deploy to s3

gistfile1.js

   grunt.registerMultiTask('deploy', 'deploy program to cloud', function() {                                                                  
      var pkgcloud = require('pkgcloud')                                                                                                       
        , walk = require('walk')                                                                                                               
        , fs = require('fs')                                                                                                                   
        , done = this.async()                                                                                                                  
        , self = this;                                                                                                                         
                                                                                                                                               
      grunt.log.writeln('Prepare upload to cloud (Prepare deploy configuration)');                                                             
                                                                                                                                               
      var content, amazon;                                                                                                                     
      try {                                                                                                                                    
        content = JSON.parse(fs.readFileSync('./s3.json'));                                                                               
        amazon = pkgcloud.storage.createClient({                                                                                               
          provider: 'amazon',                                                                                                                  
          key: content.secret,                                                                                                                 
          keyId: content.key                                                                                                                   
        });                                                                                                                                    
      } catch (e) {                                                                                                                            
        grunt.fail.fatal('Can not get s3 key to deploy files');                                                                                
      }                       

      var walker = walk.walk(self.data.from);                                                                                                  
      walker.on('file', function(root, fileStat, next) {                                                                                       
        var readpath = root + '/' + fileStat.name;                                                                                             
        var prefix = root.substr((self.data.from.length + 1));                                                                                 
        var filepath = '';                                                                                                                     
        if (prefix === '') {                                                                                                                   
          filepath = fileStat.name;                                                                                                            
        } else {                                                                                                                               
          filepath = prefix + '/' + fileStat.name;                                                                                             
        }                                                                                                                                      
                                                                                                                                               
        fs.createReadStream(readpath).pipe(amazon.upload({                                                                                     
          container: self.data.to,                                                                                                             
          remote: filepath                                                                                                                     
        }, function(err) {                                                                                                                     
          if (err) {                                                                                                                           
            grunt.log.error(readpath + ' upload failed!');                                                                                     
          } else {                                                                                                                             
            grunt.log.error('Upload from ' + readpath);                                                                                        
            grunt.log.error('to ' + filepath);                                                                                                 
          }                                                                                                                                    
          next();                                                                                                                              
        }));                                                                                                                                   
                                                                                                                                               
      });                   

      walker.on('errors', function(root, fileStat, next) {                                                                                     
        grunt.log.error('Can not read ' + fileStat.name + ' correctly');                                                                       
        next();                                                                                                                                
      });                                                                                                                                      
                                                                                                                                               
      walker.on('end', function() {                                                                                                            
        grunt.log.error('Deploy all programs to cloud');                                                                                       
        done();                                                                                                                                
      });                                                                                                                                      
                                                                                                                                               
    }); 

grunt config

deploy: {
  from: 'FILE_PATH',
  to: 'S3_BUCKET'
}