Cache

Lesgo! uses AWS ElastiCache for caching.

Configuration

This is configurable in the src/config/cache.js. Or copy this file to that path.

export default {
  default: "memcached",
  connections: {
    memcached: {
      url: process.env.ELASTICACHE_MEMCACHED_URL || null,
      options: {
        autoDiscover: true,
      },
    },
  },
};

ElastiCache is disabled by default. To enable ElastiCache, follow the steps below.

1. Uncomment elastiCache.yml resource in serverless.yml

resources:
  - ${file(${self:custom.path.resources}/elastiCache.yml)}

1. Deploy application and retrieve ElastiCache node Endpoint on AWS Console.

yarn deploy -s development

1. Update relevant environment file in config/environments/ directory.

ELASTICACHE_MEMCACHED_URL="INSERT_ELASTICACHE_NODE_ENDPOINT_HERE"

Deploy your application again and you may now use ElastiCache.

Cache Usage

Import the cache module from Utils/cache.

To test the sample usage, uncomment samples.yml function in serverless.yml and deploy the application to a development environment.

Retrieving data from the cache

Utils/cache.get() will return data from given cache key.

cache.get(
  key: String, // cache key to fetch data from
): Promise;

import cache from "Utils/cache";

const data = await cache.get("foo");

Retrieving multiple data from the cache

Utils/cache.getMulti() will return multiple data from multiple cache keys.

cache.getMulti(
  keys: String[], // array of cache keys to fetch data from
): Promise;

Example Usage

import cache from "Utils/cache";

const cacheKeys = ["foo", "foo2", "foo3"];

const data = await cache.getMulti(["foo", "foo2", "foo3"]);

Storing items to the cache

You may use the set method on the cache util to store items to the cache.

import cache from "Utils/cache";

const cacheKey = "foo";
const cacheValue = "bar";
const cacheLifetimeInSeconds = 10;

const data = await cache.set(cacheKey, cacheValue, cacheLifetimeInSeconds);

Test sample usage with this url endpoint /samples/cache?method=set&key=sampleCacheKey&value=sampleCacheValue.

Deleting cache data

Utils/cache.del() will remove the cache key.

cache.del(
  key: String, // cache key to remove
): Promise;

Example Usage

import cache from "Utils/cache";

await cache.del("foo");

Deleting multiple cache data

Utils/cache.del() will remove the cache key.

cache.delMulti(
  keys: String[], // array of cache keys to remove
): Promise;

Example Usage

import cache from "Utils/cache";

await cache.delMulti(["foo", "foo2", "foo3"]);