Document f3s automatic failover configuration in part 7

Add comprehensive section explaining how OpenBSD relayd and httpd
provide automatic failover when the f3s Kubernetes cluster is down.

New content covers:
- Relay-level vs protocol-level routing and why protocol rules don't support failover
- Health check mechanism and automatic table failover
- Correct relayd configuration with f3s first, localhost as backup
- httpd configuration with request rewrite for all paths
- Explanation of why request rewrite is needed to handle deep links
- Benefits of the automatic failover approach

This ensures visitors see a helpful status page instead of connection
errors when the home lab cluster is offline.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/gemfeed/2025-10-02-f3s-kubernetes-with-freebsd-part-7.gmi.tpl b/gemfeed/2025-10-02-f3s-kubernetes-with-freebsd-part-7.gmi.tpl
index c5d76bc5..9a92f204 100644
--- a/gemfeed/2025-10-02-f3s-kubernetes-with-freebsd-part-7.gmi.tpl
+++ b/gemfeed/2025-10-02-f3s-kubernetes-with-freebsd-part-7.gmi.tpl
@@ -687,17 +687,20 @@ This way, f3s traffic uses the relay's default behavior: try the first table, fa
 
 ### OpenBSD httpd fallback configuration
 
-The localhost httpd service on port 8080 serves the fallback content from `/var/www/htdocs/f3s_fallback/`. This directory contains a simple HTML page explaining the situation:
+The localhost httpd service on port 8080 serves the fallback content from `/var/www/htdocs/f3s_fallback/`. This directory contains a simple HTML page explaining the situation.
+
+The key configuration detail is using `request rewrite` to ensure the fallback page is served for ALL paths, not just the root. Without this, accessing paths like `/login?redirect=/files/` would return 404 instead of the fallback page:
 
 ```
 # OpenBSD httpd.conf
-# Fallback for f3s hosts
+# Fallback for f3s hosts - serve fallback page for ALL paths
 server "f3s.foo.zone" {
   listen on * port 8080
   log style forwarded
   location * {
+    # Rewrite all requests to /index.html to show fallback page regardless of path
+    request rewrite "/index.html"
     root "/htdocs/f3s_fallback"
-    directory auto index
   }
 }
 
@@ -705,14 +708,16 @@ server "anki.f3s.foo.zone" {
   listen on * port 8080
   log style forwarded
   location * {
+    request rewrite "/index.html"
     root "/htdocs/f3s_fallback"
-    directory auto index
   }
 }
 
 # ... similar blocks for all f3s hostnames ...
 ```
 
+The `request rewrite "/index.html"` directive ensures that whether someone accesses `/`, `/login`, `/api/status`, or any other path, they all receive the same fallback page. This prevents confusing 404 errors when users have bookmarked specific URLs or follow deep links while the cluster is down.
+
 The fallback page itself is straightforward:
 
 ```html