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A Proper Environment for Web Development?
umdenken wonders: "I'd like to know how others on Slashdot do their server-side web programming. We have dozens of Perl CGI scripts, and are currently doing development by editing these production scripts in place on the web server (!). Our sysadmins have finally installed an SVN client on the server (Solaris), and have offered to create a new virtual host that we can use as the development server. What are some of the practices you use for organizing this kind of set up?"
Even with a virtual host, you'll still be hitting the production hardware. Sounds like an ideal use for virtualisation here - mimic as much of the production environment as possible (OS versions, web server versions, application container versions etc.) and have a go with that.
Subversion is definitely a stride forward - well worth using and getting used to, it's good that you have a client there. You should be able to fix your config scripts such they they recognise the environment (prod, dev, uat) and can be deployed directly from a tag in svn. A tag of course, not the trunk. Given the constraints it sounds like you're up against, I would definitely be looking to virtualise at least three environments - one dev, one system test, one UAT. You may have multiple dev virtual machines depending on your needs.
Cheers,
Ian
In my experience, I have found that it is best to have four environments: Production, Pre-Production, Testing, and Development. Every environment is isolated and has the same hardware and software.
Developers do their development in one environment (if possible, each developer should be isolated), and when their code is written it goes to a testing server where it can be hammered by your QA/Testing team.
When it passes QA, it goes into Pre-Production, which is what your Production environment should look like when you push your changes live. Any kind of external integration can test against this environment, since it is as close to your production environment as possible.
Then, you have your production environment where everything is live.
It is VITAL that each environment is set up the exact same way, or as close as possible, to every other environment. Each one should have its own separate hardware running identical software versions - unless you are testing software upgrades, in which case you FREEZE THE CODE, update Development, then QA, the Pre-Production, then Production (testing everything, everywhere), and THEN resume writing your code again. It is incredibly frustrating for a developer when code works on servers A, B, and D, but breaks on C and E due to non-matching hardware and software.
It is also important that your developers and qa team have access to fresh, live data if at all possible. It is easier to develop when you have real data to develop with; Plan on updating your QA and development data once a week.
If you have a set up like this, then development, testing, and deployment will be very smooth. It can be a bit of a pain to set up at first, especially if you are not used to the idea, but once you have something like this I promise that you will never go back.
Other people may recommend different set ups, but the basic idea is the same. Keep the developers separate from the testers, keep everyone separate from production. The pre-production just makes deployment easier - push code that passes QA to pre-production, then when the time comes, just rsync the files over.
Love sees no species.
In my opinion, there is a point at which complexity outstrips any gains from separation. Just keep it simple; dev, staging, production.
~ I am logged on, therefore I am.
I'll tell you how our entire setup works, and hope it helps:
...
A. Development Box
B. Test Server
C. Production Server
A. Development Box
Every developer has Apache (or IIS respectively) and PHP/SQL on his box. People without experience can just install one of the premade packages that exist (like XAMPP or whatever its name was). This setup is isolated from the outside and responds only to 127.0.0.1 and the virtual domains. Each virtual host in Apache is a separate project.
Server Side Developers work in Eclipse PHP IDE with SubClipse, designers/client side work in Dreamweaver/Photoshop with SVN4DW & TortoiseSVN.
B. Test Server
This is used for few purposes: devs can checkout a revision and run it there on a "real" server to test, QA (well we have no dedicated QA.. it's a small team) can test on this server too.
If everything is ok it goes to...:
C. Production Server
That's it, it works really well though, everyone has his own server that can run files right of his PC, and this helps a lot in quick development. Showing to clients is as easy as checking out a revision on the test server.
This is Unix/OSX-centric, and I've been doing this for years and showing others the way:
.....
.. by the way, use daemontools to supervise your daemons, anything else like crappy pidfile-based startup scripts are unpredictable). Ideally someone OTHER THAN YOURSELF should be able to mindlessly follow some simple instructions to accomplish this step. Design your procedures with this in mind.
.. OR when you get a SECOND client who will run an older version of t
* My code always has a standard layout (bin, conf, src, lib, and so on). No exceptions, because you never know when that little script will become a big app (this happens to me at least once a year).
* Use good coding practices: unit tests, continuous integration, whatever
* The code is checked into CVS/Subversion/Darcs, whatever. Use branches and so forth intelligently (dev on the trunk, release branches which are bugfix only, whatever). Make it "obvious" where the latest stable code always lives, so that someone besides yourself can deploy it.
* I have a script which will deploy the app to any server with rsync (excluding CVS, config, test, and dev files). There is also a flag that will "pull" the files from the server, in case of an emergency fix that was done directly on the server.
* There's a "config" directory with all system-dependent configs. No passwords or other stuff is hard-wired into the app.
* As others have described, you have your various "dev" machines, a "staging" server (identical to production but non-critical), and a "production" server. NEVER WORK ON THE PRODUCTION SERVER EXCEPT IN EMERGENCIES. Also, resist the temptation to install extra stuff on the staging server like some do (MRTG or Nagios or whatever). The staging server must be identical to the production in all respects.
If you do this properly, all you have to do to work is the following:
1) go to your laptop or other dev environment and check out the code.
2) review the REQUIREMENTS file for any packages you might need to install
3) adjust the app config files appropriately
3) code, test, checkin, code, test, checkin,
Then when you're ready to update the code on the server, first sync to the staging server and test as needed (user tests, whatever). Virtual hosts can work this way too (I've done it this way, for instance "foo.com" is the app and "dev.foo.com" is the staging version, on the same machine).
Once everything is working, push to the production servers (my script will also restart anything that's needed
I also agree with the poster above who said it's good to have different OS or environments on your dev machines, to catch any hidden assumptions. I dev on Linux and OSX and push to FreeBSD usually. Use conditional code as appropriate, and sparingly.
Ideally, you can take a blank server, install the OS, install the REQUIREMENTs, push the app, config the app, run a setup script, and go. No undocumented requirements. No weird "procedures". Just "push button install".
You should also get into the habit of making apps "learn" as much about their environment as possible. For instance, in my Ruby, Perl, PHP code, I use the __FILE__ variable or equivalent to determine the install dir, that way I don't have to configure it. A common library sets up all the necessary paths based on that.
Write your code to be flexible and backwards-compatible. For instance, if you need to move some data files around or change database fields, write code that detects the old version and does the update at startup time. A little extra work, but oh-so-automatic.
Once you get this working, you'll never want to work any other way. Being able to check out and deploy your code ANYWHERE in just a few steps is a very powerful feeling. Heck, just being able to check out in a different directory on your dev machine is useful. Having separate release branches are awesome when the client reports a bug but you've already started the big changes for 2.0