From 9f7dc10fbe7fae2d2aa774091a4dabfc232a933e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20Adel=C3=B6w?= <freben@gmail.com>
Date: Fri, 5 Mar 2021 15:13:52 +0100
Subject: [PATCH] Show a Not Found message when navigating to a nonexistent
 entity
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Fredrik Adelöw <freben@gmail.com>
---
 .changeset/rotten-beds-itch.md                |  5 ++++
 .../EntityPageLayout/EntityPageLayout.tsx     | 30 +++++++++++++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/rotten-beds-itch.md

diff --git a/.changeset/rotten-beds-itch.md b/.changeset/rotten-beds-itch.md
new file mode 100644
index 0000000000..c046e71572
--- /dev/null
+++ b/.changeset/rotten-beds-itch.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog': patch
+---
+
+Show a Not Found message when navigating to a nonexistent entity
diff --git a/plugins/catalog/src/components/EntityPageLayout/EntityPageLayout.tsx b/plugins/catalog/src/components/EntityPageLayout/EntityPageLayout.tsx
index 34378d5496..6f9899ff82 100644
--- a/plugins/catalog/src/components/EntityPageLayout/EntityPageLayout.tsx
+++ b/plugins/catalog/src/components/EntityPageLayout/EntityPageLayout.tsx
@@ -18,7 +18,15 @@ import {
   ENTITY_DEFAULT_NAMESPACE,
   RELATION_OWNED_BY,
 } from '@backstage/catalog-model';
-import { Content, Header, HeaderLabel, Page, Progress } from '@backstage/core';
+import {
+  Content,
+  Header,
+  HeaderLabel,
+  Link,
+  Page,
+  Progress,
+  WarningPanel,
+} from '@backstage/core';
 import {
   EntityContext,
   EntityRefLinks,
@@ -125,7 +133,11 @@ export const EntityPageLayout = ({ children }: PropsWithChildren<{}>) => {
         )}
       </Header>
 
-      {loading && <Progress />}
+      {loading && (
+        <Content>
+          <Progress />
+        </Content>
+      )}
 
       {entity && <Tabbed.Layout>{children}</Tabbed.Layout>}
 
@@ -134,6 +146,19 @@ export const EntityPageLayout = ({ children }: PropsWithChildren<{}>) => {
           <Alert severity="error">{error.toString()}</Alert>
         </Content>
       )}
+
+      {!loading && !error && !entity && (
+        <Content>
+          <WarningPanel title="Entity not found">
+            There is no {kind} with the requested{' '}
+            <Link to="https://backstage.io/docs/features/software-catalog/references">
+              kind, namespace, and name
+            </Link>
+            .
+          </WarningPanel>
+        </Content>
+      )}
+
       <UnregisterEntityDialog
         open={confirmationDialogOpen}
         entity={entity!}
@@ -143,4 +168,5 @@ export const EntityPageLayout = ({ children }: PropsWithChildren<{}>) => {
     </Page>
   );
 };
+
 EntityPageLayout.Content = Tabbed.Content;