Rails + Passenger：无法执行Shell命令

Question

I've setup Apache + Rails + Passenger and the app loads correctly (for the most part). The application uses Tesseract and GS to convert PDFs into images and then take their text and insert it into the database.

When I test the application using rails s, everything functions normally, but when I try to run some of the functions from the passenger instance, I get the following error in my apache log:

App 14107 stderr: sh: tesseract: command not found

The error occurs for the following code:

%x(gs -dNOPAUSE -dBATCH -sDEVICE=pngalpha -r300 -sOutputFile="page%03d".png #{self.doc.path})
%x(for f in page*.png ; do tesseract $f $f.out; done)

There is nothing in my rails production.log file that indicates any errors.

I'm running CentOS 6 and I built my tesseract using this guide: https://www.simpleservers.co.uk/clients/whmcs/knowledgebase/600/Install-Tesseract-OCR-libs-from-sources-in-Centos.html

The user that passenger runs as can also run the command tesseract. I checked in its console, but for some reason, passenger can't run it. Do I need to enable it for the apache user somehow?

Thanks

Answer 1

Thanks to shellter for pointing me in the right direction. This is what fixed the issue for me:

Apache couldn't call tesseract, so I had to add it to its path. Based on this answer ( How to add path to Apache ), I went to /etc/sysconfig/httpd (this is CentOS specific) and added the line:

export PATH=<the path>

To get the path, I just ran this in the console:

env

And took the output for the PATH.