make a /boot/GRIST_BOOT_KEY page for diagnosing configuration problems (#850)

This is a start at a page for diagnosing problems while setting up Grist. Starting to add some diagnostics based on feedback in github issues. We should make Grist installation easier! But when there is a problem it should be easier to diagnose than it is now, and this may help. The page is ugly and doesn't have many diagnostics yet, but we can iterate.

Visit `/boot` on a Grist server for tips on how to use this feature.

app/client/boot.ts

@@ -0,0 +1,259 @@
+import { AppModel } from 'app/client/models/AppModel';
+import { createAppPage } from 'app/client/ui/createAppPage';
+import { pagePanels } from 'app/client/ui/PagePanels';
+import { BootProbeInfo, BootProbeResult } from 'app/common/BootProbe';
+import { removeTrailingSlash } from 'app/common/gutil';
+import { getGristConfig } from 'app/common/urlUtils';
+import { Disposable, dom, Observable, styled, UseCBOwner } from 'grainjs';
+
+const cssBody = styled('div', `
+  padding: 20px;
+  overflow: auto;
+`);
+
+const cssHeader = styled('div', `
+  padding: 20px;
+`);
+
+const cssResult = styled('div', `
+  max-width: 500px;
+`);
+
+/**
+ *
+ * A "boot" page for inspecting the state of the Grist installation.
+ *
+ * TODO: deferring using any localization machinery so as not
+ * to have to worry about its failure modes yet, but it should be
+ * fine as long as assets served locally are used.
+ *
+ */
+export class Boot extends Disposable {
+
+  // The back end will offer a set of probes (diagnostics) we
+  // can use. Probes have unique IDs.
+  public probes: Observable<BootProbeInfo[]>;
+
+  // Keep track of probe results we have received, by probe ID.
+  public results: Map<string, Observable<BootProbeResult>>;
+
+  // Keep track of probe requests we are making, by probe ID.
+  public requests: Map<string, BootProbe>;
+
+  constructor(_appModel: AppModel) {
+    super();
+    // Setting title in constructor seems to be how we are doing this,
+    // based on other similar pages.
+    document.title = 'Booting Grist';
+    this.probes = Observable.create(this, []);
+    this.results = new Map();
+    this.requests = new Map();
+  }
+
+  /**
+   * Set up the page. Uses the generic Grist layout with an empty
+   * side panel, just for convenience. Could be made a lot prettier.
+   */
+  public buildDom() {
+    const config = getGristConfig();
+    const errMessage = config.errMessage;
+    if (!errMessage) {
+      // Probe tool URLs are relative to the current URL. Don't trust configuration,
+      // because it may be buggy if the user is here looking at the boot page
+      // to figure out some problem.
+      const url = new URL(removeTrailingSlash(document.location.href));
+      url.pathname += '/probe';
+      fetch(url.href).then(async resp => {
+        const _probes = await resp.json();
+        this.probes.set(_probes.probes);
+      }).catch(e => reportError(e));
+    }
+
+    const rootNode = dom('div',
+      dom.domComputed(
+        use => {
+          return pagePanels({
+            leftPanel: {
+              panelWidth: Observable.create(this, 240),
+              panelOpen: Observable.create(this, false),
+              hideOpener: true,
+              header: null,
+              content: null,
+            },
+            headerMain: cssHeader(dom('h1', 'Grist Boot')),
+            contentMain: this.buildBody(use, {errMessage}),
+          });
+        }
+      ),
+      );
+    return rootNode;
+  }
+
+  /**
+   * The body of the page is very simple right now, basically a
+   * placeholder.  Make a section for each probe, and kick them off in
+   * parallel, showing results as they come in.
+   */
+  public buildBody(use: UseCBOwner, options: {errMessage?: string}) {
+    if (options.errMessage) {
+      return cssBody(cssResult(this.buildError()));
+    }
+    return cssBody([
+      ...use(this.probes).map(probe => {
+        const {id} = probe;
+        let result = this.results.get(id);
+        if (!result) {
+          result = Observable.create(this, {});
+          this.results.set(id, result);
+        }
+        let request = this.requests.get(id);
+        if (!request) {
+          request = new BootProbe(id, this);
+          this.requests.set(id, request);
+        }
+        request.start();
+        return cssResult(
+          this.buildResult(probe, use(result), probeDetails[id]));
+      }),
+    ]);
+  }
+
+  /**
+   * This is used when there is an attempt to access the boot page
+   * but something isn't right - either the page isn't enabled, or
+   * the key in the URL is wrong. Give the user some information about
+   * how to set things up.
+   */
+  public buildError() {
+    return dom(
+      'div',
+      dom('p',
+          'A diagnostics page can be made available at:',
+          dom('blockquote', '/boot/GRIST_BOOT_KEY'),
+          'GRIST_BOOT_KEY is an environment variable ',
+          ' set before Grist starts. It should only',
+          ' contain characters that are valid in a URL.',
+          ' It should be a secret, since no authentication is needed',
+          ' to visit the diagnostics page.'),
+      dom('p',
+          'You are seeing this page because either the key is not set,',
+          ' or it is not in the URL.'),
+    );
+  }
+
+  /**
+   * An ugly rendering of information returned by the probe.
+   */
+  public buildResult(info: BootProbeInfo, result: BootProbeResult,
+                     details: ProbeDetails|undefined) {
+    const out: (HTMLElement|string|null)[] = [];
+    out.push(dom('h2', info.name));
+    if (details) {
+      out.push(dom('p', '> ', details.info));
+    }
+    if (result.verdict) {
+      out.push(dom('pre', result.verdict));
+    }
+    if (result.success !== undefined) {
+      out.push(result.success ? '✅' : '❌');
+    }
+    if (result.done === true) {
+      out.push(dom('p', 'no fault detected'));
+    }
+    if (result.details) {
+      for (const [key, val] of Object.entries(result.details)) {
+        out.push(dom(
+          'div',
+          key,
+          dom('input', dom.prop('value', JSON.stringify(val)))));
+      }
+    }
+    return out;
+  }
+}
+
+/**
+ * Represents a single diagnostic.
+ */
+export class BootProbe {
+  constructor(public id: string, public boot: Boot) {
+    const url = new URL(removeTrailingSlash(document.location.href));
+    url.pathname = url.pathname + '/probe/' + id;
+    fetch(url.href).then(async resp => {
+      const _probes: BootProbeResult = await resp.json();
+      const ob = boot.results.get(id);
+      if (ob) {
+        ob.set(_probes);
+      }
+    }).catch(e => console.error(e));
+  }
+
+  public start() {
+    let result = this.boot.results.get(this.id);
+    if (!result) {
+      result = Observable.create(this.boot, {});
+      this.boot.results.set(this.id, result);
+    }
+  }
+}
+
+/**
+ * Create a stripped down page to show boot information.
+ * Make sure the API isn't used since it may well be unreachable
+ * due to a misconfiguration, especially in multi-server setups.
+ */
+createAppPage(appModel => {
+  return dom.create(Boot, appModel);
+}, {
+  useApi: false,
+});
+
+/**
+ * Basic information about diagnostics is kept on the server,
+ * but it can be useful to show extra details and tips in the
+ * client.
+ */
+const probeDetails: Record<string, ProbeDetails> = {
+  'boot-page': {
+    info: `
+This boot page should not be too easy to access. Either turn
+it off when configuration is ok (by unsetting GRIST_BOOT_KEY)
+or make GRIST_BOOT_KEY long and cryptographically secure.
+`,
+  },
+
+  'health-check': {
+    info: `
+Grist has a small built-in health check often used when running
+it as a container.
+`,
+  },
+
+  'host-header': {
+    info: `
+Requests arriving to Grist should have an accurate Host
+header. This is essential when GRIST_SERVE_SAME_ORIGIN
+is set.
+`,
+  },
+
+  'system-user': {
+    info: `
+It is good practice not to run Grist as the root user.
+`,
+  },
+
+  'reachable': {
+    info: `
+The main page of Grist should be available.
+`
+  },
+};
+
+/**
+ * Information about the probe.
+ */
+interface ProbeDetails {
+  info: string;
+}
+

app/client/models/AppModel.ts

@@ -146,6 +146,11 @@ export interface AppModel {
   switchUser(user: FullUser, org?: string): Promise<void>;
 }
 
+export interface TopAppModelOptions {
+  /** Defaults to true. */
+  useApi?: boolean;
+}
+
 export class TopAppModelImpl extends Disposable implements TopAppModel {
   public readonly isSingleOrg: boolean;
   public readonly productFlavor: ProductFlavor;
@@ -163,14 +168,16 @@ export class TopAppModelImpl extends Disposable implements TopAppModel {
   // up new widgets - that seems ok.
   private readonly _widgets: AsyncCreate<ICustomWidget[]>;
 
-  constructor(window: {gristConfig?: GristLoadConfig}, public readonly api: UserAPI = newUserAPIImpl()) {
+  constructor(window: {gristConfig?: GristLoadConfig},
+              public readonly api: UserAPI = newUserAPIImpl(),
+              public readonly options: TopAppModelOptions = {}) {
     super();
     setErrorNotifier(this.notifier);
     this.isSingleOrg = Boolean(window.gristConfig && window.gristConfig.singleOrg);
     this.productFlavor = getFlavor(window.gristConfig && window.gristConfig.org);
     this._gristConfig = window.gristConfig;
     this._widgets = new AsyncCreate<ICustomWidget[]>(async () => {
-      const widgets = await this.api.getWidgets();
+      const widgets = this.options.useApi === false ? [] : await this.api.getWidgets();
       this.customWidgets.set(widgets);
       return widgets;
     });
@@ -180,7 +187,9 @@ export class TopAppModelImpl extends Disposable implements TopAppModel {
     this.autoDispose(subscribe(this.currentSubdomain, (use) => this.initialize()));
     this.plugins = this._gristConfig?.plugins || [];
 
-    this.fetchUsersAndOrgs().catch(reportError);
+    if (this.options.useApi !== false) {
+      this.fetchUsersAndOrgs().catch(reportError);
+    }
   }
 
   public initialize(): void {
@@ -237,6 +246,10 @@ export class TopAppModelImpl extends Disposable implements TopAppModel {
 
   private async _doInitialize() {
     this.appObs.set(null);
+    if (this.options.useApi === false) {
+      AppModelImpl.create(this.appObs, this, null, null, {error: 'no-api', status: 500});
+      return;
+    }
     try {
       const {user, org, orgError} = await this.api.getSessionActive();
       if (this.isDisposed()) { return; }

app/client/ui/createAppPage.ts

@@ -1,6 +1,6 @@
 import {get as getBrowserGlobals} from 'app/client/lib/browserGlobals';
 import {setupLocale} from 'app/client/lib/localization';
-import {AppModel, TopAppModelImpl} from 'app/client/models/AppModel';
+import {AppModel, TopAppModelImpl, TopAppModelOptions} from 'app/client/models/AppModel';
 import {reportError, setUpErrorHandling} from 'app/client/models/errors';
 import {buildSnackbarDom} from 'app/client/ui/NotifyUI';
 import {addViewportTag} from 'app/client/ui/viewport';
@@ -14,10 +14,12 @@ const G = getBrowserGlobals('document', 'window');
  * Sets up the application model, error handling, and global styles, and replaces
  * the DOM body with the result of calling `buildAppPage`.
  */
-export function createAppPage(buildAppPage: (appModel: AppModel) => DomContents) {
+export function createAppPage(
+  buildAppPage: (appModel: AppModel) => DomContents,
+  modelOptions: TopAppModelOptions = {}) {
   setUpErrorHandling();
 
-  const topAppModel = TopAppModelImpl.create(null, {});
+  const topAppModel = TopAppModelImpl.create(null, {}, undefined, modelOptions);
 
   addViewportTag();
   attachCssRootVars(topAppModel.productFlavor);