396 lines
16 KiB
Markdown
396 lines
16 KiB
Markdown
# make-fetch-happen
|
||
[](https://npm.im/make-fetch-happen) [](https://npm.im/make-fetch-happen) [](https://travis-ci.org/npm/make-fetch-happen) [](https://coveralls.io/github/npm/make-fetch-happen?branch=latest)
|
||
|
||
[`make-fetch-happen`](https://github.com/npm/make-fetch-happen) is a Node.js
|
||
library that wraps [`minipass-fetch`](https://github.com/npm/minipass-fetch) with additional
|
||
features [`minipass-fetch`](https://github.com/npm/minipass-fetch) doesn't intend to include, including HTTP Cache support, request
|
||
pooling, proxies, retries, [and more](#features)!
|
||
|
||
## Install
|
||
|
||
`$ npm install --save make-fetch-happen`
|
||
|
||
## Table of Contents
|
||
|
||
* [Example](#example)
|
||
* [Features](#features)
|
||
* [Contributing](#contributing)
|
||
* [API](#api)
|
||
* [`fetch`](#fetch)
|
||
* [`fetch.defaults`](#fetch-defaults)
|
||
* [`minipass-fetch` options](#minipass-fetch-options)
|
||
* [`make-fetch-happen` options](#extra-options)
|
||
* [`opts.cachePath`](#opts-cache-path)
|
||
* [`opts.cache`](#opts-cache)
|
||
* [`opts.proxy`](#opts-proxy)
|
||
* [`opts.noProxy`](#opts-no-proxy)
|
||
* [`opts.ca, opts.cert, opts.key`](#https-opts)
|
||
* [`opts.maxSockets`](#opts-max-sockets)
|
||
* [`opts.retry`](#opts-retry)
|
||
* [`opts.onRetry`](#opts-onretry)
|
||
* [`opts.integrity`](#opts-integrity)
|
||
* [Message From Our Sponsors](#wow)
|
||
|
||
### Example
|
||
|
||
```javascript
|
||
const fetch = require('make-fetch-happen').defaults({
|
||
cachePath: './my-cache' // path where cache will be written (and read)
|
||
})
|
||
|
||
fetch('https://registry.npmjs.org/make-fetch-happen').then(res => {
|
||
return res.json() // download the body as JSON
|
||
}).then(body => {
|
||
console.log(`got ${body.name} from web`)
|
||
return fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
cache: 'no-cache' // forces a conditional request
|
||
})
|
||
}).then(res => {
|
||
console.log(res.status) // 304! cache validated!
|
||
return res.json().then(body => {
|
||
console.log(`got ${body.name} from cache`)
|
||
})
|
||
})
|
||
```
|
||
|
||
### Features
|
||
|
||
* Builds around [`minipass-fetch`](https://npm.im/minipass-fetch) for the core [`fetch` API](https://fetch.spec.whatwg.org) implementation
|
||
* Request pooling out of the box
|
||
* Quite fast, really
|
||
* Automatic HTTP-semantics-aware request retries
|
||
* Cache-fallback automatic "offline mode"
|
||
* Proxy support (http, https, socks, socks4, socks5)
|
||
* Built-in request caching following full HTTP caching rules (`Cache-Control`, `ETag`, `304`s, cache fallback on error, etc).
|
||
* Customize cache storage with any [Cache API](https://developer.mozilla.org/en-US/docs/Web/API/Cache)-compliant `Cache` instance. Cache to Redis!
|
||
* Node.js Stream support
|
||
* Transparent gzip and deflate support
|
||
* [Subresource Integrity](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) support
|
||
* Literally punches nazis
|
||
* (PENDING) Range request caching and resuming
|
||
|
||
### Contributing
|
||
|
||
The make-fetch-happen team enthusiastically welcomes contributions and project participation! There's a bunch of things you can do if you want to contribute! The [Contributor Guide](https://github.com/npm/cli/blob/latest/CONTRIBUTING.md) outlines the process for community interaction and contribution. Please don't hesitate to jump in if you'd like to, or even ask us questions if something isn't clear.
|
||
|
||
All participants and maintainers in this project are expected to follow the [npm Code of Conduct](https://www.npmjs.com/policies/conduct), and just generally be excellent to each other.
|
||
|
||
Please refer to the [Changelog](CHANGELOG.md) for project history details, too.
|
||
|
||
Happy hacking!
|
||
|
||
### API
|
||
|
||
#### <a name="fetch"></a> `> fetch(uriOrRequest, [opts]) -> Promise<Response>`
|
||
|
||
This function implements most of the [`fetch` API](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch): given a `uri` string or a `Request` instance, it will fire off an http request and return a Promise containing the relevant response.
|
||
|
||
If `opts` is provided, the [`minipass-fetch`-specific options](#minipass-fetch-options) will be passed to that library. There are also [additional options](#extra-options) specific to make-fetch-happen that add various features, such as HTTP caching, integrity verification, proxy support, and more.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://google.com').then(res => res.buffer())
|
||
```
|
||
|
||
#### <a name="fetch-defaults"></a> `> fetch.defaults([defaultUrl], [defaultOpts])`
|
||
|
||
Returns a new `fetch` function that will call `make-fetch-happen` using `defaultUrl` and `defaultOpts` as default values to any calls.
|
||
|
||
A defaulted `fetch` will also have a `.defaults()` method, so they can be chained.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
const fetch = require('make-fetch-happen').defaults({
|
||
cachePath: './my-local-cache'
|
||
})
|
||
|
||
fetch('https://registry.npmjs.org/make-fetch-happen') // will always use the cache
|
||
```
|
||
|
||
#### <a name="minipass-fetch-options"></a> `> minipass-fetch options`
|
||
|
||
The following options for `minipass-fetch` are used as-is:
|
||
|
||
* method
|
||
* body
|
||
* redirect
|
||
* follow
|
||
* timeout
|
||
* compress
|
||
* size
|
||
|
||
These other options are modified or augmented by make-fetch-happen:
|
||
|
||
* headers - Default `User-Agent` set to make-fetch happen. `Connection` is set to `keep-alive` or `close` automatically depending on `opts.agent`.
|
||
* agent
|
||
* If agent is null, an http or https Agent will be automatically used. By default, these will be `http.globalAgent` and `https.globalAgent`.
|
||
* If [`opts.proxy`](#opts-proxy) is provided and `opts.agent` is null, the agent will be set to an appropriate proxy-handling agent.
|
||
* If `opts.agent` is an object, it will be used as the request-pooling agent argument for this request.
|
||
* If `opts.agent` is `false`, it will be passed as-is to the underlying request library. This causes a new Agent to be spawned for every request.
|
||
|
||
For more details, see [the documentation for `minipass-fetch` itself](https://github.com/npm/minipass-fetch#options).
|
||
|
||
#### <a name="extra-options"></a> `> make-fetch-happen options`
|
||
|
||
make-fetch-happen augments the `minipass-fetch` API with additional features available through extra options. The following extra options are available:
|
||
|
||
* [`opts.cachePath`](#opts-cache-path) - Cache target to read/write
|
||
* [`opts.cache`](#opts-cache) - `fetch` cache mode. Controls cache *behavior*.
|
||
* [`opts.proxy`](#opts-proxy) - Proxy agent
|
||
* [`opts.noProxy`](#opts-no-proxy) - Domain segments to disable proxying for.
|
||
* [`opts.ca, opts.cert, opts.key, opts.strictSSL`](#https-opts)
|
||
* [`opts.localAddress`](#opts-local-address)
|
||
* [`opts.maxSockets`](#opts-max-sockets)
|
||
* [`opts.retry`](#opts-retry) - Request retry settings
|
||
* [`opts.onRetry`](#opts-onretry) - a function called whenever a retry is attempted
|
||
* [`opts.integrity`](#opts-integrity) - [Subresource Integrity](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) metadata.
|
||
|
||
#### <a name="opts-cache-path"></a> `> opts.cachePath`
|
||
|
||
A string `Path` to be used as the cache root for [`cacache`](https://npm.im/cacache).
|
||
|
||
**NOTE**: Requests will not be cached unless their response bodies are consumed. You will need to use one of the `res.json()`, `res.buffer()`, etc methods on the response, or drain the `res.body` stream, in order for it to be written.
|
||
|
||
The default cache manager also adds the following headers to cached responses:
|
||
|
||
* `X-Local-Cache`: Path to the cache the content was found in
|
||
* `X-Local-Cache-Key`: Unique cache entry key for this response
|
||
* `X-Local-Cache-Mode`: Either `stream` or `buffer` to indicate how the response was read from cacache
|
||
* `X-Local-Cache-Hash`: Specific integrity hash for the cached entry
|
||
* `X-Local-Cache-Status`: One of `miss`, `hit`, `stale`, `revalidated`, `updated`, or `skip` to signal how the response was created
|
||
* `X-Local-Cache-Time`: UTCString of the cache insertion time for the entry
|
||
|
||
Using [`cacache`](https://npm.im/cacache), a call like this may be used to
|
||
manually fetch the cached entry:
|
||
|
||
```javascript
|
||
const h = response.headers
|
||
cacache.get(h.get('x-local-cache'), h.get('x-local-cache-key'))
|
||
|
||
// grab content only, directly:
|
||
cacache.get.byDigest(h.get('x-local-cache'), h.get('x-local-cache-hash'))
|
||
```
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
cachePath: './my-local-cache'
|
||
}) // -> 200-level response will be written to disk
|
||
```
|
||
|
||
A possible (minimal) implementation for `MyCustomRedisCache`:
|
||
|
||
```javascript
|
||
const bluebird = require('bluebird')
|
||
const redis = require("redis")
|
||
bluebird.promisifyAll(redis.RedisClient.prototype)
|
||
class MyCustomRedisCache {
|
||
constructor (opts) {
|
||
this.redis = redis.createClient(opts)
|
||
}
|
||
match (req) {
|
||
return this.redis.getAsync(req.url).then(res => {
|
||
if (res) {
|
||
const parsed = JSON.parse(res)
|
||
return new fetch.Response(parsed.body, {
|
||
url: req.url,
|
||
headers: parsed.headers,
|
||
status: 200
|
||
})
|
||
}
|
||
})
|
||
}
|
||
put (req, res) {
|
||
return res.buffer().then(body => {
|
||
return this.redis.setAsync(req.url, JSON.stringify({
|
||
body: body,
|
||
headers: res.headers.raw()
|
||
}))
|
||
}).then(() => {
|
||
// return the response itself
|
||
return res
|
||
})
|
||
}
|
||
'delete' (req) {
|
||
return this.redis.unlinkAsync(req.url)
|
||
}
|
||
}
|
||
```
|
||
|
||
#### <a name="opts-cache"></a> `> opts.cache`
|
||
|
||
This option follows the standard `fetch` API cache option. This option will do nothing if [`opts.cachePath`](#opts-cache-path) is null. The following values are accepted (as strings):
|
||
|
||
* `default` - Fetch will inspect the HTTP cache on the way to the network. If there is a fresh response it will be used. If there is a stale response a conditional request will be created, and a normal request otherwise. It then updates the HTTP cache with the response. If the revalidation request fails (for example, on a 500 or if you're offline), the stale response will be returned.
|
||
* `no-store` - Fetch behaves as if there is no HTTP cache at all.
|
||
* `reload` - Fetch behaves as if there is no HTTP cache on the way to the network. Ergo, it creates a normal request and updates the HTTP cache with the response.
|
||
* `no-cache` - Fetch creates a conditional request if there is a response in the HTTP cache and a normal request otherwise. It then updates the HTTP cache with the response.
|
||
* `force-cache` - Fetch uses any response in the HTTP cache matching the request, not paying attention to staleness. If there was no response, it creates a normal request and updates the HTTP cache with the response.
|
||
* `only-if-cached` - Fetch uses any response in the HTTP cache matching the request, not paying attention to staleness. If there was no response, it returns a network error. (Can only be used when request’s mode is "same-origin". Any cached redirects will be followed assuming request’s redirect mode is "follow" and the redirects do not violate request’s mode.)
|
||
|
||
(Note: option descriptions are taken from https://fetch.spec.whatwg.org/#http-network-or-cache-fetch)
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
const fetch = require('make-fetch-happen').defaults({
|
||
cachePath: './my-cache'
|
||
})
|
||
|
||
// Will error with ENOTCACHED if we haven't already cached this url
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
cache: 'only-if-cached'
|
||
})
|
||
|
||
// Will refresh any local content and cache the new response
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
cache: 'reload'
|
||
})
|
||
|
||
// Will use any local data, even if stale. Otherwise, will hit network.
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
cache: 'force-cache'
|
||
})
|
||
```
|
||
|
||
#### <a name="opts-proxy"></a> `> opts.proxy`
|
||
|
||
A string or `new url.URL()`-d URI to proxy through. Different Proxy handlers will be
|
||
used depending on the proxy's protocol.
|
||
|
||
Additionally, `process.env.HTTP_PROXY`, `process.env.HTTPS_PROXY`, and
|
||
`process.env.PROXY` are used if present and no `opts.proxy` value is provided.
|
||
|
||
(Pending) `process.env.NO_PROXY` may also be configured to skip proxying requests for all, or specific domains.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
proxy: 'https://corporate.yourcompany.proxy:4445'
|
||
})
|
||
|
||
fetch('https://registry.npmjs.org/make-fetch-happen', {
|
||
proxy: {
|
||
protocol: 'https:',
|
||
hostname: 'corporate.yourcompany.proxy',
|
||
port: 4445
|
||
}
|
||
})
|
||
```
|
||
|
||
#### <a name="opts-no-proxy"></a> `> opts.noProxy`
|
||
|
||
If present, should be a comma-separated string or an array of domain extensions
|
||
that a proxy should _not_ be used for.
|
||
|
||
This option may also be provided through `process.env.NO_PROXY`.
|
||
|
||
#### <a name="https-opts"></a> `> opts.ca, opts.cert, opts.key, opts.strictSSL`
|
||
|
||
These values are passed in directly to the HTTPS agent and will be used for both
|
||
proxied and unproxied outgoing HTTPS requests. They mostly correspond to the
|
||
same options the `https` module accepts, which will be themselves passed to
|
||
`tls.connect()`. `opts.strictSSL` corresponds to `rejectUnauthorized`.
|
||
|
||
#### <a name="opts-local-address"></a> `> opts.localAddress`
|
||
|
||
Passed directly to `http` and `https` request calls. Determines the local
|
||
address to bind to.
|
||
|
||
#### <a name="opts-max-sockets"></a> `> opts.maxSockets`
|
||
|
||
Default: 15
|
||
|
||
Maximum number of active concurrent sockets to use for the underlying
|
||
Http/Https/Proxy agents. This setting applies once per spawned agent.
|
||
|
||
15 is probably a _pretty good value_ for most use-cases, and balances speed
|
||
with, uh, not knocking out people's routers. 🤓
|
||
|
||
#### <a name="opts-retry"></a> `> opts.retry`
|
||
|
||
An object that can be used to tune request retry settings. Retries will only be attempted on the following conditions:
|
||
|
||
* Request method is NOT `POST` AND
|
||
* Request status is one of: `408`, `420`, `429`, or any status in the 500-range. OR
|
||
* Request errored with `ECONNRESET`, `ECONNREFUSED`, `EADDRINUSE`, `ETIMEDOUT`, or the `fetch` error `request-timeout`.
|
||
|
||
The following are worth noting as explicitly not retried:
|
||
|
||
* `getaddrinfo ENOTFOUND` and will be assumed to be either an unreachable domain or the user will be assumed offline. If a response is cached, it will be returned immediately.
|
||
|
||
If `opts.retry` is `false`, it is equivalent to `{retries: 0}`
|
||
|
||
If `opts.retry` is a number, it is equivalent to `{retries: num}`
|
||
|
||
The following retry options are available if you want more control over it:
|
||
|
||
* retries
|
||
* factor
|
||
* minTimeout
|
||
* maxTimeout
|
||
* randomize
|
||
|
||
For details on what each of these do, refer to the [`retry`](https://npm.im/retry) documentation.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://flaky.site.com', {
|
||
retry: {
|
||
retries: 10,
|
||
randomize: true
|
||
}
|
||
})
|
||
|
||
fetch('http://reliable.site.com', {
|
||
retry: false
|
||
})
|
||
|
||
fetch('http://one-more.site.com', {
|
||
retry: 3
|
||
})
|
||
```
|
||
|
||
#### <a name="opts-onretry"></a> `> opts.onRetry`
|
||
|
||
A function called whenever a retry is attempted.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://flaky.site.com', {
|
||
onRetry() {
|
||
console.log('we will retry!')
|
||
}
|
||
})
|
||
```
|
||
|
||
#### <a name="opts-integrity"></a> `> opts.integrity`
|
||
|
||
Matches the response body against the given [Subresource Integrity](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) metadata. If verification fails, the request will fail with an `EINTEGRITY` error.
|
||
|
||
`integrity` may either be a string or an [`ssri`](https://npm.im/ssri) `Integrity`-like.
|
||
|
||
##### Example
|
||
|
||
```javascript
|
||
fetch('https://registry.npmjs.org/make-fetch-happen/-/make-fetch-happen-1.0.0.tgz', {
|
||
integrity: 'sha1-o47j7zAYnedYFn1dF/fR9OV3z8Q='
|
||
}) // -> ok
|
||
|
||
fetch('https://malicious-registry.org/make-fetch-happen/-/make-fetch-happen-1.0.0.tgz', {
|
||
integrity: 'sha1-o47j7zAYnedYFn1dF/fR9OV3z8Q='
|
||
}) // Error: EINTEGRITY
|
||
```
|
||
|
||
### <a name="wow"></a> Message From Our Sponsors
|
||
|
||
|
||
|
||
|