Add Doris Schoolhouse and clean pending homelab changes

pihole/serenity/keepalived.conf

@@ -0,0 +1,32 @@
+global_defs {
+    router_id pihole_backup
+}
+
+vrrp_script chk_pihole_web {
+    script "grep -qi ':22FA' /proc/net/tcp /proc/net/tcp6"
+    interval 2
+    fall 2
+    rise 2
+}
+
+vrrp_instance VI_DNS {
+    state BACKUP
+    interface br0
+    virtual_router_id 53
+    priority 90
+    advert_int 1
+    nopreempt
+
+    authentication {
+        auth_type PASS
+        auth_pass CHANGE01
+    }
+
+    virtual_ipaddress {
+        10.5.1.53/24
+    }
+
+    track_script {
+        chk_pihole_web
+    }
+}