wkhtmltopdf doesn't work when deployed in heroku python app using(Flask) pdfkit and wkhtmltopdf

Question

I am in a process of converting HTML files to pdf in python and attach these pdf files to mail and process it

• I've installed pdfkit(0.6.1), wkhtmltopdf(0.2) and also wkhtmltopdf for windows. And added wkhtmltopdf bin path. It is working in my local system without any issue here is my code

  url=""
  PDF = pdfkit.from_url(url, False)
  result= SendPDFtomail(PDF)
  return result 
  

• When I tried to push the same code into heroku by adding the buildpack for wkhtmltopdf and buildpacks for my application are

    1. heroku/python
    2. https://github.com/dscout/wkhtmltopdf-buildpack.git
  

• When i push my build to heroku

     git push heroku master
     Counting objects: 3, done.
     Delta compression using up to 4 threads.
     Compressing objects: 100% (3/3), done.
     Writing objects: 100% (3/3), 336 bytes | 84.00 KiB/s, done.
     Total 3 (delta 2), reused 0 (delta 0)
     remote: Compressing source files... done.
     remote: Building source:
     remote:
     remote: -----> Python app detected
     remote:  !     The latest version of Python 3.6 is python-3.6.6 (you 
     are using python-3.6.4, which is unsupported).
     remote:  !     We recommend upgrading by specifying the latest version 
     (python-3.6.6).
     remote:        Learn More: 
     https://devcenter.heroku.com/articles/python-runtimes
     remote: -----> Installing requirements with pip
     remote:
     remote: -----> wkhtmltopdf app detected
     remote: -----> Moving wkhtmltopdf binaries to /app/bin
     remote: -----> Discovering process types
     remote:        Procfile declares types -> web
     remote:
     remote: -----> Compressing...
     remote:        Done: 103.8M
     remote: -----> Launching...
     remote:        Released v19
     remote:        https://XXXXXXX.herokuapp.com/ deployed to 
     Heroku
     remote:
     remote: Verifying deploy... done.
  

my app was deployed without any issues and when am running the code in Heroku I am getting the error

      Exception :No wkhtmltopdf executable found: "b''"
      If this file exists please check that this process can read it. 
      Otherwise please install wkhtmltopdf - 
      https://github.com/JazzCore/python-pdfkit/wiki/Installing-wkhtmltopdf

which is the same error I received when I didn't add the wkhtmltopdf path to the system, As we can see in my build Moving wkhtmltopdf binaries to /app/bin, how can I make my Heroku configure to this wkhtmltopdf binary path? how can we use config vars in Heroku to make this work

I've tried this generating-pdfs-wkhtmltopdf-heroku but couldn't get it. And wherever I search am getting solutions for ruby that we need to configure the gem file, how can I do it in python

I've been working on it from past two days, Please help me out

Thanks in advance

Meghana Goud

Answer 1

I am now using OSX and heroku to deploy my flask app. When deployed the heroku wkhtmltopdf binary is in ./bin/wkhtmltopdf. So I wrote this code to deal with this.

if (platform.system() == 'Darwin'):
    config = pdfkit.configuration()
else:
    config = pdfkit.configuration(wkhtmltopdf='./bin/wkhtmltopdf')