fix(server): 🩹 Using sessionID as a fallback to requests where refere…

…r is missing.

Signed-off-by: Nishant Arora <[email protected]>

package.json

@@ -38,6 +38,7 @@
   "homepage": "https://github.com/whizzzkid/helia-docker#readme",
   "devDependencies": {
     "@types/express": "4.x",
+    "@types/express-session": "1.17.9",
     "@types/mime-types": "2.x",
     "@types/node": "20.x",
     "aegir": "40.x",
@@ -48,6 +49,7 @@
     "@helia/unixfs": "1.x",
     "express": "4.x",
     "express-prom-bundle": "6.x",
+    "express-session": "1.17.3",
     "file-type": "18.x",
     "helia": "2.x",
     "lru-cache": "10.x",

src/heliaServer.ts

@@ -59,23 +59,36 @@ export class HeliaServer {
     ]
   }
 
+  /**
+   * Computes referer path for the request.
+   */
+  private fetchRefererPath ({ request }: IRouteHandler): string {
+    let refererPath = new URL(request.headers.referer ?? 'http://ipfs.io').pathname
+    if (refererPath === '/') {
+      refererPath = request.sessionID
+    }
+
+    if (refererPath !== undefined) {
+      return refererPath
+    }
+
+    throw new Error('Error calculating referer')
+  }
+
   /**
    * Handles redirecting to the relative path
    */
   private async redirectRelative ({ request, response }: IRouteHandler): Promise<void> {
     try {
-      const referrerPath = new URL(request.headers.referer ?? '').pathname
-      if (referrerPath !== undefined) {
-        this.log('Referer found:', referrerPath)
-        let relativeRedirectPath = `${referrerPath}${request.path}`
-        const { namespace, address } = this.heliaFetch.parsePath(referrerPath)
-        if (namespace === 'ipns') {
-          relativeRedirectPath = `/${namespace}/${address}${request.path}`
-        }
-        // absolute redirect
-        this.log('Redirecting to relative to referer:', referrerPath)
-        response.redirect(relativeRedirectPath)
+      const refererPath = this.fetchRefererPath({ request, response })
+      let relativeRedirectPath = `${refererPath}${request.path}`
+      const { namespace, address } = this.heliaFetch.parsePath(refererPath)
+      if (namespace === 'ipns') {
+        relativeRedirectPath = `/${namespace}/${address}${request.path}`
       }
+      // absolute redirect
+      this.log('Redirecting to relative to referer:', refererPath)
+      response.redirect(relativeRedirectPath)
     } catch (error) {
       this.log('Error redirecting to relative path:', error)
       response.status(500).end()
@@ -113,9 +126,8 @@ export class HeliaServer {
       address: reqDomain
     } = this.heliaFetch.parsePath(request.path)
 
-    if (request.headers.referer !== undefined) {
-      this.log('Referer found:', request.headers.referer)
-      const refererPath = new URL(request.headers.referer).pathname
+    try {
+      const refererPath = this.fetchRefererPath({ request, response })
       const {
         namespace: refNamespace,
         address: refDomain
@@ -131,6 +143,8 @@ export class HeliaServer {
           return true
         }
       }
+    } catch (error) {
+      this.log('Error checking for additional redirection:', error)
     }
     return false
   }
@@ -190,4 +204,14 @@ export class HeliaServer {
     await this.heliaFetch.node?.gc()
     response.status(200).end()
   }
+
+  /**
+   * Generates a session ID for the request.
+   * This is a very ghetto way of identifying what the root ipns path for a request is.
+   * Overloading the sessionID the first request allows us to use the same session for all subsequent requests. Mostly!
+   * In many cases it won't work, but the browser won't care for those either.
+   */
+  public sessionId (request: Request): string {
+    return request.sessionID ?? request.path
+  }
 }

src/index.ts

@@ -1,21 +1,26 @@
 import debug from 'debug'
 import express from 'express'
 import promBundle from 'express-prom-bundle'
+import session from 'express-session'
 import { HeliaServer, type IRouteEntry } from './heliaServer.js'
 
 const logger = debug('helia-server')
-const app = express()
 const promMetricsMiddleware = promBundle({ includeMethod: true })
 
+const heliaServer = new HeliaServer(logger)
+await heliaServer.isReady
+
 // Constants
 const PORT = (process?.env?.PORT ?? 8080) as number
 const HOST = process?.env?.HOST ?? '0.0.0.0'
 
 // Add the prometheus middleware
+const app = express()
 app.use(promMetricsMiddleware)
-
-const heliaServer = new HeliaServer(logger)
-await heliaServer.isReady
+app.use(session({
+  genid: heliaServer.sessionId,
+  secret: 'very secret value'
+}))
 
 // Add the routes
 app.get('/', (req, res) => {