Hello heroku

Heroku is a web app hosting platform introduced by the SaaS course I take. It's a lot like GAE, but somehow different. For now all I know is it works like a git remote, every time you update/deploy your web app you just push it to heroku remote. One of its biggest feature is scalability: you could start with free account, 5mb/app for storage, no dyno (a work unit in its world), and then choose whatever combination you like to scale up during the development.

I absolutely start with free account. Heroku has a very thorough setup post about django app. But before django I come across this blog about python development environment. It suggests to use virtual environment for every python project I do, because different project might require different version of one package. Make sense. Therefore I use this virtualenv package, followed the excellent-written blog to build up a virtual development for my django project. Virualenv is very easy to use, it comes with pip: every time you setup a completely clean environment, then add packages you want for this particular project using pip.

Done configuring the virtual environment, I start doing this heroku app. Detailed steps are in the tutorial post of heroku. During the setup I meet this problem with ssh keys. It killed me. I have an ssh key previously for github, I didn't realize that its owner has been changed into root. Then when I tried to do git push using this key I keep getting error saying Permission denied (without sudo, for ssh normally you don't need sudo). It took me a while to figure out the root problem from the fact that I could not regenerate the key. Anyway, finally I chown the key also ~/.ssh folder back to my control and regenerate the key.

After that I got a strange problem saying:

-----> Heroku receiving push
 !     Heroku push rejected, no Cedar-supported app detected

I find I misplaced my git into a subdir of my django project. Also, the requirements.txt generated by the virtualenv should be in the git dir. Now everything is done. My first Heroku app.

In the heroku tutorial I find this link to a collection of .gitignore files on github, which is used to ignore useless/auto-generate files of your project during git commit. It provides ignore files fore different languages, very handy.

Heroku use this push strategy, making me feel like coding at home, because I own the environment. Now I could install whatever python packages I like and then push them all up. Beside it has a series of very detailed tutorials on how to get started with different app frameworks also how to use heroku toolset. I think hosting on heroku is not a bad idea. Tomorrow I will try to get back my site on it.