Rails: CSS background image not showing up on rails site

Question

I'm trying to use the background-image css property with a website I'm building with Ruby on Rails.

I've tried several different variations of background-image: url, background: url, with and without quotations, and several paths to the image. The image is currently located in app/assets/images/upload.png.

background: url(upload.png);

custom.css.scss

/* UNIVERSAL */

body {
background-color: black;
padding-top: 8px;
width: 800px;
margin-left: auto;
margin-right: auto;
font-family: arial, sans-serif;
font-size: 16px;
}

.content {
background-color: white;
-moz-border-radius: 10px;
-webkit-border-radius: 10px;
-khtml-border-radius: 10px;
border-radius: 10px;
padding: 1px 15px;
}

h2 {
font-size: 18px;
}

p {
font-size: 16px;
}   

ol {
font-size: 16px;
}


/* NAVIGATION */

ul {
padding: 0px;
}

#navtop {
float: right;
display: inline-block;
position: relative;
bottom: 47px;
right:4px;
letter-spacing:1px;
}

#topnavcontainer {
margin-bottom: -40px;

}

#navtop li, #navbottom li, #navbuttons li {
display: inline;
margin: 0px;
padding: 0px;
}

#navbuttons {
word-spacing: 25px;
position: relative;
left: 400px;
bottom: 60px;
display: inline-block;
}

#navbottom {
text-align: center;
word-spacing:90px;
letter-spacing:1px;
margin-top:25px;
}

#navtop a:link, #navbottom a:link, #navtop a:visited, #navbottom a:visited  {
text-decoration: none;
font-size: 12px;
color: #999999;
}

#navtop a:hover, #navbottom a:hover {
color: white;
}

#uploadbutton a:link, #uploadbutton a:visited, #viewbutton a:link, #viewbutton a:visited  { 
text-decoration: none;
border-style:solid;
border-width:3px;
border-color:#666666;
padding: 5px;   
color: white;
font-size: 14px;
font-weight: bold;
letter-spacing:2px;
}

#uploadbutton a:hover {
color: #FF0000;
}

#viewbutton a:hover {
color: #0066FF;
}   

/*style the main menu*/
.myMenu {
margin:0;
padding:0;
text-align: left;
}

.myMenu li {
list-style:none;
float:left;


}

.myMenu li a:link, .myMenu li a:visited {
display:block;
text-decoration:none;

padding: 0.5em 1em;
margin:0;


}

.myMenu li a:hover {
background-color:black; 
}

/*style the sub menu*/
.myMenu li ul {
position:absolute;
visibility:hidden;
margin:0;
padding:0;
}

.myMenu li ul li {
display:inline;
float:none;
}

.myMenu li ul li a:link, .myMenu li ul li a:visited {
background-color:black;
width:55px;
}

.myMenu li ul li a:hover {
background-color:#999999;
}

/* HOME PAGE */

#homepage {
text-align: center;
}

#homeheadline {
color: white;
background-color: #333333;
font-weight:normal;
border-style:solid;
border-width:6px;
border-color:#333333;
letter-spacing:1px;
margin-bottom: 45px;
}

a#clickhere , a#clickhere:visited {
text-decoration: none;
color: #0066FF;
}

#videotitle {
color: #FF0000;
position: absolute;;
bottom: 70px;
display: inline;
font-size: 19px;
left: 60px;
}

#videolist {
position: absolute;
left: 40px;
display: inline-block;
}

#audiencetitle {
color: #0066FF;
position: absolute;
bottom: 70px;
left: 340px;
display: inline;
font-size: 19px;
}

#audiencelist {
position: absolute;
display: inline-block;
left: 320px;
}

a.greenbutton, a.greenbutton:visited, {
font-size: 14px;
color: white;
font-weight: bold;
text-decoration: none;
background-color: #009900;
border-style:solid;
border-width:7px;
border-color:#009900;
letter-spacing:1px;
}

#homead {
margin-bottom: 25px;
margin-top: 45px;
display: block;
}

#lists {
width: 538px;
height: 100px;
position: relative;
margin-bottom: 35px;
margin-left: auto;
margin-right: auto;
text-align: left;
}

/* FORMS */

.greenbutton {
font-family: arial, sans-serif;
font-size: 14px;
color: white;
font-weight: bold;
text-decoration: none;
background-color: #009900;
border-style:solid;
border-width:3px;
border-color:#009900;
letter-spacing:1px;
margin-bottom: 40px;
}

.textinput {
border: 1px solid #bbb;
height: 18px;
width: 300px;
margin-bottom:30px;
}

.signform {
text-align: center;
width:300px;
margin-left: auto;
margin-right: auto;

}

.signformfields {
text-align: left;
}

#error_explanation {
color:#f00;
font-size: 16px;
ul { list-style: none;
   margin: 0 0 18px 0;
   }
}

.field_with_errors {
 @extend .control-group;
 @extend .error;
 }

/* Upload Menu */

#uploadpage {
height: 580px;

}
.uploadnav ul {
list-style-type: none;
}

.uploadnav {
width: 200px;
text-align: center;
float:left;


}

.uploadbox {
background-color: black;
background-image: url( image_path ("upload.png"));
border-style:solid;
border-width:25px;
border-color: black;
margin-top: 20px;

}

.uploadgreybox {
background-color: #CCCCCC;
border-style:solid;
border-width:25px;
border-color: #CCCCCC;
margin-top: 20px;
}

.uploadtext {
color: white;
background-color: black;
padding: 5px;
}

.uploadgreytext {
color: #666666;
background-color: #CCCCCC;
padding: 5px;
}



.uploadpagecontent {

float:right;
}

Answer 1

The most correct way:

background-image: url(<%= asset_path 'upload.png' %>)

See the Guide for details: http://guides.rubyonrails.org/asset_pipeline.html#coding-links-to-assets (sec. 2.2.1 CSS and ERB)

NOTE: If you're doing this in your application.css then add .erb extension to it to become application.css.erb

Answer 2

if somebody comes by and still looking for an answer and you're using SASS and bootstrap, you can try

background: image-url('bgImage.jpg');

that worked for me. You can as well take a look on http://guides.rubyonrails.org/asset_pipeline.html#coding-links-to-assets as jdoe mentioned.