HEROKU Node Canvas

usage:

1. create a heroku app in cedar:

heroku create --stack cedar

2. set environment variables

create a .env file in your application with this contents:

LD_PRELOAD='/app/node_modules/canvas/cairo/libcairo.so /app/node_modules/canvas/lib/libpixman-1.so.0 /app/node_modules/canvas/lib/libfreetype.so.6'
LD_LIBRARY_PATH=/app/node_modules/canvas/cairo

• LD_PRELOAD will tell heroku to always preload those libs
• LD_LIBRARY_PATH will tell heroku where to find aditional dinamic libs

Note on #2:

If the .env file doesn't work for you, alternatively, you can try:

$ heroku config:add LD_PRELOAD='/app/node_modules/canvas/cairo/libcairo.so /app/node_modules/canvas/lib/libpixman-1.so.0 /app/node_modules/canvas/lib/libfreetype.so.6' --app your-app
$ heroku config:add LD_LIBRARY_PATH=/app/node_modules/canvas/cairo --app your-app

Final Notes

If you ever need to "re-install" a library like this on heroku, you'll need to either

• Destroy and recreate the app on heroku
• Or, up the version number in the package.json

Heroku won't re-install, it will only pull from cache, if the version number is the same.

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