Merge pull request jupyterhub#1847 from minrk/fetch-events

handle api tokens and xsrf

binderhub/app.py

@@ -962,8 +962,7 @@ def initialize(self, *args, **kwargs):
                 "enable_api_only_mode": self.enable_api_only_mode,
             }
         )
-        if self.auth_enabled:
-            self.tornado_settings["cookie_secret"] = os.urandom(32)
+        self.tornado_settings["cookie_secret"] = os.urandom(32)
         if self.cors_allow_origin:
             self.tornado_settings.setdefault("headers", {})[
                 "Access-Control-Allow-Origin"

binderhub/base.py

@@ -137,11 +137,20 @@ def get_current_user(self):
 
     @property
     def template_namespace(self):
-        return dict(
+
+        ns = dict(
             static_url=self.static_url,
             banner=self.settings["banner_message"],
-            **self.settings.get("template_variables", {}),
+            auth_enabled=self.settings["auth_enabled"],
+        )
+        if self.settings["auth_enabled"]:
+            ns["xsrf"] = self.xsrf_token.decode("ascii")
+            ns["api_token"] = self.hub_auth.get_token(self) or ""
+
+        ns.update(
+            self.settings.get("template_variables", {}),
         )
+        return ns
 
     def set_default_headers(self):
         headers = self.settings.get("headers", {})

binderhub/builder.py

@@ -247,6 +247,10 @@ def _get_build_only(self):
 
         return build_only
 
+    def redirect(self, *args, **kwargs):
+        # disable redirect to login, which won't work for EventSource
+        raise HTTPError(403)
+
     @authenticated
     async def get(self, provider_prefix, _unescaped_spec):
         """Get a built image for a given spec and repo provider.

binderhub/static/js/index.js

@@ -1,7 +1,6 @@
 /* If this file gets over 200 lines of code long (not counting docs / comments), start using a framework
  */
 import ClipboardJS from "clipboard";
-import "event-source-polyfill";
 
 import { BinderRepository } from "@jupyterhub/binderhub-client";
 import { updatePathText } from "./src/path";
@@ -61,12 +60,12 @@ async function build(providerSpec, log, fitAddon, path, pathType) {
   $(".on-build").removeClass("hidden");
 
   const buildToken = $("#build-token").data("token");
+  const apiToken = $("#api-token").data("token");
   const buildEndpointUrl = new URL("build", BASE_URL);
-  const image = new BinderRepository(
-    providerSpec,
-    buildEndpointUrl,
+  const image = new BinderRepository(providerSpec, buildEndpointUrl, {
+    apiToken,
     buildToken,
-  );
+  });
 
   for await (const data of image.fetch()) {
     // Write message to the log terminal if there is a message

binderhub/static/js/src/repo.js

@@ -24,8 +24,16 @@ function setLabels() {
  */
 export function updateRepoText(baseUrl) {
   if (Object.keys(configDict).length === 0) {
+    const xsrf = $("#xsrf-token").data("token");
+    const apiToken = $("#api-token").data("token");
     const configUrl = new URL("_config", baseUrl);
-    fetch(configUrl).then((resp) => {
+    const headers = {};
+    if (apiToken && apiToken.length > 0) {
+      headers["Authorization"] = `Bearer ${apiToken}`;
+    } else if (xsrf && xsrf.length > 0) {
+      headers["X-Xsrftoken"] = xsrf;
+    }
+    fetch(configUrl, { headers }).then((resp) => {
       resp.json().then((data) => {
         configDict = data;
         setLabels();

binderhub/templates/index.html

@@ -3,6 +3,8 @@
 {% block head %}
 <meta id="base-url" data-url="{{base_url}}">
 <meta id="badge-base-url" data-url="{{badge_base_url}}">
+<meta id="api-token" data-token="{{ api_token }}">
+<meta id="xsrf-token" data-token="{{ xsrf }}">
 <script src="{{static_url("dist/bundle.js")}}"></script>
 {{ super() }}
 {% endblock head %}

binderhub/templates/loading.html

@@ -14,6 +14,8 @@
 <meta id="base-url" data-url="{{base_url}}">
 <meta id="badge-base-url" data-url="{{badge_base_url}}">
 <meta id="build-token" data-token="{{ build_token }}">
+<meta id="api-token" data-token="{{ api_token }}">
+<meta id="xsrf-token" data-token="{{ xsrf }}">
 {{ super() }}
 <script src="{{static_url("dist/bundle.js")}}"></script>
 <link href="{{static_url("loading.css")}}" rel="stylesheet">

js/packages/binderhub-client/lib/index.js

@@ -1,8 +1,30 @@
-import { NativeEventSource, EventSourcePolyfill } from "event-source-polyfill";
+import { fetchEventSource } from "@microsoft/fetch-event-source";
 import { EventIterator } from "event-iterator";
 
-// Use native browser EventSource if available, and use the polyfill if not available
-const EventSource = NativeEventSource || EventSourcePolyfill;
+function _getXSRFToken() {
+  // from @jupyterlab/services
+  // https://github.com/jupyterlab/jupyterlab/blob/69223102d717f3d3e9f976d32e657a4e2456e85d/packages/services/src/contents/index.ts#L1178-L1184
+  let cookie = "";
+  try {
+    cookie = document.cookie;
+  } catch (e) {
+    // e.g. SecurityError in case of CSP Sandbox
+    return null;
+  }
+  // extracts the value of the cookie named `_xsrf`
+  // by picking up everything between `_xsrf=` and the next semicolon or end-of-line
+  // `\b` ensures word boundaries, so it doesn't pick up `something_xsrf=`...
+  const xsrfTokenMatch = cookie.match("\\b_xsrf=([^;]*)\\b");
+  if (xsrfTokenMatch) {
+    return xsrfTokenMatch[1];
+  }
+  return null;
+}
+
+/* throw this to close the event stream */
+class EventStreamClose extends Error {}
+/* throw this to close the event stream */
+class EventStreamRetry extends Error {}
 
 /**
  * Build (and optionally launch) a repository by talking to a BinderHub API endpoint
@@ -12,10 +34,14 @@ export class BinderRepository {
    *
    * @param {string} providerSpec Spec of the form <provider>/<repo>/<ref> to pass to the binderhub API.
    * @param {URL} buildEndpointUrl API URL of the build endpoint to talk to
-   * @param {string} [buildToken] Optional JWT based build token if this binderhub installation requires using build tokens
-   * @param {boolean} [buildOnly] Opt out of launching built image by default by passing `build_only` param
+   * @param {Object} [options] - optional arguments
+   * @param {string} [options.buildToken] Optional JWT based build token if this binderhub installation requires using build tokens
+   * @param {boolean} [options.buildOnly] Opt out of launching built image by default by passing `build_only` param
+   * @param {string} [options.apiToken] Optional Bearer token for authenticating requests
    */
-  constructor(providerSpec, buildEndpointUrl, buildToken, buildOnly) {
+  constructor(providerSpec, buildEndpointUrl, options) {
+    const { apiToken, buildToken, buildOnly } = options || {};
+
     this.providerSpec = providerSpec;
     // Make sure that buildEndpointUrl is a real URL - this ensures hostname is properly set
     if (!(buildEndpointUrl instanceof URL)) {
@@ -40,8 +66,10 @@ export class BinderRepository {
     if (buildOnly) {
       this.buildUrl.searchParams.append("build_only", "true");
     }
+    this.apiToken = apiToken;
 
     this.eventIteratorQueue = null;
+    this.abortSignal = null;
   }
 
   /**
@@ -67,26 +95,100 @@ export class BinderRepository {
    * @returns {AsyncIterable<Line>} An async iterator yielding responses from the API as they come in
    */
   fetch() {
-    this.eventSource = new EventSource(this.buildUrl);
+    const headers = {};
+    this.abortController = new AbortController();
+
+    if (this.apiToken && this.apiToken.length > 0) {
+      headers["Authorization"] = `Bearer ${this.apiToken}`;
+    } else {
+      const xsrf = _getXSRFToken();
+      if (xsrf) {
+        headers["X-Xsrftoken"] = xsrf;
+      }
+    }
+    // setTimeout(() => this.close(), 1000);
     return new EventIterator((queue) => {
       this.eventIteratorQueue = queue;
-      this.eventSource.onerror = () => {
-        queue.push({
-          phase: "failed",
-          message: "Failed to connect to event stream\n",
-        });
-        queue.stop();
-      };
-
-      this.eventSource.addEventListener("message", (event) => {
-        // console.log("message received")
-        // console.log(event)
-        const data = JSON.parse(event.data);
-        // FIXME: fix case of phase/state upstream
-        if (data.phase) {
-          data.phase = data.phase.toLowerCase();
-        }
-        queue.push(data);
+      fetchEventSource(this.buildUrl, {
+        headers,
+        // signal used for closing
+        signal: this.abortController.signal,
+        // openWhenHidden leaves connection open (matches default)
+        // otherwise fetch-event closes connections,
+        // which would be nice if our javascript handled restarting messages better
+        openWhenHidden: true,
+        onopen: (response) => {
+          if (response.ok) {
+            return; // everything's good
+          } else if (
+            response.status >= 400 &&
+            response.status < 500 &&
+            response.status !== 429
+          ) {
+            queue.push({
+              phase: "failed",
+              message: `Failed to connect to event stream: ${response.status} - ${response.text}\n`,
+            });
+            throw new EventStreamClose();
+          } else {
+            queue.push({
+              phase: "unknown",
+              message: `Error connecting to event stream, retrying: ${response.status} - ${response.text}\n`,
+            });
+            throw new EventStreamRetry();
+          }
+        },
+
+        onclose: () => {
+          if (!queue.isStopped) {
+            // close called before queue finished
+            queue.push({
+              phase: "failed",
+              message: `Event stream closed unexpectedly\n`,
+            });
+            queue.stop();
+            // throw new EventStreamClose();
+          }
+        },
+        onerror: (error) => {
+          console.log("Event stream error", error);
+          if (error.name === "EventStreamRetry") {
+            // if we don't re-raise, connection will be retried;
+            queue.push({
+              phase: "unknown",
+              message: `Error in event stream: ${error}\n`,
+            });
+            return;
+          }
+          if (
+            !(error.name === "EventStreamClose" || error.name === "AbortError")
+          ) {
+            // errors _other_ than EventStreamClose get displayed
+            queue.push({
+              phase: "failed",
+              message: `Error in event stream: ${error}\n`,
+            });
+          }
+          queue.stop();
+          // need to rethrow to prevent reconnection
+          throw error;
+        },
+
+        onmessage: (event) => {
+          if (!event.data || event.data === "") {
+            // onmessage is called for the empty lines
+            return;
+          }
+          const data = JSON.parse(event.data);
+          // FIXME: fix case of phase/state upstream
+          if (data.phase) {
+            data.phase = data.phase.toLowerCase();
+          }
+          queue.push(data);
+          if (data.phase === "failed") {
+            throw new EventStreamClose();
+          }
+        },
       });
     });
   }
@@ -95,12 +197,15 @@ export class BinderRepository {
    * Close the EventSource connection to the BinderHub API if it is open
    */
   close() {
-    if (this.eventSource !== undefined) {
-      this.eventSource.close();
-    }
-    if (this.eventIteratorQueue !== null) {
+    if (this.eventIteratorQueue) {
       // Stop any currently running fetch() iterations
       this.eventIteratorQueue.stop();
+      this.eventIteratorQueue = null;
+    }
+    if (this.abortController) {
+      // close event source
+      this.abortController.abort();
+      this.abortController = null;
     }
   }
 

js/packages/binderhub-client/package.json

@@ -14,7 +14,7 @@
   },
   "homepage": "https://github.com/jupyterhub/binderhub#readme",
   "dependencies": {
-    "event-source-polyfill": "^1.0.31",
+    "@microsoft/fetch-event-source": "^2.0.1",
     "event-iterator": "^2.0.0"
   }
 }