Assets not loading in production for rails app - ruby-on-rails-3

Question

The current app I am running is working just fine in production on its ubuntu server. But now I've had to configure a Red Hat Enterprise Linux 5.5 server to deploy the app to and I am running into some issues. First of all some specs:
rails version: 3.2.11
ruby: 1.9.3-p194
http server nginx + unicorn
managing ruby environment with rbenv
deploy method: capistrano
My nginx.conf and unicorn config file are based on Ryan Bate's videos. So I managed to get almost everything configured. I can deploy, connect to the database, etc.. However, when I visit my app's page, all of the assets fail to load. And when I go into my console it says they failed because of a 403 Forbidden error. I checked and the assets are in the correct place: apps/my_app/shared/assets. But I keep getting this 403 error.
What I've tried so far:
checked the permissions to parent folders and the actual asset files. They all had at least read permissions for everyone
changed config.assets.compile to true
Followed instructions here rails deployment using nginx & unicorn: 403 forbidden error, which recommends removing the default files in conf.d and symlinking my custom nginx config file to /etc/nginx/conf.d as opposed to .../sites-enabled
Any thoughts or ideas why I am getting a 403?
Edit 1: add /etc/nginx/nginx.conf file
Not sure if this helps but this is what the nginx.conf file (under /etc/nginx) looks like (not my custom nginx file):
events {
worker_connections 1024;
}
#----------------------------------------------------------------------
# HTTP Core Module
#
# http://wiki.nginx.org/NginxHttpCoreModule
#
#----------------------------------------------------------------------
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
#
# The default server
#
server {
listen 80;
server_name _;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root /usr/share/nginx/html;
index index.html index.htm;
}
error_page 404 /404.html;
location = /404.html {
root /usr/share/nginx/html;
}
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
# Load config files from the /etc/nginx/conf.d directory
include /etc/nginx/conf.d/*.conf;
}
Also, I noticed that under /etc/nginx there are nginx.conf and nginx.conf.default files, does anyone know the difference? Maybe the issue could be there?
Edit 2: Add entry from nginx log file
So I found this in the nginx log file. So maybe it is a permissions issue that could be fixed with a chmod?
2013/03/24 20:50:53 [error] 10851#0: *5 open() "/home/webapp/apps/my_app/current/public/assets/application-db22bc3811b126e586f5e82e794e7ee4.css" failed (13: Permission denied)
Edit 3: Update /etc/nginx/nginx.conf
user nginx;
worker_processes 2;
# error_log logs/error.log;
# error_log logs/error.log notice;
# error_log logs/error.log info;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log;
sendfile on;
#tcp_nopush on;
keepalive_timeout 60;
gzip on;
include /etc/nginx/conf.d/*.conf;
# INSIDE THE /etc/ngin/conf.d/*.conf FILE #
server {
listen 80 default deferred;
# server_name example.com;
root /home/webapp/apps/my_app/current/public;
location ^~ /assets/ {
gzip_static on;
expires max;
add_header Cache-Control public;
}
try_files $uri/index.html $uri #unicorn;
location #unicorn {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://unicorn;
}
error_page 500 502 503 504 /500.html;
client_max_body_size 4G;
keepalive_timeout 10;
}
}

Answer 1

So I managed to fix this. In part to advice in this article http://nginxlibrary.com/403-forbidden-error/
for all the directories leading up to all the asset files, I set the directory permissions to chmod 775. And then for all the assets (application.js, etc...) inside apps/my_app/shared/assets I gave the files this permission chmod 775.
And that did the trick. In the article I linked to, the author mentions the need for the asset files to have both read and execute permissions, not just read.