I'm new to git. I've read the well-written intro book. But gee, it's still not a trivial topic. I've been bumbling around, experiencing various problems. I realized it might be because I'm unaware of workflow, and specifically, "what are the best practices for doing what I'm trying to do?"
I started out developing a django project on my win7 with Pycharm. Great way to get the initial 95% written.
But then I need to deploy it to my production machine at PythonAnywhere.
So I created a private Github repository, pushed my win7 codebase to github.
Then in pythonAnywhere, I cloned the github repository.
For now, no others work on this project. It will not be released to the public.
Now that the server is running on PythonAnywhere, I still need to tweak settings, which is best done on the PythonAnywhere codebase side. But there are other improvements (new pages, or views) that I'd rather do inside Pycharm IDE on my win7 than in vim on python anywhere.
So I've been kind of clumsily pushing and fetching these changes. It's been kind of ham-handed, and I've managed to lose some minor changes through ignorance.
So I'm wondering if anyone can point to a relatively simple workflow that would handle the various tasks I mentioned:
1) improving functionality of the site (best done in Pycharm IDE)
2) production server issues and tweaks (best done on PythonAnywhere)
3) keeping everythign safely backed-up on Github
The other issue is that I have another django app that I want to build. It's easiest to temporarily hang it off the django project I've already built. But I'd prefer to keep it in its own repository.
So I have Original_Project, Original_App stored in Original_Repository
I want to make new_app, and have it, for the time being, run in Original_Project, but I want to version control it in New_Repository.
I think/hope that I could put a .gitignore in the Original_Repository, saying ignore the new_app/ Then I git init new_app/ as its own repository. Is that sound or mad?
You should avoid editing your code on the production server as much as possible, and never commit from the production server. If you end up having to tweaks things on the server (you shouldn't but well, shit happens and sometimes it's indeed easier to first get the code back to work on the server), then once it's working manually report your edits to your local repo, clear up the changes on the server and deploy the fixed code again. Here the github repo should be considered as the "master" repository for deployments, ie you work on your local repo, push to github, and on the server pull from github. This make sure you keep the github repo in sync.
wrt/ the "improving functionality" (aka "features") vs "server issues and tweaks" (aka "hotfixes"), git flow is a (mostly) sane workflow IMHO but that's a bit opinion-based here (some dislike it and have sensible arguments too).
Finally if you want to factor out one of your apps, the best is to have it in it's own (github) repo with all the proper python packaging stuff and make it a requirement of your main project. On your local dev environment you install it as an editable package, and for the production setup you install it as normal package pinned to the last stable version. Note that in both cases I assume you're using virtualenvs (and if you dont, well that's the very first issue you should address).
Update:
What are the downsides of of editing directly on the production server and committing from the production server?
Well quite simply a production server is not the place for coding - "production" means that you have users trying to do something with your website and they don't want to have the site breaking on them, their data lost or whatever because you are "tweaking" things. You should only deploy stable, well tested code on production, and the one and only one case where editing anything on the server might be a last resort option is when it's already broken and you want to get it back online asap whatever it takes (case of "first make it work, then make it clean").
Point is, I'm a professional developer working on projects that are business criticals and a broken site is not an option, so I'm very strict on this - but even if it's a hobby project, your users deserve some respect (at least if you expect to see them back).
A proper production chain actually involves at least three environments: your local dev environment, a staging server (which should closely mirror the production server - system, system package versions, configurations etc etc) to test out / showcase / eventually do minor config tweak, and the production server which should only ever see stable tested code.
I have always struggled with git, knowing it well enough to get thigs working, but never being sure I am doing thing well.
I would suggest installing git flow (it is probably available in your package manager if you are on Linux). Its a set of extensions that simplify a standard git worklfow. Since using it, this has pretty much been all the documentation I have needed.
https://danielkummer.github.io/git-flow-cheatsheet/
Related
I built a (relatively simple) Django project following a tutorial (the recently released Hello Web App book.) I committed my changes along each step of the way, and I have my working solution in a github repo. However, when I clone the code into a new work space such as onto a new machine or into a new slot on a cloud IDE, the app doesn't work. I get a few errors and with each I resolve, another pops up. Basically, my environment is totally messed up and incompatible with the app beyond having Python and Django both installed.
I realize that I can read through the error messages I get when I invoke runserver, solve each one by one, etc. but it seems there should be a cleaner/simpler way to be able to pull down my repo to a fresh workspace and have it up and running in just a minute or two. I've read recommendations about using virtualenv, but it also seems like people discourage including venv inside your repo because of the extraneous commits and added bulk that will result from it so I don't think that actually solves my problem of trying to reduce new workspace configuration effort.
Perhaps I am overly optimistic, but I'm hoping someone can give me a recommendation to avoid the need to workout these kinks each time I start fresh.
I am working with a client that demands multi-stage server setup: development server, stage server and production/live server.
Stage should be as stable as it can be to test all those new features we develop at the development server and take this to the live server in the end.
We use git and github for version controlling. I use Ubuntu server edition as the OS.
The problem is, I have never working in such multi-stage server plan. What software/projects would you recommend to do a proper way of handling such setup, especially deployment and moving a new feature developed to the stage and then to the live server ?
We use two different methods of moving code from environment to environment. The first is to use branches and triggers with our source control system (mercurial in our case, though you can do the same thing with git). The other, is to use fabric, a python library for executing shell code across a number of servers.
Using source control, you can have several main branches, like production development staging. Say you want to move a new feature into staging. I'll explain in terms of mercurial, but you can port the commands over to git and it should be fine.
hg update staging
hg merge my-new-feature
hg commit -m 'my-new-feature > staging'
hg push
You then have your remote source control server push to all of your web servers using a trigger. A trigger on each web server will then do an update and reload the web server.
To move from staging to production, it's just as easy.
hg update production
hg merge staging
hg commit -m 'staging > production'
hg push
It's not the nicest method of deployment, and it makes rolling back quite hard. But it's quick and easy to set up, and still a lot better than manually deploying each change to each server.
I won't go through fabric, as it can get quite involved. You should read their documentation so you understand what it is capable of. There are plenty of tutorials around for fabric and django. I highly recommend the fabric route as it gives you lots more control, and only involves writing some python.
There is a nice branching model for git (as it is also used by github itself for example). You can easily apply this branching model using git-flow, which is a git extension that enables you to apply some high level repository operations that fit into this model. There's also a nice blogpost about this.
I do not know what exactly you want to automize in your deployment workflow, but if you apply the model mentioned above, most of the correct version handling is done by git.
To add some further automatic processing to this, fabric is a simple but great tool, and you will find many tutorials about its usage (also in combination with git).
For handling python dependencies using virtualenv and pip is for sure a very good way to go.
If you need something more complex,eg. to handle more than one django instance on one machine and for handling system wide dependencies etc checkout puppet or chef.
Try Gondor.io or Ep.io, they both make it pretty easy (gondor especially excels in this area) to have two+ instances with very similar code, from your VCS -- and to move data back and forth. (if you need an invite, ask either in IRC, but if I recall, they're both open now)
I am trying to work out a good way to run a staging server and a production server for hosting multiple Coldfusion sites. Each site is essentially a fork of a repo, with site specific changes made to each. I am looking for a good way to have this staging server move code (upon QA approval) to the production server.
One fanciful idea involved compiling the sites each into EAR files to be run on the production server, but I cannot seem to wrap my head around Coldfusion archives, plus I cannot see any good way of automating this, especially the deployment part.
What I have done successfully before is use subversion as a go between for a site, where once a site is QA'd the code is committed and then the production server's working directory would have an SVN update run, which would then trigger a code copy from the working directory to the actual live code. This worked fine, but has many moving parts, and still required some form of server access to each server to run the commits and updates. Plus this worked for an individual site, I think it may be a nightmare to setup and maintain this architecture for multiple sites.
Ideally I would want a group of developers to have FTP access with the ability to log into some control panel to mark a site for QA, and then have a QA person check the site and mark it as stable/production worthy, and then have someone see that a site is pending and click a button to deploy the updated site. (Any of those roles could be filled by the same person mind you)
Sorry if that last part wasn't so much the question, just a framework to understand my current thought process.
Agree with #Nathan Strutz that Ant is a good tool for this purpose. Some more thoughts.
You want a repeatable build process that minimizes opportunities for deltas. With that in mind:
SVN export a build.
Tag the build in SVN.
Turn that export into a .zip, something with an installer, etc... idea being one unit to validate with a set of repeatable deployment steps.
Send the build to QA.
If QA approves deploy that build into production
Move whole code bases over as a build, rather than just changed files. This way you know what's put into place in production is the same thing that was validated. Refactor code so that configuration data is not overwritten by a new build.
As for actual production deployment, I have not come across a tool to solve the multiple servers, different code bases challenge. So I think you're best served rolling your own.
As an aside, in your situation I would think through an approach that allows for a standardized codebase, with a mechanism (i.e. an API) that allows for the customization you're describing. Otherwise managing each site as a "custom" project is very painful.
Update
Learning Ant: Ant in Action [book].
On Source Control: for the situation you describe, I would maintain a core code base and overlays per site. Export core, then site specific over it. This ensures any core updates that site specific changes don't override make it in.
Call this combination a "build". Do builds with Ant. Maintain an Ant script - or perhaps more flexibly an ant configuration file - per core & site combination. Track version number of core and site as part of a given build.
If your software is stuffed inside an installer (Nullsoft Install Shield for instance) that should be part of the build. Otherwise you should generate a .zip file (.ear is a possibility as well, but haven't seen anyone actually do this with CF). Point being one file that encompasses the whole build.
This build file is what QA should validate. So validation includes deployment, configuration and functionality testing. See my answer for deployment on how this can flow.
Deployment:
If you want to automate deployment QA should be involved as well to validate it. Meaning QA would deploy / install builds using the same process on their servers before doing a staing to production deployment.
To do this I would create something that tracks what server receives what build file and whatever credentials and connection information is necessary to make that happen. Most likely via FTP. Once transferred, the tool would then extract the build file / run the installer. This last piece is an area I would have to research as to how it's possible to let one server run commands such as extraction or installation remotely.
You should look into Ant as a migration tool. It allows you to package your build process with a simple XML file that you can run from the command line or from within Eclipse. Creating an automated build process is great because it documents the process as well as executes it the same way, every time.
Ant can handle zipping and unzipping, copying around, making backups if needed, working with your subversion repository, transferring via FTP, compressing javascript and even calling a web address if you need to do something like flush the application memory or server cache once it's installed. You may be surprised with the things you can do with Ant.
To get started, I would recommend the Ant manual as your main resource, but look into existing Ant builds as a good starting point to get you going. I have one on RIAForge for example that does some interesting stuff and calls a groovy script to do some more processing on my files during the build. If you search riaforge for build.xml files, you will come up with a great variety of them, many of which are directly for ColdFusion projects.
I just finished a Django app that I want to get some outside user feedback on. I'd like to launch one version and then fork a private version so I can incorporate feedback and add more features. I'm planning to do lots of small iterations of this process. I'm new to web development; how do websites typically do this? Is it simply a matter of copying my Django project folder to another directory, launching the server there, and continuing my dev work in the original directory? Or would I want to use a version control system instead? My intuition is that it's the latter, but if so, it seems like a huge topic with many uses (e.g. collaboration, which doesn't apply here) and I don't really know where to start.
1) Seperate URLs www.yoursite.com vs test.yoursite.com. you can also do www.yoursite.com and www.yoursite.com/development, etc.. You could also create a /beta or /staging..
2) Keep seperate databases, one for production, and one for development. Write a script that will copy your live database into a dev database. Keep one database for each type of site you create. (You may want to create a beta or staging database for your tester).. Do your own work in the dev database. If you change the database structure, save the changes as a .sql file that can be loaded and run on the live site database when you turn those changes live.
3) Merge features into your different sites with version control. I am currently playing with a subversion setup for web apps that has my stable (trunk), one for staging, and one for development. Development tags + branches get merged into staging, and then staging tags/branches get merged into stable. Version control will let you manage your source code in any way you want. You will have to find a methodology that works for you and use it.
4) Consider build automation. It will publish your site for you automatically. Take a look at http://ant.apache.org/. It can drive a lot of automatically checking out your code and uploading it to each specific site as you might need.
5) Toy of the month: There is a utility called cUrl that you may find valuable. It does a lot from the command line. This might be okay for you to do in case you don't want to use all or any of Ant.
Good luck!
You would typically use version control, and have two domains: your-site.com and test.your-site.com. Then your-site.com would always update to trunk which is the current latest, shipping version. You would do your development in a branch of trunk and test.your-site.com would update to that. Then you periodically merge changes from your development branch to trunk.
Jas Panesar has the best answer if you are asking this from a development standpoint, certainly. That is, if you're just asking how to easily keep your new developments separate from the site that is already running. However, if your question was actually asking how to run both versions simultaniously, then here's my two cents.
Your setup has a lot to do with this, but I always recommend running process-based web servers in the first place. That is, not to use threaded servers (less relevant to this question) and not embedding in the web server (that is, not using mod_python, which is the relevant part here). So, you have one or more processes getting HTTP requests from your web server (Apache, Nginx, Lighttpd, etc.). Now, when you want to try something out live, without affecting your normal running site, you can bring up a process serving requests that never gets the regular requests proxied to it like the others do. That is, normal users don't see it.
You can setup a subdomain that points to this one, and you can install middleware that redirects "special" user to the beta version. This allows you to unroll new features to some users, but not others.
Now, the biggest issues come with database changes. Schema migration is a big deal and something most of us never pay attention to. I think that running side-by-side is great, because it forces you to do schema migrations correctly. That is, you can't just shut everything down and run lengthy schema changes before bringing it back up. You'd never see any remotely important site doing that.
The key is those small steps. You need to always have two versions of your code able to access the same database, so changes you make for the new code need to not break the old code. This breaks down into a few steps you can always make:
You can add a column with a default value, or that is optional. The new code can use it, and the old code can ignore it.
You can update the live version with code that knows to use a new column, at which point you can make it required.
You can make the new version ignore a column, and when it becomes the main version, you can delete that column.
You can make these small steps to migrate between any schemas. You can iteratively add a new column that replaces an old one, roll out the new code, and remove the old column, all without interrupting service.
That said, its your first web app? You can probably break it. You probably have few users :-) But, it is fantastic you're even asking this question. Many "professionals" fair to ever ask it, and even then fewer answer it.
What I do is have an export a copy of my SVN repository and put the files on the live production server, and then keep a virtual machine with a development working copy, and submit the changes to the repo when Im done.
Joel seems to think highly of daily builds. For a traditional compiled application I can certainly see his justification, but how does this parallel over to web development -- or does it not?
A bit about the project I'm asking for --
There are 2 developers working on a Django (Python) web app. We have 1 svn repository. Each developer maintains a checkout and thier own copy of MySQL running locally (if you're unfamiliar with Django, it comes bundled with it's own test server, much the way ASP apps can run inside of Visual Studio). Development and testing are done locally, then committed back to the repository. The actual working copy of the website is an SVN checkout (I know about SVN export and it takes too long). The closest we have to a 'build' is a batch file that runs an SVN update on the working copy, does the django bits ('manage.py syncdb'), updates the search engine cache (solr), then restarts apache.
I guess what I don't see is the parallel to web apps.
Are you doing a source controlled web app with 'nightly builds' -- if so, what does that look like?
You can easily run all of your Django unit tests through the Django testing framework as your nightly build.
That's what we do.
We also have some ordinary unit tests that don't leverage Django features, and we run those, also.
Even though Python (and Django) don't require the kind of nightly compile/link/unit test that compiled languages do, you still benefit from the daily discipline of "Don't Break The Build". And a daily cycle of unit testing everything you own is a good thing.
We're in the throes of looking at Python 2.6 (which works perfectly for us) and running our unit tests with the -3 option to see which deprecated features we're using. Having a full suite of unit tests assures us that a change for Python 3 compatibility won't break the build. And running them nightly means that we have to be sure we're refactoring correctly.
Continuous integration is useful if you have the right processes around it. TeamCity from JetBrains is a great starting point if you want to build familiarity:
http://www.jetbrains.com/teamcity/index.html
There's a great article that relates directly to Django here:
http://www.ajaxline.com/continuous-integration-in-django-project
Hope this gets you started.
Web applications built in dynamic languages may not require a "compilation" step, but there can still be a number of "build" steps involved in getting the app to run. Your build scripts might install or upgrade dependencies, perform database migrations, and then run the test suite to insure that the code is "clean" w.r.t. the actual checked-in version in the repository. Or, you might deploy a copy of the code to a test server, then run a set of Selenium integration tests against the new version to insure that core site functionality still works.
It may help to do some reading on the topic of Continuous Integration, which is a very useful practice for webapp dev teams. The more fast-paced and agile your development process, the more you need regular input from automated testing and quality metrics to make sure you fail fast and loud on any broken version of the code.
If it's really just you and one other developer working on it, nightly builds are probably not going to give you much.
I would say that the web app equivalent of nightly builds would be staging sites (which can be built nightly).
Where nightly builds to a staging area start paying real dividends is when you have clients, project managers, and QA people that need to be able to see an up to date, but relatively stable version of the app. Your developer sandboxes (if you're like me, at least) probably spend a lot of time in an unusable state as you're breaking things trying to get the next feature implemented. So the typical problem is that a QA person wants to verify that a bug is fixed, or a PM wants to check that some planned feature was implemented correctly, or a client wants to see that you've made progress on the issue that they care about. If they only have access to developer sandboxes, there's a good chance that when they get around to looking at it, either the sandbox version isn't running (since it means ./manage.py runserver is up in a terminal somewhere) or it's in a broken state because of something else. That really slows down the whole team and wastes a lot of time.
It sounds like you don't have a staging setup since you just automatically update the production version. That could be fine if you're way more careful and disciplined than I (and I think most developers) am and never commit anything that isn't totally bulletproof. Personally, I'd rather make sure that my work has made it through at least some cursory QA by someone other than me before it hits production.
So, in conclusion, the setup where I work:
each developer runs their own sandbox locally (same as you do it)
there's a "common" staging sandbox on a dev server that gets updated nightly from a cronjob. PMs, clients, and QA go there. They are never given direct access to developer sandboxes.
There's an automated (though manually initiated) deployment to production. A developer or the PM can "push" to production when we feel things have been sufficiently QA'd and are stable and safe.
I'd say the only downside (besides a bit of extra overhead setting up the nightly staging builds) is that it makes for a day of turnaround on bug verification. ie, QA reports a bug in the software (based on looking at that day's nightly build), developer fixes bug and commits, then QA must wait until the next day's build to check that the bug is actually fixed. It's usually not that much of a problem since everyone has enough stuff going on that it doesn't affect the schedule. When a milestone is approaching though and we're in a feature-frozen, bugfix only mode, we'll do more frequent manual updates of the staging site.
I've had great success using Hudson for continuous integration. Details on using Hudson with Python by Redsolo.
A few months ago, several articles espousing continuous deployment caused quite a stir online. IMVU has details on how they deploy up to 5 times a day.
The whole idea behind frequent builds (nightly or more frequent like in continuous integration) is to get immediate feedback in order to reduce the elapsed time between the introduction of a problem and its detection. So, building frequently is useful only if you are able to generate some feedback through compilation, (ideally automated) testing, quality checks, etc. Without feedback, there is no real point.