rails 4：Errno :: ENOENT（没有这样的文件或目录@ rb_sysopen - / assets /

Question

I've just deployed my app to heroku and I'm having a lot of trouble trying to read some assets.

I am trying to dynamically load some css from multiple files, then recompile them with some changes later. The line that keeps breaking is the first file load:

@css_asset_bootstrap = File.open(ActionController::Base.helpers.asset_path('bootstrap.css'), "r").read

which generates this error:

2015-04-07T23:30:50.098831+00:00 app[web.1]: Errno::ENOENT (No such file or directory @ rb_sysopen - /assets/bootstrap-2d25733981c30e34bd9aa0fb75388f08.css):

I've tried a lot of things, including moving all my assets to aws cloudfront. Is there a way to get around this? Works perfectly in development environment.

Just to confirm a few things. I've successfully precompiled and uploaded the file. The file definately exists as I can see it in

heroku run bash
cd /public/assets/

I can also see it when I moved the assets to cloudfront.

Thanks.

edit 1: Not sure if this is important information, but with the file on cloudfront, I can run heroku run bash to start a shell session on heroku. Then I can:

curl http://xxx.cloudfront.net/assets/bootstrap-2d25733981c30e34bd9aa0fb75388f08.css

And get the file ok. I was thinking maybe it was a permissions error but everything is set to public and it all seems to work from heroku to the aws server.

Answer 1

You're asking for the file from a relative path, which might not always work. Try absolute:

@css_asset_bootstrap = File.open(Rails.root + ActionController::Base.helpers.asset_path('bootstrap.css'), "r").read

Another possibly bigger problem is that Heroku has an ephemeral filesystem, and so any changes you write to it can be obliterated at any time when the dyno is culled.

Answer 2

In my case, using a virtual machine Rails.root give me this: '/home/vagrant/projects/.../my-nice-app' what is totally uncool.

I use instead request.url with give me: 'http://localhost:3000/ ' what it is exactly what I want.