python-django Ghostscript apache problem - apache

Question

When I run my app, that converts pdf to png, from django server, the conversion works fine. But when I run this from an apache server, I am getting this error: GhoscriptError: Fatal. Reading from the sterr of ghostscript, it says
Initialization file gs_init.ps does
not begin with an integer.
It seems an initialization error for me, but I have no idea how to fix this.
Using Ubuntu by the way. gs folder is in the path, so Im not sure if that is causing the problem.
Here's my code that generates the images
def PDF_to_png(input,output):
args = [
"-dSAFER",
"-dBATCH", "-dNOPAUSE", "-sDEVICE=png16m",
"-r300",
"-sOutputFile=" + os.path.join(output,input.file_name_without_extension)+"_%d.png",
input
]
ghostscript.Ghostscript(*args)

Answer 1

The error is telling you that the file gs_init.ps which is normally found in gs/Resource/Init/ is not valid. From the header of the file:
------------------------------------------------------------------------
% Interpreter library version number
% NOTE: the interpreter code requires that the first non-comment token
% in this file be an integer, and that it match the compiled-in version!
902
------------------------------------------------------------------------
You can build GS with the resources built-in or on disk, I don't know which build you get with Ubuntu but it sounds like either there is a gs_init.ps in the GS path which has been damaged. This probably means you are using a version with the resources on disk.
You should first try just starting up Ghostscript. If that works then it's something to do with the environment which is different when you run the failing instance. Look for environment variables which begin GS_ (especially *GS_LIB*). You should also try actually defining where GS should look on the command line by including something like :
-I/usr/src/gs/Resource
This I ncludes the specified directory as a search path for Ghostscript (NB GS does not use the PATH environment variable). GS will search here for initialisation files first before proceeding on its fall back mechanism.