A simple API response caching middleware for Express/Node using plain-english durations.
Supports any Keyv-compatible storage backend
I added the ability to use keyv storage backends.
Why?
Because route-caching of simple data/responses should ALSO be simple.
Usage
To use, simply inject the middleware (example: apicache.middleware('5 minutes', [optionalMiddlewareToggle])
) into your routes. Everything else is automagic.
Cache a route
import express from 'express'
import apicache from 'apicache'
let app = express()
let cache = apicache.middleware
app.get('/api/collection/:id?', cache('5 minutes'), (req, res) => {
res.json({ foo: 'bar' })
})
Cache all routes
let cache = apicache.middleware
app.use(cache('5 minutes'))
app.get('/will-be-cached', (req, res) => {
res.json({ success: true })
})
Use with Keyv storage
import express from 'express'
import Keyv from 'keyv'
import apicache from 'apicache'
let app = express()
let cacheWithRedis = apicache.options({
storage: new CacheStorage(new Keyv('redis://user:pass@localhost:6379')),
}).middleware
let cacheWithPostgres = apicache.options({
storage: new CacheStorage(new Keyv('postgresql://user:pass@localhost:5432/dbname')),
}).middleware
app.get('/will-be-cached-with-redis', cacheWithRedis('5 minutes'), (req, res) => {
res.json({ success: true })
})
app.get('/will-be-cached-with-pg', cacheWithPostgres('5 minutes'), (req, res) => {
res.json({ success: true })
})
Cache grouping and manual controls
import apicache from 'apicache'
let cache = apicache.middleware
app.use(cache('5 minutes'))
app.get('/api/:collection/:item?', (req, res) => {
req.apicacheGroup = req.params.collection
res.json({ success: true })
})
app.get('/api/cache/performance', (req, res) => {
res.json(apicache.getPerformance())
})
app.get('/api/cache/index', (req, res) => {
res.json(apicache.getIndex())
})
app.get('/api/cache/clear/:target?', (req, res) => {
res.json(apicache.clear(req.params.target))
})
Use with middleware toggle for fine control
const onlyStatus200 = (req, res) => res.statusCode === 200
const cacheSuccesses = cache('5 minutes', onlyStatus200)
app.get('/api/missing', cacheSuccesses, (req, res) => {
res.status(404).json({ results: 'will not be cached' })
})
app.get('/api/found', cacheSuccesses, (req, res) => {
res.json({ results: 'will be cached' })
})
let cache = apicache.options({
headers: {
'cache-control': 'no-cache',
},
}).middleware
let cache5min = cache('5 min')
API
apicache.options([globalOptions])
- getter/setter for global options. If used as a setter, this function is chainable, allowing you to do things such as... say... return the middleware.apicache.middleware([duration], [toggleMiddleware], [localOptions])
- the actual middleware that will be used in your routes. duration
is in the following format "[length][unit]", as in "10 minutes"
or "1 day"
. A second param is a middleware toggle function, accepting request and response params, and must return truthy to enable cache for the request. Third param is the options that will override global ones and affect this middleware only.middleware.options([localOptions])
- getter/setter for middleware-specific options that will override global ones.apicache.getPerformance()
- returns current cache performance (cache hit rate)apicache.getIndex()
- returns current cache index [of keys]apicache.clear([target])
- clears cache target (key or group), or entire cache if no value passed, returns new index.apicache.newInstance([options])
- used to create a new ApiCache instance (by default, simply requiring this library shares a common instance)apicache.clone()
- used to create a new ApiCache instance with the same options as the current one
Available Options (first value is default)
{
debug: false|true,
defaultDuration: '1 hour',
enabled: true|false,
redisClient: client,
appendKey: fn(req, res),
headerBlacklist: [],
statusCodes: {
exclude: [],
include: [],
},
trackPerformance: false,
headers: {
}
}
*Optional: Typescript Types (courtesy of @danielsogl)
$ npm install -D @types/apicache
Custom Cache Keys
Sometimes you need custom keys (e.g. save routes per-session, or per method).
We've made it easy!
Note: All req/res attributes used in the generation of the key must have been set
previously (upstream). The entire route logic block is skipped on future cache hits
so it can't rely on those params.
apicache.options({
appendKey: (req, res) => req.method + res.session.id,
})
Cache Key Groups
Oftentimes it benefits us to group cache entries, for example, by collection (in an API). This
would enable us to clear all cached "post" requests if we updated something in the "post" collection
for instance. Adding a simple req.apicacheGroup = [somevalue];
to your route enables this. See example below:
var apicache = require('apicache')
var cache = apicache.middleware
app.get('/api/:collection/:id?', cache('1 hour'), function(req, res, next) {
req.apicacheGroup = req.params.collection
res.send({ foo: 'bar' })
})
app.post('/api/:collection/:id?', function(req, res, next) {
apicache.clear(req.params.collection)
res.send('added a new item, so the cache has been cleared')
})
Additionally, you could add manual cache control to the previous project with routes such as these:
app.get('/api/cache/index', function(req, res, next) {
res.send(apicache.getIndex())
})
app.get('/api/cache/clear/:key?', function(req, res, next) {
res.send(200, apicache.clear(req.params.key || req.query.key))
})
Debugging/Console Out
Using Node environment variables (plays nicely with the hugely popular debug module)
$ export DEBUG=apicache
$ export DEBUG=apicache,othermoduleThatDebugModuleWillPickUp,etc
By setting internal option
import apicache from 'apicache'
apicache.options({ debug: true })
Client-Side Bypass
When sharing GET
routes between admin and public sites, you'll likely want the
routes to be cached from your public client, but NOT cached when from the admin client. This
is achieved by sending a "x-apicache-bypass": true
header along with the requst from the admin.
The presence of this header flag will bypass the cache, ensuring you aren't looking at stale data.
Contributors
Special thanks to all those that use this library and report issues, but especially to the following active users that have helped add to the core functionality!
- @killdash9 - restify support, performance/stats system, and too much else at this point to list
- @svozza - added restify tests, test suite refactor, and fixed header issue with restify. Node v7 + Restify v5 conflict resolution, etag/if-none-match support, etcetc, etc. Triple thanks!!!
- @andredigenova - Added header blacklist as options, correction to caching checks
- @peteboere - Node v7 headers update
- @rutgernation - JSONP support
- @enricsangra - added x-apicache-force-fetch header
- @tskillian - custom appendKey path support
- @agolden - Content-Encoding preservation (for gzip, etc)
- @davidyang - express 4+ compatibility
- @nmors - redis support
- @maytis, @ashwinnaidu - redis expiration
- @ubergesundheit - Corrected buffer accumulation using res.write with Buffers
- @danielsogl - Keeping dev deps up to date, Typescript Types
- @vectart - Added middleware local options support
- @davebaol - Added string support to defaultDuration option (previously just numeric ms)
- @Rauttis - Added ioredis support
- @fernandolguevara - Added opt-out for performance tracking, great emergency fix, thank you!!
Bugfixes, tweaks, documentation, etc.
- @Amhri, @Webcascade, @conmarap, @cjfurelid, @scambier, @lukechilds, @Red-Lv, @gesposito, @viebel, @RowanMeara, @GoingFast, @luin, @keithws, @daveross, @apascal, @guybrush
Changelog
- v1.5.3 - multiple fixes: Redis should be connected before using (thanks @guybrush)
- v1.5.2 - multiple fixes: Buffer deprecation and _headers deprecation, { trackPerformance: false } by default per discussion (sorry semver...)
- v1.5.1 - adds { trackPerformance } option to enable/disable performance tracking (thanks @fernandolguevara)
- v1.5.0 - exposes apicache.getPerformance() for per-route cache metrics (@killdash9 continues to deliver)
- v1.4.0 - cache-control header now auto-decrements in cached responses (thanks again, @killdash9)
- v1.3.0 - [securityfix] apicache headers no longer embedded in cached responses when NODE_ENV === 'production' (thanks for feedback @satya-jugran, @smddzcy, @adamelliotfields). Updated deps, now requiring Node v6.00+.
- v1.2.6 - middlewareToggle() now prevents response block on cache hit + falsy toggle (thanks @apascal)
- v1.2.5 - uses native Node setHeader() rather than express.js header() (thanks @keithws and @daveross)
- v1.2.4 - force content type to Buffer, using old and new Buffer creation syntax
- v1.2.3 - add etag to if-none-match 304 support (thanks for the test/issue @svozza)
- v1.2.2 - bugfix: ioredis.expire params (thanks @GoingFast and @luin)
- v1.2.1 - Updated deps
- v1.2.0 - Supports ioredis (thanks @Rauttis)
- v1.1.1 - bugfixes in expiration timeout clearing and content header preservation under compression (thanks @RowanMeara and @samimakicc).
- v1.1.0 - added the much-requested feature of a custom appendKey function (previously only took a path to a single request attribute). Now takes (request, response) objects and returns some value to be appended to the cache key.
- v1.0.0 - stamping v0.11.2 into official production version, will now begin developing on branch v2.x (redesign)
- v0.11.2 - dev-deps update, courtesy of @danielsogl
- v0.11.1 - correction to status code caching, and max-age headers are no longer sent when not cached. middlewareToggle now works as intended with example of statusCode checking (checks during shouldCacheResponse cycle)
- v0.11.0 - Added string support to defaultDuration option, previously just numeric ms - thanks @davebaol
- v0.10.0 - added ability to blacklist headers (prevents caching) via options.headersBlacklist (thanks @andredigenova)
- v0.9.1 - added eslint in prep for v1.x branch, minor ES6 to ES5 in master branch tests
- v0.9.0 - corrected Node v7.7 & v8 conflicts with restify (huge thanks to @svozza
for chasing this down and fixing upstream in restify itself). Added coveralls. Added
middleware.localOptions support (thanks @vectart). Added ability to overwrite/embed headers
(e.g. "cache-control": "no-cache") through options.
- v0.8.8 - corrected to use node v7+ headers (thanks @peteboere)
- v0.8.6, v0.8.7 - README update
- v0.8.5 - dev dependencies update (thanks @danielsogl)
- v0.8.4 - corrected buffer accumulation, with test support (thanks @ubergesundheit)
- v0.8.3 - added tests for x-apicache-bypass and x-apicache-force-fetch (legacy) and fixed a bug in the latter (thanks @Red-Lv)
- v0.8.2 - test suite and mock API refactor (thanks @svozza)
- v0.8.1 - fixed restify support and added appropriate tests (thanks @svozza)
- v0.8.0 - modifies response accumulation (thanks @killdash9) to support res.write + res.end accumulation, allowing integration with restify. Adds gzip support (Node v4.3.2+ now required) and tests.
- v0.7.0 - internally sets cache-control/max-age headers of response object
- v0.6.0 - removed final dependency (debug) and updated README
- v0.5.0 - updated internals to use res.end instead of res.send/res.json/res.jsonp, allowing for any response type, adds redis tests
- v0.4.0 - dropped lodash and memory-cache external dependencies, and bumped node version requirements to 4.0.0+ to allow Object.assign native support