to scale out the system.
The desktop app can register itself with a "publisher" service (running on one of several/many machines) This publisher service receives the "notice" from your web app that something has changed, and immediately starts notifying all of its registered subscribers.
The number of publishers you need will increase with the number of users.
Edit: Forgot to mention that the desktop app will need to listen on a socket.

Where can I start about designing a website

I want to design a website but I don't know from where to start.
Is there a beginners' guide to start with?
How much dedication do you hope to provide? If you merely want to design a single website, quickly and dirty, there's a plethora of open source web templates available online, with clean and basic HTML/XHTML design strategies that you could modify, and provide content for.
Such as this and that.
Alternatively, if you would like to design your own websites from scratch and have full technical knowledge in the field (the proper way). Pick up a book or two on HTML/XHTML/XML, with documentation on content management systems, php, etc.
You'd soon find that in the beginning your development would be gradual and at best, slow. If you put in sufficient effort, you would find that you get to the point where you can quickly design sites confidently, which best illuminate your content.
You should be familiar with this and this
Try this Web Design from Scratch
I understand by website you mean some kind of web-app. And by design you mean, not just the page design but the design of the web-app. First, you have to understand the anatomy of a web-app. The major components are:
Database is used to store user and application data for long term. A database provides query functionality (SQL), backup on one installation and restore on another, triggers when a data entry changes, and constraints that must be satisfied by the data tables.
Web Server, also called Http Server hosts the web application.
Web Browser such as Internet Explorer or Firefox.
When a user types a URL into the web browser, the web server forwards the URL to the corresponding web application. The web application performs the needed tasks (which may involve reading or writing into the database) and returns a new html page to the user via www.
Some components of the web application are:
Database access objects are representations of objects that encapsulate interaction with database tables.
Business Logic is the main logic of the application. Here we implement the search functionality using Lucene library, for example.
Action Handler handles a http request received from the user, for example when she types a URL or when she clicks on the "submit" button. These are Http GET and POST requests. The Action Handler uses the business logic to drive the actions.
Data view on the web brower is constructed using some template library (which usually produces javascript user interface code for the web browser). For interactivity one may use Ajax techniques.
Almost all web-apps separate the model, view and controller of a web application. The view deals with the display, the model deals with data and the controller deals with control/functioning. See http://www.uidesign.net/Articles/Papers/UsingMVCPatterninWebInter.html.
Several frameworks implement MVC. The most easy ones to get started are Ruby on Rails and Django (over which an open source social network called Pinax too is written). There are much more comprehensive frameworks and libraries in java too (for a single web appl you may need to join several of these libraries), such as spring, webwork, tapestry, lucene (for search), sitemesh (for page decoration). Many java web apps run on tomcat web server and with mysql database.
I started with http://w3schools.com. Make sure you're using Firefox and the Firebug addon. Get your hands dirty then get familiar with the web design community.
I have CSS Mastery by Andy Budd on my desk and it's a good, readable, short, yet deep guide to CSS.
Don't Make me think has also become my mantra of web design.
Overall, you're going to produce a lot of crap--as I have--before you get good. If you have someone to look over what you're doing that'll be the best help. Personal drive will matter the most in the long run though, so stick with it and keep learning.
Liz Castro has a good book too.