hapi-redis-output-cache

Redis-backed output cache plugin for Hapi

Usage

$ npm i hapi-redis-output-cache --save

var server = new (require('hapi').Server)();
server.connection({ port: 3000 });

server.register([
    {
        register: require('hapi-redis-output-cache'),
        options: {
            host: '127.0.0.1',
            staleIn: 30,
            expiresIn: 60
        }
    }
], function (err) {
    if (err) {
        console.error('Failed to load plugin:', err);
    }

    server.start();
});

Configuration

host - hostname or IP address of the Redis server
port - (optional) port of the Redis server; defaults to 6379
varyByHeaders - (optional) an array of headers to be used for generating cache key; defaults no none
partition - (optional) string to prefix cache keys with, useful for shared redis instances
staleIn - number of seconds until the cached response will be considered stale and marked for regeneration
expiresIn - number of seconds until the cached response will be purged from Redis
onCacheMiss - (optional) function(request){ ... } invoked on each cache write; useful for tracking cache miss rates in a service
onError - (optional) function which is invoked on each Redis error

Route Settings

By default, output caching is disabled. To enable it for a specific route, set cacheable: true in the route settings:

server.route({
    method: 'GET',
    path: '/',
    handler: function (request, reply) {
        return reply('hello world');
    },
    config: {
        plugins: {
            'hapi-redis-output-cache': {
                cacheable: true
            }
        }
    }
});

To enable for all routes, set cacheable: true in the server config:

var server = new (require('hapi').Server({
    connections: {
        routes: {
            plugins: {
                'hapi-redis-output-cache': {
                    cacheable: true
                }
            }
        }
    }
});

Additionally, you can override certain properties on a per-route basis:

server.route({
    method: 'GET',
    path: '/',
    handler: function(request, reply){
        return reply('hello world');
    },
    config: {
        plugins: {
            'hapi-redis-output-cache': {
                cacheable: true,
                varyByHeaders: ['accept-language'],
                staleIn: 60,
                expiresIn: 120,
                partition: 'foo'
            }
        }
    }
});

Miscellaneous

Output cache metadata is injected into each request and can be access via req.outputCache:

isStale: boolean value indicating whether the cache is stale
data: object representing cached response (available even when stale)

Release History

v2.0.2 (2015-07-22)
- fixed caching bug
v2.0.1 (2015-07-13)
- updated dependencies
v2.0.0 (2015-04-10)
- added partition option
v1.0.3 (2015-03-31)
- bug fixes
v1.0.0 (2015-03-30)
- implemented a more sophisticated freshness mechanism which allows stale and expired data to be handled separately
- implemented a whitelist of request headers to be used for generating cache key to provide more fine-grained control over keys
v0.2.1 (2015-03-30)
- fixed handling of responses with failed joi validation
v0.2.0 (2015-03-30)
- fixed cache key algorithm
v0.1.0 (2015-03-29)
- initial release

opentable / hapi-redis-output-cache