For enabling push notification on pushd server, you need to get a file with .p12 extension and .cer certificate file. For pushd to work you need to generate a .pem file and give its path in push configuration(`/etc/pushd/pushd.conf`).

We need to generate 2 pem files one called apns-cert.pem (generated from .cer file) and the other called apns-key.pem (generated from .p12 file).

To generate .pem file use openssl command, with the format below:

openssl pkcs12 -in YOUR_KEY.p12 -out apns-key.pem -nodes

NOTE: it may ask you for the password, enter the given password by whom that gave you the p12 file.

-in set your input file name and -out sets your output file name which will be generated.

And now generate the key pem file:

openssl x509 -in cert.cer -inform DER -outform PEM -out apns-cert.pem

Restart the pushd and check for any error in /var/log/pushd.

#pushd #openssl #p12 #cer #pem #push

lowercase/uppercase a function, variable or a string in PyCharm by using:

OS X: Command+Shift U

#pycharm #lowercase #uppercase

Download a static file from a remote URL by using requests in python:

# author -> Roman Podlinov
 def download_file(url):
     local_filename = url.split('/')[-1]
     r = requests.get(url, stream=True)
     with open(local_filename, 'wb') as f:
         for chunk in r.iter_content(chunk_size=1024):
             if chunk: # filter out keep-alive new chunks
                 f.write(chunk)
     return local_filename

NOTE: stream=True parameter is used for returning large files in chunk and save it into a file

#python #requests #stream #large_file #download

Modern Linux Administration
by Sam R. Alapati”

#ebook #epub #book #linux #sysadmin

To find all of users ids:

ps -eo uid

#linux sysadmin #ps #users #uid

Django tutorials will be published today or the day after, sorry for the delay. 🙈

#mail #mail_server #550 #server_error

In order to create a debian package from your shell script do as follow:

Let's consider our package name is dangling. We need to create 2 folders, first is called dangling and the second is DEBIAN which is inside of the dangling folder:

mkdir helloworld && mkdir helloworld/DEBIAN

You can copy the files into your package with the full paths on the destination filesystem. E.g. if you want to put a file in /usr/local/bin/ you put it in dangling/usr/local/bin/:

mkdir -p dangling/usr/local/bin
 cp /usr/local/bin/dangling.sh dangling/usr/local/bin/

In your DEBIAN directory (created at the begining of the post), create a control file with the below content:

<span class="Apple-style-span" style="font-family: Consolas, Monaco, monospace; font-size: 12px; white-space: pre;">Package: dangling
 </span><span class="Apple-style-span" style="font-family: Consolas, Monaco, monospace; font-size: 12px; white-space: pre;">Version: 0.1
 </span><span class="Apple-style-span" style="font-family: Consolas, Monaco, monospace; font-size: 12px; white-space: pre;">Maintainer: Alireza Hoseini
 </span><span class="Apple-style-span" style="font-family: Consolas, Monaco, monospace; font-size: 12px; white-space: pre;">Architecture: all
 </span><span class="Apple-style-span" style="font-family: Consolas, Monaco, monospace; font-size: 12px; white-space: pre;">Description: would wipe all docker dangling volumes out

NOTE: These are the mandatory fields in the control file.

Now build the package using dpkg-deb:

dpkg-deb --build dangling

This creates a dangling.deb file, which you can now install on any Debian installation with following command:

dpkg -i dangling.deb

#debian #deb #create #package #dpkg #build

In case you want to add a custom font to OS X, you need to go to /Library/fonts and paste your custom fonts in this folder. No need to restart or logout.

reference: https://support.apple.com/en-us/HT201722

#apple #osx #font #fonts

Remove all stopped containers.

docker rm $(docker ps -a -q)

#docker #rm #ps

DJANGO

Let's do a little bit more by fetching data from database and pass them to views in Django.

For now we make a change in polls/views.py in index function to get data from Question model and return it as an HTTP response object. At first let's import the model:

from .models import Question

And now in index function write the below code:

latest_question_list = Question.objects.order_by('-pub_date')[:5]
output = ', '.join([q.question_text for q in latest_question_list])
return HttpResponse(output)

The code above gets the last 5 questions and on the second line question_text fields for those que
stions are joined together by comma and finally returned as an HTTP response.

Now if you head over to http://127.0.0.1:8000/polls/ you would see the result of question texts bound together by co
mma.

#python #django #query #django_part9

Here we aim to design templates and render them to interact with Django the way it likes! We try to isolate the page's design.

Create a folder called templates in polls directory (this is the default folder name where django will look for app templates). Inside of templates create polls directory and inside of it create index.html file. So your templates are in path polls/templates/polls/index.html.

We have polls inside of templates folder to render templates in the format of loader.get_template('polls/index.html').

NOTE: if you don't create polls subdirectory inside of templates and you have templates we the same name in different apps (in the same project) you would encounter bizarre problems. DON'T DO THAT! (Django will choose the first template it finds whose name matches)

Now put the below code in polls/templates/polls/index.html:

{% if latest_question_list %}
    <ul>
    {% for question in latest_question_list %}
        <li><a href="/polls/{{ question.id }}/">{{ question.question_text }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>No polls are available.</p>
{% endif %}

OK now do as follow in index function in polls/views.py for template rendering:

from django.http import HttpResponse
from django.template import loader
from .models import Question


def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    template = loader.get_template('polls/index.html')
    context = {
        'latest_question_list': latest_question_list,
    }
    return HttpResponse(template.render(context, request))

Note that we have imported loader from django.template.

As you can see above, we have rendered the template with our variables (context) and passed it to http response object. We have used django.template module to render templates.

I've got the below result (next picture) what about you?

#django #loader #render #templates #django_part10

https://www.confluent.io/blog/apache-kafka-goes-1-0/

#kafka #version1 #confluent

PyData Amsterdam 2017

This talk gives an overview of the Neo4j graph database and the Cypher query language from the point of view of a Python user. We'll look at how to run queries and visualise or extract those results into software such as Pandas. We'll also explore the property graph data model and look at how it differs from other data models.

Graph databases offer a fresh perspective on data modelling and one that is often closer to the real world than a traditional RDBMS. In this talk, we'll look at how to work with Neo4j's property graph data model from the point of view of a Python user, how this model differs from other database models and we'll also show how to integrate the Cypher query language into a Python application.

This talk will (hopefully!) contain a couple of live demonstrations. We'll explore how to integrate Cypher query results with data analysis tools such as Pandas as well as how to visualise graph data through the Neo4j browser.


#neo4js #python #pandas #pyvideo

How much do you know about python traceback? Here we will dive deep into this concept.

What is a traceback?
This module provides a standard interface to extract, format and print stack traces of Python programs.

It acts a lot like a python interpreter when it print a stack trace. traceback module has many functions, we will review some of them here.

traceback.print_exc():
Print exception information and up to limit stack trace entries from the traceback tb to file. This is a shorthand for print_exception(sys.exc_type, sys.exc_value, sys.exc_traceback, limit, file).

traceback.format_exc():
This is like print_exc(limit) but returns a string instead of printing to a file.

A sample traceback usage derived from python documentation:

import sys, traceback

 def run_user_code(envdir):
     source = raw_input(">>> ")
     try:
         exec source in envdir
     except:
         print "Exception in user code:"
         print '-'*60
         traceback.print_exc(file=sys.stdout)
         print '-'*60

 envdir = {}
 while 1:
     run_user_code(envdir)

#python #traceback #exception #format_exc #print_exc

In os x you can use repeat command to repeat a command! If you want to send multiple get request using cURL:

repeat 10 curl https://www.google.com

In Linux we can do the same using for loop:

for i in {1..12}; do echo 'test'; done

#osx #linux #repeat #for

https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet

#reference #markdown #github