Author: rafalkowalski

This author has written 17 articles
Read more about the article How do we work? Agile

How do we work? Agile

It’s not typical team. We don’t meet face-to-face each other on daily basis, one trouble is that we have to work from different time zones, and we have different operating system, the way of working, or even culture. But we are FOSSASIA Open Event team of six amazing developers so it does not discourage us to achieve our goals.

But even if we experience all these things we have to learn how to work together successfully. We are trying, and I think it is becoming better and better every day, the Agile methodology.

So first of all, before coding started, we had prepared user stories in issues. Every issue had been very well documented, and we had divided each issue to smaller ones. It brings us a lot of benefits, because it doesn’t matter where you work. If sub issue is empty you can take it. Due to the fact that issue is very well documented you don’t need to even ask someone what to do. This case saves a lot of time. I know that writing clear issues is very boring and It could seemed not to be beneficial, but it’s. We are still trying to improve our performance and we are looking for new opportunities where and how we can improve our work, without lost quality of our development process.

Then, we have one week sprint (milestones). It helps us to control our work and we know where are we, what have we done, and what is still to do. We know if our speed is enough or we have to move faster. And it also enables us to see our progress.Screen Shot 2016-06-25 at 11.27.08.png

Moreover, we have daily scrums. We answer three following questions – what did you do yesterday, what do you plan to do today and what is preventing you from achieving your goals. Furthermore, we follow continues integration system. We push code to our common Open Event repository on daily basis. It helps us to control our code and fix bugs quickly. I am sure we will continue along this path, and successfully finish to code an amazing Open Event web app.

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Migrations make us crazy!

Our Open Event team is not small, so problems with migrations occur very often. I’d like to describe how to solve these common problems and avoid Contributors frustration. Because more of us didn’t know how to solve this problems at the beginning so we wasted a lot of time to find a source of problem.

The most common mistake is that we forget run migration on Heroku. Developer is sometimes surprised because something works for him but he forgets to run migration on server. These small mistakes lead to huge problems and at that time our app throws a lots of bugs related to database. We can often see “Internal server error”.Screen Shot 2016-06-17 at 22.55.25.png So if developer changes table he has to run migration!

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ python manage.py db migrate

But above command Quite often doesn’t solve our problem, because We face other problems while updating DB for example

alembic.util.exc.CommandError: Multiple head revisions are present for given argument ‘head’; please specify a specific target revision, ‘<branchname>@head’ to narrow to a specific head, or ‘heads’ for all heads

this problem is caused by two developers which push code to Github with migrations without merging two heads to achieve one head.

So to solve this problem you only have to know ids of two heads

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ python manage.py db heads

e38935822969 (head)
f55fde3d62b1 (head)

Then you have to merge it

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ python manage.py db merge e38935822969 f55fde3d62b1

Generating /vagrant/migrations/versions/ecb671d1eb4b_.py … done

Upgrade DB

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ python manage.py db upgrade

INFO [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO [alembic.runtime.migration] Will assume transactional DDL.
INFO [alembic.runtime.migration] Running upgrade 00ea66754d06 -> d84f976530e1, empty message
INFO [alembic.runtime.migration] Running upgrade d84f976530e1 -> 1b3e4f5f56bd, empty message
INFO [alembic.runtime.migration] Running upgrade 1b3e4f5f56bd -> e38935822969, empty message
INFO [alembic.runtime.migration] Running upgrade e38935822969, f55fde3d62b1 -> ecb671d1eb4b, empty message

And finally run migrations

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ python manage.py db migrate
INFO [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO [alembic.runtime.migration] Will assume transactional DDL.
INFO [alembic.ddl.postgresql] Detected sequence named ‘role_id_seq’ as owned by integer column ‘role(id)’, assuming SERIAL and omitting
INFO [alembic.ddl.postgresql] Detected sequence named ‘microlocation_id_seq’ as owned by integer column ‘microlocation(id)’, assuming SERIAL and omitting….

Continue ReadingMigrations make us crazy!

Why should you use Heroku?

Last week I’ve dedicated most time to implement new heroku features to Open Event. Due to the fact that wasn’t easy tasks I can share my experience.

What is heroku?

Heroku is a cloud Platform-as-a-Service (PaaS) supporting several programming languages like Java, Node.js, Scala, Clojure, Python, PHP, and Go

Easy to deploy

what you need to do:

  1. Create account on heroku
  2. Download a heroku toolbelt to your enviroment.
  3. Go to your project directory(/open-event-orga-server)
  4. Sign in to heroku in your command line using your credentials 
    $ heroku login
  5. Create app with name $ 
    heroku apps:create your_app_name

    after execution above command you will recive a link to your application

    http://your_app_name.herokuapp.com/
  6. Push latest changes to heroku 
    $ git push heroku master
  7. If everythings is ok you can check results http://your_app_name.herokuapp.com/ (sometimes it does not work like we want 🙁 )

Easy to configure

To list/set/get config variables use:

$ heroku config
$ heroku config:set YOUR_VARIABLE=token123

$ heroku config:get YOUR_VARIABLE

or you can go to you application dashboard and make above operations

How you can get access to this variables using python langauges?

$ python

Python 2.7.10 (default, Oct 23 2015, 19:19:21) 

[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin

Type "help", "copyright", "credits" or "license" for more information.

>>> import os

>>> your_variable  = os.environ.get('YOUR_VARIABLE', None)


>>> print your_variable
token123

I’ve used this to display current release in my python application(You need to generate a special API token and add it to config variables)

os.popen('curl -n https://api.heroku.com/apps/open-event/releases -H 
"Authorization: Bearer ' + token + '" -H 
"Accept: application/vnd.heroku+json; version=3"').read()

Easy to monitor

If something is wrong with your APP you need to use this command

$ heroku logs

it shows all logs

To see 10 latest releases use:

$ heroku releases

How you can set up Open Event to deploy to heroku?

  1. Clone https://github.com/fossasia/open-event-orga-server
  2. Go to directory of open event orga server(/open-event-orga-server)
  3. Add git remote 
     heroku git:remote -a open-event
  4. You can check if open event is added to git remote 
    $ git remote -v
heroku https://git.heroku.com/open-event.git (fetch)
heroku https://git.heroku.com/open-event.git (push)
origin https://github.com/fossasia/open-event-orga-server.git (fetch)
origin https://github.com/fossasia/open-event-orga-server.git (push)
  5. Now you can deploy changes to open-event application(You need a permissions 🙂 )

Why should you use a Heroku?

It’s great to deploy apps because you are able to share content in short time what I’ve done. Besides it’s very well documented so you can find there answers for most of your questions. Finally most of things you can configure using Heroku dashboard so it’s the best advantages of this tool.

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79 issues done in one week!

Have you ever wondered how to achieve such a result?

Screen Shot 2016-05-31 at 12.09.51I couldn’t believe that we’ve solved such many issues in Milestone 2. The 79 is 34% of all issues, isn’t it amazing? I think that defining what kind of project do we want to develop and what features should it have allows us to move quickly and cooperate with the whole team very effectively.

What you need to achieve similar score?

First of all, you need to prepare good document which help a whole team to get familiar with the project and its features. The most important part is to describe very precisely step by step a project flow, and features required to implement. It can help us to avoid obstacles, tie-ups and questions related to flow, because every developer is able to go through the document and find a desired answer.

Secondly, you need to define a target what are we going to achieve and when. Based on this info developers can define plan of work easily. We have divided 3 month period into 15 milestones. In each end of milestone we talk what we have achieved, what has been done, what hasn’t been done and what are we going to do in next week.

Daily, also works well in our team, because we are able to monitor what is currently happening in project. And you can quickly help if someone has a problem.

Flow of solving issues is very simple(Justin configured a CI). We have two branches – master and testing. Writing tests is essential to do before writing code. If tests are ready and passed successfully we can create a pull request. Then other developers review our code and finally if everything is ok we can merge changes with testing branch.

Continue Reading79 issues done in one week!

Wrapping up our first steps – Event Server, Material Design, Daily Scrum

The Event Organizer application has already the basic features and we can move to apply more advanced feature. But let explain me, what me and my friends have done recently.

Our application is already able to manage conferences and events. An owner can edit and change events in the way he/she wants to. And we have two version of this app for websites and for mobile phones(Android). The orga serv which I prepared share Json API to both Android and Web app. I guess it is really comfortable solution because it enables to share date between web and mobile app. Our app’s template style is based on material bootstrap, the same is used by Arnav in his application. It is very flat design.

Zrzut ekranu 2015-07-06 o 22.58.07
First Version of Open EVent Menu Bar

What I really like during this term is daily scrum, where we can share what we have already done, what are we going to do next, and what were the obstacles. Because of it, we can easily be in touch and avoid duplicating our work. We can also discuss and quickly choose the most useful solution. Duke and Mario accompany us and as always were ready to help with any trouble.

Arnav and Manan also organized a conference on their university. Many students were invited and discussed about taking part in open source projects. I regret not to having taken part in it, but India is so far from my country, that I could not get there.

I hope that the starting up part of this project will be also so developing and exciting, and we will finish it with a huge success. And all of us will be very proud, learn many new things, and improve our experience.

In the nearest future Arnav, Duke and me are going to create three environments: staging, production, and development. It helps us to organize our work. I am sure that we manage to do it.

Ok, so stay tuned. “Show must go on”! We don’t stop working! 😉

Continue ReadingWrapping up our first steps – Event Server, Material Design, Daily Scrum

How to create simply posts website in Flask framework?

Zrzut ekranu 2015-06-28 o 00.26.17

I have used Django framework so far, but because of my participation in Google summer of code. We decided to use something new. It was Flask. And Now I want to share it with you.

It is a microframework, which allows us in really short time create a nice app. I’d like to share my experience in this area to teach you how you can create an app. You will have a possibility to add, delete and update posts.

First of all you need to install flask framework via pip in your command line:

pip install flask

Next step it will be prepare a files structures
Zrzut ekranu 2015-06-28 o 00.44.54

My structure of files looks:

  • forms( will contain all form objects in our case only post form)
  • templates will contain all app views(listing posts and possibility to create post)

We want to manage posts, so we have to define database model Post in app.py. I only defined title and text fields. Zrzut ekranu 2015-06-28 o 00.49.04

Zrzut ekranu 2015-06-28 o 01.11.58

Next step will be create a routes. The main purpose of routes is to recognize urls and execute actions. We need four methods to display list of posts(index), delete post(delete_post), add post(new_post) and update post(edit_post)

That’s all to run your first posts application. Additionally I attach link to project on github, where you can trace whole project code.

Have a nice coding!

Continue ReadingHow to create simply posts website in Flask framework?

Adventure developing an Open Event Application

My adventure with the FOSSASIA organisation developing an Open Source event application has begun. I’m working in multicultural team and I feel very excited. It’s quite funny that while you are working, your team sleep. Our mentors of Fossasia are very helpful (@mariobehling and @dukeleto). Duke is a real magician. When I ask him for help, I find a solution before he response to me 🙂 But the truth is that When I’ve got a problem, they always try to show me a good direction.

 

Our application is intended to create events in a quick and comfortable way. It will have the ability to manage multiple tech conferences. Every user will able to see the latest conference in Web App or Android app. So in general we are triple team. Each of us is responsible for another part. Manan is responsible for Android application, Arnav for Web App while me for server which supplies an Api to Android and Web App. I guess that cooperation in our team is good! I greatly get along with guys.

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