I am using a gulp task to deploy my application, like this (in this example I am omitting the real values)

```
gulp.task('deploy', function () {
return gulp.src(config.deployFiles)
        .pipe(rsync({
            root: 'build/',
            hostname: 'hostname',
            username: 'username',
            destination: 'destination'
     }));});

```

However,the command fails with 

gulp-rsync: Permission denied (publickey). 

Note: I can access the remote server through ssh, the point is how to tell cygwin to use the right ssh key so that gulp-rsync can use it?