From 32c26161a231745b7689b2d21370bb81416894c8 Mon Sep 17 00:00:00 2001
From: TEC <git@tecosaur.net>
Date: Mon, 17 Oct 2022 00:58:19 +0800
Subject: [PATCH] Add Caddy HTTP error files

---
 Caddyfile | 22 ++++++++++++++++++++--
 setup.org | 35 ++++++++++++++++++++++++++++++++---
 2 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/Caddyfile b/Caddyfile
index 31352ee..9a44a8e 100644
--- a/Caddyfile
+++ b/Caddyfile
@@ -2,8 +2,26 @@ emacssurvey.tecosaur.net
 
 @dynamic {
 	not path /css/*
+	path /favicon.ico
+	not path /robots.txt
 }
 reverse_proxy @dynamic localhost:8000
 
-root /css/* /opt/emacs-survey/public/css/
-file_server /css/style.css
+root * /opt/emacs-survey/public
+file_server
+
+handle_errors {
+	@404 expression `{err.status_code} == 404`
+	handle @404 {
+		rewrite * /caddy-error.html
+		templates
+		file_server
+	}
+
+	handle {
+		rewrite * /{err.status_code}
+		reverse_proxy https://http.cat {
+			header_up Host {upstream_hostport}
+		}
+	}
+}
diff --git a/setup.org b/setup.org
index 198eec3..4384c6b 100644
--- a/setup.org
+++ b/setup.org
@@ -72,22 +72,51 @@ SETUPDIR=$(dirname "$(readlink --canonicalize-existing "$0")")
 #+end_src
 
 ** Caddy Config
+:PROPERTIES:
+:header-args:prog: :tangle Caddyfile
+:END:
 
 We just need to redirect to Genie for now, which makes for a rather simple
 config. The only complication is serving the static files through Caddy not
 Genie, for performance reasons (Genie recommends against serving static files
 with it).
 
-#+begin_src prog :tangle Caddyfile
+#+begin_src prog
 emacssurvey.tecosaur.net
 
 @dynamic {
 	not path /css/*
+	path /favicon.ico
+	not path /robots.txt
 }
 reverse_proxy @dynamic localhost:8000
+#+end_src
 
-root /css/* /opt/emacs-survey/public/css/
-file_server /css/style.css
+We'll just pass all other requests to the public folder of the Emacs Survey.
+#+begin_src prog
+root * /opt/emacs-survey/public
+file_server
+#+end_src
+
+The only thing left is error pages, for which we'll use a combination of error
+pages and http.cat 🐱.
+
+#+begin_src prog
+handle_errors {
+	@404 expression `{err.status_code} == 404`
+	handle @404 {
+		rewrite * /caddy-error.html
+		templates
+		file_server
+	}
+
+	handle {
+		rewrite * /{err.status_code}
+		reverse_proxy https://http.cat {
+			header_up Host {upstream_hostport}
+		}
+	}
+}
 #+end_src
 
 Just this one file is all it takes to get Caddy set up to our liking 🙂.