Commit 730f3e33 authored by Michał Woźniak's avatar Michał Woźniak
Browse files

ipns-ipfs plugin in the works (ref. #2)

parent 8b63e69d
/**
* this is the default IPNS+IPFS strategy plugin
* for Samizdat.
*
* it uses IPNS for content address resolution
* and IPFS for delivery
*/
/*
* THIS PLUGIN IS WORK IN PROGRESS AND IS NOT FUNCTIONAL YET
*
* see: https://0xacab.org/rysiek/samizdat/-/issues/2
*/
/* ========================================================================= *\
|* === General stuff and setup === *|
\* ========================================================================= */
var ipfs;
// the pubkey of the preconfigured IPNS node
const ipnsPubKey = 'QmYGVgGGfD5N4Xcc78CcMJ99dKcH6K6myhd4Uenv5yJwiJ'
// the IPFS gateway we're using for verification
const IPFSGateway = 'https://gateway.ipfs.io'
/**
* importing stuff works differently between a browser window context
* and a ServiceWorker context, because things just can't be easy and sane
*/
function doImport() {
var args = Array.prototype.slice.call(arguments);
if (typeof self.importScripts !== 'undefined') {
self.importScripts.apply(self, args)
} else {
console.log('(COMMIT_UNKNOWN) assuming these scripts are already included:')
args.forEach(function(src){
console.log('+--', src)
})
}
}
async function setup_ipfs() {
if (ipfs === undefined) {
ipfs = false // we don't want to start a few times over
console.log('(COMMIT_UNKNOWN) Importing IPFS-related libraries...');
doImport(
"./lib/ipfs.js");
console.log('(COMMIT_UNKNOWN) Setting up IPFS...')
ipfs = await self.Ipfs.create({
config: {
dht: {
enabled: true,
clientMode: true
}
},
libp2p: {
config: {
dht: {
enabled: true,
clientMode: true
}
}
}
});
console.log('+-- IPFS loaded :: ipfs is : ' + typeof ipfs)
}
}
/* ========================================================================= *\
|* === Main functionality === *|
\* ========================================================================= */
/**
* the workhorse of this plugin
*/
async function getContentFromIPNSAndIPFS(url) {
var urlArray = url.replace(/https?:\/\//, '').split('/')
var gunaddr = [urlArray[0], '/' + urlArray.slice(1).join('/')]
/*
* if the gunaddr[1] ends in '/', append 'index.html' to it
*/
if (gunaddr[1].charAt(gunaddr[1].length - 1) === '/') {
console.log("NOTICE: address ends in '/', assuming '/index.html' should be appended.");
gunaddr[1] += 'index.html';
}
console.log("2. Starting Gun lookup of: '" + gunaddr.join(', ') + "'");
console.log(" +-- gun : " + typeof gun);
console.log(" +-- gunUser : " + typeof gunUser);
/*
* naïvely assume content type based on file extension
* TODO: this needs a fix
*/
var contentType = '';
switch (gunaddr.slice(-1)[0].split('.', -1)[1].toLowerCase()) {
case 'html':
case 'htm':
contentType = 'text/html';
break;
case 'css':
contentType = 'text/css';
break;
case 'js':
contentType = 'text/javascript';
break;
case 'svg':
contentType = 'image/svg+xml';
break;
case 'ico':
contentType = 'image/x-icon';
break;
}
console.log(" +-- guessed contentType : " + contentType);
return getGunData(gunaddr).then(ipfsaddr => {
console.log("3. Starting IPFS lookup of: '" + ipfsaddr + "'");
return ipfs.get(ipfsaddr).next();
}).then(file => {
// we only need one
if (file.value.content) {
async function getContent(source) {
var content = new Uint8Array()
var data = await source.next()
while (! data.done) {
var newContent = new Uint8Array(content.length + data.value.length);
newContent.set(content)
newContent.set(data.value, content.length)
content = newContent
data = await source.next()
}
return content
}
return getContent(file.value.content).then((content)=>{
console.log('4. Got a Gun-addressed IPFS-stored file: ' + file.value.path + '; content is: ' + typeof content);
// creating and populating the blob
var blob = new Blob(
[content],
{'type': contentType}
);
return new Response(
blob,
{
'status': 200,
'statusText': 'OK',
'headers': {
'Content-Type': contentType,
'ETag': file.value.path,
'X-Samizdat-Method': 'gun+ipfs',
'X-Samizdat-ETag': file.value.path
}
}
);
})
};
});
}
/* ========================================================================= *\
|* === Publishing stuff === *|
\* ========================================================================= */
/*
* these are used for adding content to IPFS and Gun
*/
/**
* adding stuff to IPFS
* accepts an array of URLs
*
* returns a Promise that resolves to an object mapping URLs to IPFS hashes
*/
let addToIPFS = (resources) => {
return new Promise((resolve, reject) => {
console.log("Adding to IPFS...")
console.log("+-- number of resources:", resources.length)
var ipfs_addresses = {};
resources.forEach(function(res){
console.log(" +-- handling internal resource:", res)
ipfs.add(Ipfs.urlSource(res))
.then((result) => {
// add to the list -- this is needed to add stuff to Gun
// result.path is just the filename stored in IPFS, not the actual path!
// res holds the full URL
// what we need in ipfs_addresses is in fact the absolute path (no domain, no scheme)
var abs_path = res.replace(window.location.origin, '')
ipfs_addresses[abs_path] = '/ipfs/' + result.cid.string
console.log("Added to IPFS: " + abs_path + ' as ' + ipfs_addresses[abs_path])
// if we seem to have all we need, resolve!
if (Object.keys(ipfs_addresses).length === resources.length) resolve(ipfs_addresses);
})
});
})
}
/**
* verification that content pushed to IPFS
* is, in fact, available in IPFS
*
* a nice side-effect is that this will pre-load the content on
* a gateway, which tends to be a large (and fast) IPFS node
*
* this is prety naïve, in that it pulls the content from an ipfs gateway
* and assumes all is well if it get a HTTP 200 and any content
*
* that is, it does *not* check that the content matches what was pushed
* we trust IPFS here, I guess
*
* finally, we're using a regular fetch() instead of just going through our
* ipfs object because our IPFS object might have things cached and we want
* to test a completey independent route
*
* takes a object mapping paths to IPFS addresses
* and returns a Promise that resolves to true
*/
let verifyInIPFS = (ipfs_addresses) => {
return new Promise((resolve, reject) => {
console.log('Checking IPFS content against a gateway...')
console.log('+-- gateway in use: ' + IPFSGateway)
// get the list of IPFS addresses
var updatedPaths = Object.values(ipfs_addresses)
for (path in ipfs_addresses) {
// start the fetch
fetch(IPFSGateway + ipfs_addresses[path])
.then((response) => {
ipfsaddr = response.url.replace(IPFSGateway, '')
if (response.ok) {
console.log('+-- verified: ' + ipfsaddr)
var pathIndex = updatedPaths.indexOf(ipfsaddr)
if (pathIndex > -1) {
updatedPaths.splice(pathIndex, 1)
}
if (updatedPaths.length === 0) {
console.log('All updates confirmed successful!')
resolve(ipfs_addresses);
}
} else {
reject(new Error('HTTP error (' + response.status + ' ' + response.statusText + ' for: ' + ipfsaddr))
}
})
.catch((err) => {
// it would be nice to have the failed path here somehow
// alternatively, updating updatedPaths with info on failed
// requests might work
reject(err)
})
}
})
}
/**
* example code for of adding content to IPFS, verifying it was successfully added,
* and adding the new addresses to Gun (and verifying changes propagated)
*
* TODO: this should accept a URL, a Response, or a list of URLs,
* and handle stuff appropriately
*/
let publishContent = (resource, user, password) => {
if (typeof resource === 'string') {
// we need this as an array of strings
resource = [resource]
} else if (typeof resource === 'object') {
if (!Array.isArray(resource)) {
// TODO: this needs to be implemented such that the Response is used directly
// but that would require all called functions to also accept a Response
// and act accordingly; #ThisIsComplicated
throw new Error("Handling a Response: not implemented yet")
}
} else {
// everything else -- that's a paddlin'!
throw new TypeError("Only accepts: string, Array of string, Response.")
}
// add to IPFS
var ipfsPromise = addToIPFS(resource)
return Promise.all([
// verify stuff ended up in IPFS
ipfsPromise.then(verifyInIPFS),
// add to Gun and verify Gun updates propagation
ipfsPromise.then((hashes) => {
addToGun(user, password, hashes)
})
])
}
/* ========================================================================= *\
|* === Initialization === *|
\* ========================================================================= */
// we probably need to handle this better
setup_ipfs();
// initialize the SamizdatPlugins array
if (!Array.isArray(self.SamizdatPlugins)) {
self.SamizdatPlugins = new Array()
}
// and add ourselves to it
// with some additional metadata
self.SamizdatPlugins.push({
name: 'ipns+ipfs',
description: 'Decentralized resource fetching using IPNS for address resolution and IPFS for content delivery.',
version: 'COMMIT_UNKNOWN',
fetch: getContentFromIPNSAndIPFS,
publish: publishContent
})
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