fix(gateway): correct breadcrumbs on dnslink site

core/corehttp/gateway_handler.go

@@ -379,8 +379,9 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 
 	hash := resolvedPath.Cid().String()
 
-	// Storage for gateway URL to be used when linking to other rootIDs. This
-	// will be blank unless subdomain resolution is being used for this request.
+	// Gateway root URL to be used when linking to other rootIDs.
+	// This will be blank unless subdomain or DNSLink resolution is being used
+	// for this request.
 	var gwURL string
 
 	// Get gateway hostname and build gateway URL.
@@ -396,11 +397,15 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 		Listing:     dirListing,
 		Size:        size,
 		Path:        urlPath,
-		Breadcrumbs: breadcrumbs(urlPath),
+		Breadcrumbs: breadcrumbs(urlPath, gwURL),
 		BackLink:    backLink,
 		Hash:        hash,
 	}
 
+	// TODO: remove logging below
+	// tplDataJSON, _ := json.MarshalIndent(tplData, "", " ")
+	// fmt.Println(string(tplDataJSON))
+
 	err = listingTemplate.Execute(w, tplData)
 	if err != nil {
 		internalWebError(w, err)

core/corehttp/gateway_indexPage.go

@@ -34,16 +34,17 @@ type breadcrumb struct {
 	Path string
 }
 
-func breadcrumbs(urlPath string) []breadcrumb {
+func breadcrumbs(urlPath string, gwRootURL string) []breadcrumb {
 	var ret []breadcrumb
 
 	p, err := ipfspath.ParsePath(urlPath)
 	if err != nil {
 		// No breadcrumbs, fallback to bare Path in template
 		return ret
 	}
-
 	segs := p.Segments()
+	ns := segs[0]
+	contentRoot := segs[1]
 	for i, seg := range segs {
 		if i == 0 {
 			ret = append(ret, breadcrumb{Name: seg})
@@ -55,6 +56,18 @@ func breadcrumbs(urlPath string) []breadcrumb {
 		}
 	}
 
+	// Drop the /ipns/<fqdn> prefix from breadcrumb Paths when directory listing
+	// on a DNSLink website (loaded due to Host header in HTTP request).
+	// Necessary because gwRootURL won't have a public gateway mounted.
+	if ns == "ipns" && (("//" + contentRoot) == gwRootURL) {
+		prefix := "/ipns/" + contentRoot
+		for i, crumb := range ret {
+			if strings.HasPrefix(crumb.Path, prefix) {
+				ret[i].Path = strings.Replace(crumb.Path, prefix, "", 1)
+			}
+		}
+	}
+
 	return ret
 }
 

core/corehttp/hostname.go

@@ -129,7 +129,7 @@ func HostnameOption() ServeOption {
 				if !gw.NoDNSLink && isDNSLinkRequest(r.Context(), coreAPI, host) {
 					// rewrite path and handle as DNSLink
 					r.URL.Path = "/ipns/" + stripPort(host) + r.URL.Path
-					childMux.ServeHTTP(w, r)
+					childMux.ServeHTTP(w, withHostnameContext(r, host))
 					return
 				}
 
@@ -143,10 +143,6 @@ func HostnameOption() ServeOption {
 			if gw, hostname, ns, rootID, ok := knownSubdomainDetails(host, knownGateways); ok {
 				// Looks like we're using a known gateway in subdomain mode.
 
-				// Add gateway hostname context for linking to other root ids.
-				// Example: localhost/ipfs/{cid}
-				ctx := context.WithValue(r.Context(), "gw-hostname", hostname)
-
 				// Assemble original path prefix.
 				pathPrefix := "/" + ns + "/" + rootID
 
@@ -201,7 +197,7 @@ func HostnameOption() ServeOption {
 				r.URL.Path = pathPrefix + r.URL.Path
 
 				// Serve path request
-				childMux.ServeHTTP(w, r.WithContext(ctx))
+				childMux.ServeHTTP(w, withHostnameContext(r, hostname))
 				return
 			}
 			// We don't have a known gateway. Fallback on DNSLink lookup
@@ -213,7 +209,7 @@ func HostnameOption() ServeOption {
 			if !cfg.Gateway.NoDNSLink && isDNSLinkRequest(r.Context(), coreAPI, host) {
 				// rewrite path and handle as DNSLink
 				r.URL.Path = "/ipns/" + stripPort(host) + r.URL.Path
-				childMux.ServeHTTP(w, r)
+				childMux.ServeHTTP(w, withHostnameContext(r, host))
 				return
 			}
 
@@ -234,6 +230,17 @@ type wildcardHost struct {
 	spec *config.GatewaySpec
 }
 
+// Extends request context to include hostname of a canonical gateway root
+// (subdomain root or dnslink fqdn)
+func withHostnameContext(r *http.Request, hostname string) *http.Request {
+	// This is required for links on directory listing pages to work correctly
+	// on subdomain and dnslink gateways. While DNSlink could read value from
+	// Host header, subdomain gateways have more comples rules (knownSubdomainDetails)
+	// More: https://github.com/ipfs/dir-index-html/issues/42
+	ctx := context.WithValue(r.Context(), "gw-hostname", hostname)
+	return r.WithContext(ctx)
+}
+
 func prepareKnownGateways(publicGateways map[string]*config.GatewaySpec) gatewayHosts {
 	var hosts gatewayHosts