upload files from your grunt to nginx without backend or upstream

grunt-task.js

grunt.registerMultiTask("upload", function(){
  var async = require("async");
  var request = require("request");
  var path = require("path");
  var fs = require("fs");
  var done = this.async();
  var files = [];
  var url = this.data.url;
  var fns = [];
  
  this.files.forEach(function( files ){
    files.src.forEach(function(file){
      var fullName = path.join(files.cwd, file);
      fns.push(function(cb){
        var req = request.post({
          url: url + file,
          headers: {
            "Content-Length": fs.statSync(fullName).size
          }
        },cb);
        fs.createReadStream(fullName)
          .pipe(req)
          .on("error",cb);
      });
    });
  });
 
  async.parallelLimit(fns, this.data.limit||5, done);
});

gruntfile.js

/* if you have a directory structure like this:
|public
|--images
|-----image1.jpg
|--v/v1.2.3
|----main.js
|----stylesheets
|------style.css
*/
 
grunt.initConfig({
  upload: {
    build: {
      files: [{
        expand: false,
        src: [ "images/*", "v<%=pkg.version%>/**/*" ],
        cwd: "public",
        filter: "isFile"
      }],
      url: "http://127.0.0.1:8000/your-project/"
    }
  }
});

nginx.conf

server {
    listen 8000;
    location / {
        limit_except POST          { deny all; }
        client_body_buffer_size    10M;
        lua_need_request_body on;
        content_by_lua '
            local file
            local filename
            filename = "/var/www/cdn" .. ngx.var.uri
            os.execute("mkdir -p `dirname " .. filename .. "`")
            file = io.open(filename,"w")
            file:write(ngx.req.get_body_data())
            file:close()
            ngx.status = ngx.HTTP_OK
        ';
    }
}