lazy-redis-cache

  cache.wrap({
        key: 'test',
        value: function (cb) {
            var value = 'Hello World"
            cb(null, value);
        },
        ttl: 24 * 60 * 60, //TTL in seconds
        lazy: true
      }, function(err,cached){
          console.log(cached);
      };
  )

Dynamic TTL

cache.wrap({
      key: 'test',
      value: function (cb) {
          var movie = {
          name:'interstellar',
          year:2015
          }
          cb(null, value);
      },
      ttl: function (cached) {
        if (cached.year > 2014)
          return 24 * 60 * 60;
        else
          return 30 * 24 * 60 * 60;
      },
      lazy: true
    }, function(err,cached){
        console.log(cached);
    };
  )