Meteor edit audio files on the server using ffmpeg

Hi there
I am building a Meteor application to split uploaded audio files
I upload the audio files and store them using GridFS

child = Npm.require(‘child_process’);

var fs = Npm.require('fs');


storagePath= fs.realpathSync(process.env.PWD+'/audio');
StaticServer.add('/audio', clipsPath);

and then using a method i split the audio file using
child.exec(command);

the command is the ffmpeg command used to cut the source audio file and store it on the storagePath

the application worked fine locally but when I tried to deploy it to digital ocian i got errors , stating that the file /audio doesnot exist
I use mupx to deploy and the error appears after “verifying deployment”

here is the error

    -----------------------------------STDERR-----------------------------------
    eteor-dev-bundle@0.0.0 No README data
    => Starting meteor app on port:80

    /bundle/bundle/programs/server/node_modules/fibers/future.js:245
                                                    throw(ex);
                                                          ^
    Error: ENOENT, no such file or directory '/bundle/bundle/audio'
        at Object.fs.lstatSync (fs.js:691:18)
        at Object.realpathSync (fs.js:1279:21)
        at server/startup.js:10:20
        at /bundle/bundle/programs/server/boot.js:249:5
    npm WARN package.json meteor-dev-bundle@0.0.0 No description
    npm WARN package.json meteor-dev-bundle@0.0.0 No repository field.
    npm WARN package.json meteor-dev-bundle@0.0.0 No README data
    => Starting meteor app on port:80

    /bundle/bundle/programs/server/node_modules/fibers/future.js:245
                                                    throw(ex);
                                                          ^
    Error: ENOENT, no such file or directory '/bundle/bundle/audio'
        at Object.fs.lstatSync (fs.js:691:18)
        at Object.realpathSync (fs.js:1279:21)
        at server/startup.js:10:20
        at /bundle/bundle/programs/server/boot.js:249:5

    => Redeploying previous version of the app

    -----------------------------------STDOUT-----------------------------------

    To see more logs type 'mup logs --tail=50'

    ----------------------------------------------------------------------------

the main quistion is , how to i generate an output file using ffmpeg command and store it in a place where I can access it and display it on the browser?

should I use CollectionFS ?
if so , how , this problem is killing me

Are you sure you are writing to /public?

no I am not writing to public , I am writing to the project’s root directory

Is ffmpeg properly installed on the server? I know that with mupx you have to manually add external programs to the server via docker (I had to do this with graphicsmagick for photo cropping)