feat: use git revision as build hash

flake.nix

@@ -81,7 +81,6 @@
               templ
               tailwindcss
               makeWrapper
-              nix
             ];
             preBuild =
               let
@@ -95,7 +94,7 @@
                 inherit (builtins) length genList elemAt;
               in
               ''
-                ldflags+=" -X main.hash=$(nix-hash ${./.})"
+                ldflags+=" -X main.rev=${if lib.hasAttr "rev" self then self.rev else self.dirtyRev}"
 
                 ${builtins.concatStringsSep "\n" (
                   genList (
@@ -144,7 +143,7 @@
                 name = "buildapp";
                 text = ''
                   ${packages.default.preBuild}
-                  go build
+                  go build -ldflags "$ldflags" -o app
                   ./app
                 '';
               })

main.go

@@ -7,14 +7,17 @@ import (
 	"app/pkg/routes/health"
 	"app/pkg/routes/resume"
 	"app/pkg/routes/root"
+
+	"github.com/charmbracelet/log"
 )
 
 var (
-	hash string = "dev";
+	rev string = "foo";
 )
 
 func main() {
-	serv := app.Server{Port: 8080, Hash: hash}
+	log.Info("Current revision: " + rev)
+	serv := app.Server{Port: 8080, Rev: rev}
 
 	serv.AddRoute("GET /", root.Handler)
 	serv.AddRoute("GET /health", health.Handler)

pkg/app/app.go

@@ -14,7 +14,7 @@ import (
 
 type Server struct {
 	Port int16
-	Hash string
+	Rev string
 }
 
 func (serv *Server) Run() {
@@ -35,13 +35,13 @@ func (serv *Server) AddRoute(route string, handler func(app *Server, w http.Resp
 		w.Header().Add("Cache-Control", "no-cache, must-revalidate")
 		hash := r.Header.Get("If-None-Match")
 		// Already cached
-		if hash == serv.Hash {
+		if hash == serv.Rev {
 			log.Info(fmt.Sprintf("Cached %s", log_fmt))
 			w.WriteHeader(http.StatusNotModified)
 			return
 		}
 
-		w.Header().Add("ETag", serv.Hash)
+		w.Header().Add("ETag", serv.Rev)
 		comp, err := handler(serv, w, r)
 
 		if err == nil {

pkg/app/template.templ

@@ -7,14 +7,7 @@ import (
 )
 
 templ NavButton(href string, text string) {
-	<a
-		hx-get={ href }
-		hx-trigger="click"
-		hx-target="main"
-		hx-swap="innerHTML"
-		hx-replace-url="true"
-		class="cursor-pointer"
-	>
+	<a hx-get={ href } hx-trigger="click" hx-target="main" hx-swap="innerHTML" hx-replace-url="true" class="cursor-pointer">
 		{ text }
 	</a>
 }
@@ -54,8 +47,17 @@ templ (app *Server) Template(body templ.Component) {
 					opinions listed here are my own and not representative of any of my employers, past, future, and/or present.
 				</p>
 				<p>
-					Served by me using Nix and Docker. Current build hash: "{ app.Hash }", source code available
-					<a href="https://github.com/drawbu/drawbu.dev" target="_blank" rel="noopener">here</a>.
+					Served by me using Nix and Docker.
+					<br/>
+					Build rev:
+					<a
+						target="_blank"
+						rel="noopener"
+						href={ templ.SafeURL("https://github.com/drawbu/drawbu.dev/tree/" +
+				app.Rev) }
+					>
+						{ app.Rev }
+					</a>
 				</p>
 			</footer>
 		</body>