1 files changed, 84 insertions, 0 deletions
diff --git a/src/pybind/mgr/dashboard/frontend/src/app/shared/services/motd-notification.service.ts b/src/pybind/mgr/dashboard/frontend/src/app/shared/services/motd-notification.service.ts
new file mode 100644
index 000000000..d2ee89f9c
--- /dev/null
+++ b/src/pybind/mgr/dashboard/frontend/src/app/shared/services/motd-notification.service.ts
@@ -0,0 +1,84 @@
+import { Injectable, OnDestroy } from '@angular/core';
+
+import * as _ from 'lodash';
+import { BehaviorSubject, EMPTY, Observable, of, Subscription } from 'rxjs';
+import { catchError, delay, mergeMap, repeat, tap } from 'rxjs/operators';
+
+import { Motd, MotdService } from '~/app/shared/api/motd.service';
+import { whenPageVisible } from '../rxjs/operators/page-visibilty.operator';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class MotdNotificationService implements OnDestroy {
+  public motd$: Observable<Motd | null>;
+  public motdSource = new BehaviorSubject<Motd | null>(null);
+
+  private subscription: Subscription;
+  private localStorageKey = 'dashboard_motd_hidden';
+
+  constructor(private motdService: MotdService) {
+    this.motd$ = this.motdSource.asObservable();
+    // Check every 60 seconds for the latest MOTD configuration.
+    this.subscription = of(true)
+      .pipe(
+        mergeMap(() => this.motdService.get()),
+        catchError((error) => {
+          // Do not show an error notification.
+          if (_.isFunction(error.preventDefault)) {
+            error.preventDefault();
+          }
+          return EMPTY;
+        }),
+        tap((motd: Motd | null) => this.processResponse(motd)),
+        delay(60000),
+        repeat(),
+        whenPageVisible()
+      )
+      .subscribe();
+  }
+
+  ngOnDestroy(): void {
+    this.subscription.unsubscribe();
+  }
+
+  hide() {
+    // Store the severity and MD5 of the current MOTD in local or
+    // session storage to be able to show it again if the severity
+    // or message of the latest MOTD has changed.
+    const motd: Motd = this.motdSource.getValue();
+    if (motd) {
+      const value = `${motd.severity}:${motd.md5}`;
+      switch (motd.severity) {
+        case 'info':
+          localStorage.setItem(this.localStorageKey, value);
+          sessionStorage.removeItem(this.localStorageKey);
+          break;
+        case 'warning':
+          sessionStorage.setItem(this.localStorageKey, value);
+          localStorage.removeItem(this.localStorageKey);
+          break;
+      }
+    }
+    this.motdSource.next(null);
+  }
+
+  processResponse(motd: Motd | null) {
+    const value: string | null =
+      sessionStorage.getItem(this.localStorageKey) || localStorage.getItem(this.localStorageKey);
+    let visible: boolean = _.isNull(value);
+    // Force a hidden MOTD to be shown again if the severity or message
+    // has been changed.
+    if (!visible && motd) {
+      const [severity, md5] = value.split(':');
+      if (severity !== motd.severity || md5 !== motd.md5) {
+        visible = true;
+        sessionStorage.removeItem(this.localStorageKey);
+        localStorage.removeItem(this.localStorageKey);
+      }
+    }
+    if (visible) {
+      this.motdSource.next(motd);
+    }
+  }
+}