feat: Railway compliant cache headers

davidmytton · davidmytton · commit 1234d3488f18 · 2026-06-05T13:33:45.000Z
diff --git a/internal/handlers/advertise.go b/internal/handlers/advertise.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -30,6 +31,7 @@ func AdvertiseHandler(aj *arcjet.Client) (http.Handler, error) {
 			renderDenied(w, r, decision)
 			return
 		}
+		middleware.SetNewsletterCacheHeaders(w)
 		web.Render(w, r, "advertise.html", AdvertiseData{})
 	}), nil
 }
diff --git a/internal/handlers/confirm.go b/internal/handlers/confirm.go
@@ -4,6 +4,7 @@ import (
 	"net/http"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -25,6 +26,7 @@ func ConfirmHandler(aj *arcjet.Client) (http.Handler, error) {
 			renderDenied(w, r, decision)
 			return
 		}
+		middleware.SetNoStoreCacheHeaders(w)
 		web.Render(w, r, "confirm.html", PrivacyData{})
 	}), nil
 }
diff --git a/internal/handlers/denied.go b/internal/handlers/denied.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/rss"
 	"github.com/consoledotdev/home/web"
 )
@@ -43,6 +44,7 @@ func deniedMessage(decision arcjet.Decision) string {
 func renderDenied(w http.ResponseWriter, r *http.Request, decision arcjet.Decision) {
 	logDenied(r, decision)
 
+	middleware.SetNoStoreCacheHeaders(w)
 	w.WriteHeader(http.StatusForbidden)
 	web.Render(w, r, "denied.html", deniedData{
 		Heading: "Request blocked",
@@ -76,6 +78,7 @@ func renderDeniedRSS(w http.ResponseWriter, r *http.Request, decision arcjet.Dec
 		return
 	}
 
+	middleware.SetNoStoreCacheHeaders(w)
 	w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")
 	w.WriteHeader(http.StatusForbidden)
 	w.Write([]byte(xml.Header))
diff --git a/internal/handlers/generate.go b/internal/handlers/generate.go
@@ -9,6 +9,7 @@ import (
 	"log/slog"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/notion"
 	"github.com/consoledotdev/home/web"
 )
@@ -60,6 +61,7 @@ func GenerateHandler(aj *arcjet.Client, notionClient *notion.NotionClient) (http
 			Preview:        fmt.Sprintf("%s - the best tools for developers", strings.Join(names, ", ")),
 			NewsletterDate: newsletterDate.Format("2006-01-02"),
 		}
+		middleware.SetNoStoreCacheHeaders(w)
 		web.Render(w, r, "generate.html", data)
 	}), nil
 }
diff --git a/internal/handlers/landing1.go b/internal/handlers/landing1.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/cache"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -38,6 +39,7 @@ func Landing1Handler(aj *arcjet.Client, swrCache *cache.SwrCache) (http.Handler,
 			Betas:          betas,
 			NewsletterDate: newsletterDate.Format("2 January 2006"),
 		}
+		middleware.SetNewsletterCacheHeaders(w)
 		web.Render(w, r, "landing-1.html", data)
 	}), nil
 }
diff --git a/internal/handlers/privacy.go b/internal/handlers/privacy.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -30,6 +31,7 @@ func PrivacyHandler(aj *arcjet.Client) (http.Handler, error) {
 			renderDenied(w, r, decision)
 			return
 		}
+		middleware.SetNewsletterCacheHeaders(w)
 		web.Render(w, r, "privacy.html", PrivacyData{})
 	}), nil
 }
diff --git a/internal/handlers/root.go b/internal/handlers/root.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/cache"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/notion"
 	"github.com/consoledotdev/home/web"
 )
@@ -51,6 +52,7 @@ func RootHandler(aj *arcjet.Client, swrCache *cache.SwrCache) (http.Handler, err
 			Betas:          betas,
 			NewsletterDate: newsletterDate.Format("2006-01-02"),
 		}
+		middleware.SetNewsletterCacheHeaders(w)
 		web.Render(w, r, "index.html", data)
 	}), nil
 }
diff --git a/internal/handlers/rss_betas.go b/internal/handlers/rss_betas.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/cache"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/rss"
 )
 
@@ -85,6 +86,7 @@ func RssBetasHandler(aj *arcjet.Client, swrCache *cache.SwrCache) (http.Handler,
 			return
 		}
 
+		middleware.SetNewsletterCacheHeaders(w)
 		w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")
 		w.Write(x)
 	}), nil
diff --git a/internal/handlers/rss_everything.go b/internal/handlers/rss_everything.go
@@ -11,6 +11,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/cache"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/rss"
 )
 
@@ -104,6 +105,7 @@ func RssEverythingHandler(aj *arcjet.Client, swrCache *cache.SwrCache) (http.Han
 			return
 		}
 
+		middleware.SetNewsletterCacheHeaders(w)
 		w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")
 		w.Write(x)
 	}), nil
diff --git a/internal/handlers/rss_tools.go b/internal/handlers/rss_tools.go
@@ -11,6 +11,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/cache"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/internal/rss"
 )
 
@@ -89,6 +90,7 @@ func RssToolsHandler(aj *arcjet.Client, swrCache *cache.SwrCache) (http.Handler,
 			return
 		}
 
+		middleware.SetNewsletterCacheHeaders(w)
 		w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")
 		w.Write(x)
 	}), nil
diff --git a/internal/handlers/selection-criteria.go b/internal/handlers/selection-criteria.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/arcjet/arcjet-go"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -30,6 +31,7 @@ func SelectionCriteriaHandler(aj *arcjet.Client) (http.Handler, error) {
 			renderDenied(w, r, decision)
 			return
 		}
+		middleware.SetNewsletterCacheHeaders(w)
 		web.Render(w, r, "selection-criteria.html", SelectionCriteriaData{})
 	}), nil
 }
diff --git a/internal/handlers/subscribe.go b/internal/handlers/subscribe.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/arcjet/arcjet-go"
 	"github.com/consoledotdev/home/internal/mailchimp"
+	"github.com/consoledotdev/home/internal/middleware"
 	"github.com/consoledotdev/home/web"
 )
 
@@ -54,6 +55,8 @@ func SubscribeHandler(aj *arcjet.Client, mc *mailchimp.Client) (http.Handler, er
 	}
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		middleware.SetNoStoreCacheHeaders(w)
+
 		email := r.FormValue("email")
 		if email == "" {
 			http.Error(w, "email is required", http.StatusBadRequest)
diff --git a/internal/middleware/cache_control.go b/internal/middleware/cache_control.go
@@ -0,0 +1,87 @@
+package middleware
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+const (
+	browserMaxAgeSeconds     = 300
+	staleWhileRevalidate     = 600
+	staleIfError             = 86400
+	staticAssetMaxAgeSeconds = 2592000
+	staticAssetSWRSeconds    = 86400
+)
+
+var londonLocation = mustLoadLocation("Europe/London")
+
+func mustLoadLocation(name string) *time.Location {
+	loc, err := time.LoadLocation(name)
+	if err != nil {
+		return time.UTC
+	}
+	return loc
+}
+
+// SetNewsletterCacheHeaders configures caching for weekly newsletter-driven pages
+// and feeds. Browser caching stays short, while CDN caching lasts until the next
+// Thursday 08:00 UK publish window.
+func SetNewsletterCacheHeaders(w http.ResponseWriter) {
+	sMaxAge := secondsUntilNextNewsletterPublish(time.Now())
+
+	w.Header().Set(
+		"Cache-Control",
+		fmt.Sprintf(
+			"public, max-age=%d, s-maxage=%d, stale-while-revalidate=%d, stale-if-error=%d",
+			browserMaxAgeSeconds,
+			sMaxAge,
+			staleWhileRevalidate,
+			staleIfError,
+		),
+	)
+}
+
+// SetStaticAssetCacheHeaders configures long-lived caching for static assets.
+func SetStaticAssetCacheHeaders(w http.ResponseWriter) {
+	w.Header().Set(
+		"Cache-Control",
+		fmt.Sprintf(
+			"public, max-age=%d, s-maxage=%d, stale-while-revalidate=%d",
+			staticAssetMaxAgeSeconds,
+			staticAssetMaxAgeSeconds,
+			staticAssetSWRSeconds,
+		),
+	)
+}
+
+// SetNoStoreCacheHeaders prevents responses from being stored by browsers or CDNs.
+func SetNoStoreCacheHeaders(w http.ResponseWriter) {
+	w.Header().Set("Cache-Control", "no-store")
+}
+
+func secondsUntilNextNewsletterPublish(now time.Time) int {
+	nowUK := now.In(londonLocation)
+
+	publish := time.Date(
+		nowUK.Year(),
+		nowUK.Month(),
+		nowUK.Day(),
+		8, 0, 0, 0,
+		londonLocation,
+	)
+
+	// Thursday is 4 in Go's time.Weekday where Sunday is 0.
+	daysUntilThursday := (int(time.Thursday) - int(nowUK.Weekday()) + 7) % 7
+	publish = publish.AddDate(0, 0, daysUntilThursday)
+
+	if !publish.After(nowUK) {
+		publish = publish.AddDate(0, 0, 7)
+	}
+
+	seconds := int(publish.Sub(nowUK).Seconds())
+	if seconds < 60 {
+		return 60
+	}
+	return seconds
+}
diff --git a/main.go b/main.go
@@ -122,7 +122,10 @@ func main() {
 
 	// Serve files from the embedded /web/static directory at /static
 	fileServer := http.FileServer(http.FS(fs))
-	mux.Handle("GET /static/", chain.Then(http.StripPrefix("/static/", fileServer)))
+	mux.Handle("GET /static/", chain.Then(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		middleware.SetStaticAssetCacheHeaders(w)
+		http.StripPrefix("/static/", fileServer).ServeHTTP(w, r)
+	})))
 
 	// Serve favicon.ico and robots.txt
 	mux.Handle("GET /favicon.ico", chain.ThenFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -131,6 +134,7 @@ func main() {
 			http.NotFound(w, r)
 			return
 		}
+		middleware.SetStaticAssetCacheHeaders(w)
 		w.Write(data)
 	}))
 	mux.Handle("GET /robots.txt", chain.ThenFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -139,10 +143,12 @@ func main() {
 			http.NotFound(w, r)
 			return
 		}
+		middleware.SetStaticAssetCacheHeaders(w)
 		w.Write(data)
 	}))
 
 	mux.Handle("GET /health", chain.ThenFunc(func(w http.ResponseWriter, r *http.Request) {
+		middleware.SetNoStoreCacheHeaders(w)
 		w.Write([]byte(`OK`))
 	}))
 
@@ -166,6 +172,7 @@ func main() {
 
 	// Catch-all 404 handler - must be last
 	mux.Handle("GET /", chain.ThenFunc(func(w http.ResponseWriter, r *http.Request) {
+		middleware.SetNoStoreCacheHeaders(w)
 		w.WriteHeader(http.StatusNotFound)
 		web.Render(w, r, "404.html", nil)
 	}))

Original file line number	Diff line number	Diff line change
`@@ -5,6 +5,7 @@ import (`
`5`	`5`	`"net/http"`
`6`	`6`
`7`	`7`	`"github.com/arcjet/arcjet-go"`
	`8`	`+ "github.com/consoledotdev/home/internal/middleware"`
`8`	`9`	`"github.com/consoledotdev/home/web"`
`9`	`10`	`)`
`10`	`11`
`@@ -30,6 +31,7 @@ func AdvertiseHandler(aj *arcjet.Client) (http.Handler, error) {`
`30`	`31`	`renderDenied(w, r, decision)`
`31`	`32`	`return`
`32`	`33`	`}`
	`34`	`+ middleware.SetNewsletterCacheHeaders(w)`
`33`	`35`	`web.Render(w, r, "advertise.html", AdvertiseData{})`
`34`	`36`	`}), nil`
`35`	`37`	`}`
Original file line number	Diff line number	Diff line change
`@@ -4,6 +4,7 @@ import (`
`4`	`4`	`"net/http"`
`5`	`5`
`6`	`6`	`"github.com/arcjet/arcjet-go"`
	`7`	`+ "github.com/consoledotdev/home/internal/middleware"`
`7`	`8`	`"github.com/consoledotdev/home/web"`
`8`	`9`	`)`
`9`	`10`
`@@ -25,6 +26,7 @@ func ConfirmHandler(aj *arcjet.Client) (http.Handler, error) {`
`25`	`26`	`renderDenied(w, r, decision)`
`26`	`27`	`return`
`27`	`28`	`}`
	`29`	`+ middleware.SetNoStoreCacheHeaders(w)`
`28`	`30`	`web.Render(w, r, "confirm.html", PrivacyData{})`
`29`	`31`	`}), nil`
`30`	`32`	`}`
Original file line number	Diff line number	Diff line change
`@@ -9,6 +9,7 @@ import (`
`9`	`9`	`"log/slog"`
`10`	`10`
`11`	`11`	`"github.com/arcjet/arcjet-go"`
	`12`	`+ "github.com/consoledotdev/home/internal/middleware"`
`12`	`13`	`"github.com/consoledotdev/home/internal/notion"`
`13`	`14`	`"github.com/consoledotdev/home/web"`
`14`	`15`	`)`
`@@ -60,6 +61,7 @@ func GenerateHandler(aj arcjet.Client, notionClient notion.NotionClient) (http`
`60`	`61`	`Preview: fmt.Sprintf("%s - the best tools for developers", strings.Join(names, ", ")),`
`61`	`62`	`NewsletterDate: newsletterDate.Format("2006-01-02"),`
`62`	`63`	`}`
	`64`	`+ middleware.SetNoStoreCacheHeaders(w)`
`63`	`65`	`web.Render(w, r, "generate.html", data)`
`64`	`66`	`}), nil`
`65`	`67`	`}`
Original file line number	Diff line number	Diff line change
`@@ -7,6 +7,7 @@ import (`
`7`	`7`
`8`	`8`	`"github.com/arcjet/arcjet-go"`
`9`	`9`	`"github.com/consoledotdev/home/internal/cache"`
	`10`	`+ "github.com/consoledotdev/home/internal/middleware"`
`10`	`11`	`"github.com/consoledotdev/home/web"`
`11`	`12`	`)`
`12`	`13`
`@@ -38,6 +39,7 @@ func Landing1Handler(aj arcjet.Client, swrCache cache.SwrCache) (http.Handler,`
`38`	`39`	`Betas: betas,`
`39`	`40`	`NewsletterDate: newsletterDate.Format("2 January 2006"),`
`40`	`41`	`}`
	`42`	`+ middleware.SetNewsletterCacheHeaders(w)`
`41`	`43`	`web.Render(w, r, "landing-1.html", data)`
`42`	`44`	`}), nil`
`43`	`45`	`}`
Original file line number	Diff line number	Diff line change
`@@ -8,6 +8,7 @@ import (`
`8`	`8`
`9`	`9`	`"github.com/arcjet/arcjet-go"`
`10`	`10`	`"github.com/consoledotdev/home/internal/cache"`
	`11`	`+ "github.com/consoledotdev/home/internal/middleware"`
`11`	`12`	`"github.com/consoledotdev/home/internal/notion"`
`12`	`13`	`"github.com/consoledotdev/home/web"`
`13`	`14`	`)`
`@@ -51,6 +52,7 @@ func RootHandler(aj arcjet.Client, swrCache cache.SwrCache) (http.Handler, err`
`51`	`52`	`Betas: betas,`
`52`	`53`	`NewsletterDate: newsletterDate.Format("2006-01-02"),`
`53`	`54`	`}`
	`55`	`+ middleware.SetNewsletterCacheHeaders(w)`
`54`	`56`	`web.Render(w, r, "index.html", data)`
`55`	`57`	`}), nil`
`56`	`58`	`}`
Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,7 @@ import (`
`10`	`10`
`11`	`11`	`"github.com/arcjet/arcjet-go"`
`12`	`12`	`"github.com/consoledotdev/home/internal/cache"`
	`13`	`+ "github.com/consoledotdev/home/internal/middleware"`
`13`	`14`	`"github.com/consoledotdev/home/internal/rss"`
`14`	`15`	`)`
`15`	`16`
`@@ -85,6 +86,7 @@ func RssBetasHandler(aj arcjet.Client, swrCache cache.SwrCache) (http.Handler,`
`85`	`86`	`return`
`86`	`87`	`}`
`87`	`88`
	`89`	`+ middleware.SetNewsletterCacheHeaders(w)`
`88`	`90`	`w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")`
`89`	`91`	`w.Write(x)`
`90`	`92`	`}), nil`
Original file line number	Diff line number	Diff line change
`@@ -11,6 +11,7 @@ import (`
`11`	`11`
`12`	`12`	`"github.com/arcjet/arcjet-go"`
`13`	`13`	`"github.com/consoledotdev/home/internal/cache"`
	`14`	`+ "github.com/consoledotdev/home/internal/middleware"`
`14`	`15`	`"github.com/consoledotdev/home/internal/rss"`
`15`	`16`	`)`
`16`	`17`
`@@ -104,6 +105,7 @@ func RssEverythingHandler(aj arcjet.Client, swrCache cache.SwrCache) (http.Han`
`104`	`105`	`return`
`105`	`106`	`}`
`106`	`107`
	`108`	`+ middleware.SetNewsletterCacheHeaders(w)`
`107`	`109`	`w.Header().Set("Content-Type", "application/rss+xml; charset=UTF-8")`
`108`	`110`	`w.Write(x)`
`109`	`111`	`}), nil`