Merge pull request #719 from solid/group-acl-integration

Merging the code for Group ACL integration, as they are. There are some known fragilities, but we should have this functionality to support experimentation at this point.

Author: kjetilk

.travis.yml

@@ -1,7 +1,7 @@
 sudo: false
 language: node_js
 node_js:
-  - "8.10"
+  - "8.0"
   - "10.0"
   - "node"
 env:
@@ -18,6 +18,9 @@ addons:
     - tim.localhost
     - nicola.localhost
 
+before_install:
+  - npm install -g npm@latest
+
 script:
   - npm run standard
   - npm run sonar

lib/acl-checker.js

@@ -14,6 +14,7 @@ class ACLChecker {
     this.host = options.host
     this.origin = options.origin
     this.fetch = options.fetch
+    this.fetchGraph = options.fetchGraph
     this.strictOrigin = options.strictOrigin
     this.suffix = options.suffix || DEFAULT_ACL_SUFFIX
   }
@@ -87,7 +88,8 @@ class ACLChecker {
 
   // Tests whether the permissions allow a given operation
   checkAccess (permissionSet, user, mode) {
-    return permissionSet.checkAccess(this.resource, user, mode)
+    const options = { fetchGraph: this.fetchGraph }
+    return permissionSet.checkAccess(this.resource, user, mode, options)
       .then(hasAccess => {
         if (hasAccess) {
           return true

lib/handlers/allow.js

@@ -39,6 +39,12 @@ function allow (mode) {
         origin: req.get('origin'),
         host: req.protocol + '://' + req.get('host'),
         fetch: fetchFromLdp(mapper, ldp),
+        fetchGraph: (uri, options) => {
+          // first try loading from local fs
+          return ldp.getGraph(uri, options.contentType)
+            // failing that, fetch remote graph
+            .catch(() => ldp.fetchGraph(uri, options))
+        },
         suffix: ldp.suffixAcl,
         strictOrigin: ldp.strictOrigin
       })

lib/ldp.js

@@ -14,6 +14,8 @@ const extend = require('extend')
 const rimraf = require('rimraf')
 const ldpContainer = require('./ldp-container')
 const parse = require('./utils').parse
+const fetch = require('node-fetch')
+const { promisify } = require('util')
 
 const DEFAULT_CONTENT_TYPE = 'text/turtle'
 
@@ -296,7 +298,40 @@ class LDP {
   }
 
   /**
-   * Fetches the graph at a given uri, parses it and and returns it.
+   * Remotely loads the graph at a given uri, parses it and and returns it.
+   * Usage:
+   *
+   *   ```
+   *   ldp.fetchGraph('https://example.com/contacts/card1.ttl')
+   *     .then(graph => {
+   *       // const matches = graph.match(...)
+   *     })
+   *   ```
+   *
+   * @param uri {string} Fully qualified uri of the request.
+   *
+   * @param [options] {object} Options hashmap, passed through to fetchGraph
+   *
+   * @return {Promise<Graph>}
+   */
+  async fetchGraph (uri, options) {
+    const response = await fetch(uri)
+    if (!response.ok) {
+      const error = new Error(
+        `Error fetching ${uri}: ${response.status} ${response.statusText}`
+      )
+      error.statusCode = response.status || 400
+      throw error
+    }
+    const body = await response.text()
+
+    const contentType = options.contentType || DEFAULT_CONTENT_TYPE
+
+    return promisify(parse)(body, uri, contentType)
+  }
+
+  /**
+   * Loads from fs the graph at a given uri, parses it and and returns it.
    * Usage:
    *
    *   ```