docs: Uninstall Gateway (#4966)

https://discord.com/channels/1228082899023298741/1239053156965679115

---------

Signed-off-by: Jamil <jamilbk@users.noreply.github.com>
Co-authored-by: Brian Manifold <bmanifold@users.noreply.github.com>
Co-authored-by: Andrew Dryga <andrew@dryga.com>
Co-authored-by: Reactor Scram <ReactorScram@users.noreply.github.com>
Co-authored-by: Gabi <gabrielalejandro7@gmail.com>

website/src/app/kb/administer/uninstall/_page.tsx

@@ -0,0 +1,6 @@
+"use client";
+import Content from "./readme.mdx";
+
+export default function _Page() {
+  return <Content />;
+}

website/src/app/kb/administer/uninstall/page.tsx

@@ -0,0 +1,17 @@
+import _Page from "./_page";
+import { Metadata } from "next";
+import LastUpdated from "@/components/LastUpdated";
+
+export const metadata: Metadata = {
+  title: "Uninstall Firezone • Firezone Docs",
+  description: "How to uninstall Firezone",
+};
+
+export default function Page() {
+  return (
+    <>
+      <_Page />
+      <LastUpdated dirname={__dirname} />
+    </>
+  );
+}

website/src/app/kb/administer/uninstall/readme.mdx

@@ -0,0 +1,77 @@
+import SupportOptions from "@/components/SupportOptions";
+import { TabsGroup, TabsItem } from "@/components/DocsTabs";
+import Alert from "@/components/DocsAlert";
+
+# Uninstall Firezone Gateway
+
+This guide covers how to uninstall the Firezone Gateway from your server(s).
+
+{/* TODO: add Alert and link to client uninstall docs when that's complete */}
+
+## Step 1: Stop the Gateway and remove relevant files
+
+Use the appropriate instructions below to stop and remove the Gateway depending
+on how it was installed:
+
+<TabsGroup>
+<TabsItem title="Docker" active>
+
+1. Stop the container:
+
+   ```
+   docker stop firezone-gateway
+   ```
+
+1. Remove the container and its volumes:
+
+   ```
+   docker rm --volumes firezone-gateway
+   ```
+
+1. Remove the image:
+
+   ```
+   docker rmi ghcr.io/firezone/gateway:1
+   ```
+
+1. Remove the cache directory:
+
+   ```
+   sudo rm -rf /var/lib/firezone
+   ```
+
+</TabsItem>
+<TabsItem title="systemd">
+
+1. Stop the service:
+
+   ```
+   sudo systemctl stop firezone-gateway
+   ```
+
+1. Disable the service:
+
+   ```
+   sudo systemctl disable firezone-gateway
+   ```
+
+1. Remove all relevant files:
+
+   ```
+   sudo rm -rf /etc/systemd/system/firezone-gateway.service \
+        /usr/local/bin/firezone-gateway \
+        /usr/local/bin/firezone-gateway-init \
+        /var/lib/firezone
+   ```
+
+</TabsItem>
+</TabsGroup>
+
+## Step 2 (optional): Delete the data from the admin portal
+
+If you want to remove the Gateway's data from the admin portal as well, navigate
+to the Site where the Gateway was running, click `(see all)` next to the
+`Online Gateways` header, and then delete the offline Gateway corresponding to the
+Gateway you just uninstalled.
+
+<SupportOptions />

website/src/app/kb/administer/upgrading/readme.mdx

@@ -5,7 +5,7 @@ import Image from "next/image";
 import Alert from "@/components/DocsAlert";
 import SupportOptions from "@/components/SupportOptions";
 
-# Upgrading Gateways
+# Upgrade Gateways
 
 Firezone Gateways are designed to be easily upgraded with little or no planned
 downtime for your organization. This guide will walk you through the steps to

website/src/components/KbSidebar/index.tsx

@@ -124,7 +124,7 @@ export default function KbSidebar() {
                 <Item href="/kb/administer">Overview</Item>
               </li>
               <li>
-                <Item href="/kb/administer/upgrading">Upgrading Gateways</Item>
+                <Item href="/kb/administer/upgrading">Upgrade Gateways</Item>
               </li>
               <li>
                 <Item href="/kb/administer/backup-restore">
@@ -139,6 +139,9 @@ export default function KbSidebar() {
                   Troubleshooting
                 </Item>
               </li>
+              <li>
+                <Item href="/kb/administer/uninstall">Uninstall Firezone</Item>
+              </li>
             </Collapse>
           </li>
           <li>