Merge pull request ipfs/kubo#7699 from ipfs/fix/dnslink-dir-listing

fix(dnslink-gw): breadcrumbs and CID column when dir listing

This commit was moved from ipfs/kubo@499e011

gateway/core/corehttp/gateway_handler.go

@@ -392,8 +392,9 @@ 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.
@@ -403,13 +404,16 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 		gwURL = ""
 	}
 
+	dnslink := hasDNSLinkOrigin(gwURL, urlPath)
+
 	// See comment above where originalUrlPath is declared.
 	tplData := listingTemplateData{
 		GatewayURL:  gwURL,
+		DNSLink:     dnslink,
 		Listing:     dirListing,
 		Size:        size,
 		Path:        urlPath,
-		Breadcrumbs: breadcrumbs(urlPath),
+		Breadcrumbs: breadcrumbs(urlPath, dnslink),
 		BackLink:    backLink,
 		Hash:        hash,
 	}

gateway/core/corehttp/gateway_indexPage.go

@@ -13,6 +13,7 @@ import (
 // structs for directory listing
 type listingTemplateData struct {
 	GatewayURL  string
+	DNSLink     bool
 	Listing     []directoryItem
 	Size        string
 	Path        string
@@ -34,16 +35,16 @@ type breadcrumb struct {
 	Path string
 }
 
-func breadcrumbs(urlPath string) []breadcrumb {
+func breadcrumbs(urlPath string, dnslinkOrigin bool) []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()
+	contentRoot := segs[1]
 	for i, seg := range segs {
 		if i == 0 {
 			ret = append(ret, breadcrumb{Name: seg})
@@ -55,13 +56,38 @@ 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 the hostname most likely won't have a
+	// public gateway mounted.
+	if dnslinkOrigin {
+		prefix := "/ipns/" + contentRoot
+		for i, crumb := range ret {
+			if strings.HasPrefix(crumb.Path, prefix) {
+				ret[i].Path = strings.Replace(crumb.Path, prefix, "", 1)
+			}
+		}
+		// Make contentRoot breadcrumb link to the website root
+		ret[1].Path = "/"
+	}
+
 	return ret
 }
 
 func shortHash(hash string) string {
 	return (hash[0:4] + "\u2026" + hash[len(hash)-4:])
 }
 
+// helper to detect DNSLink website context
+// (when hostname from gwURL is matching /ipns/<fqdn> in path)
+func hasDNSLinkOrigin(gwURL string, path string) bool {
+	if gwURL != "" {
+		fqdn := stripPort(strings.TrimPrefix(gwURL, "//"))
+		return strings.HasPrefix(path, "/ipns/"+fqdn)
+	}
+	return false
+}
+
 var listingTemplate *template.Template
 
 func init() {

gateway/core/corehttp/gateway_test.go

@@ -391,6 +391,10 @@ func TestIPNSHostnameRedirect(t *testing.T) {
 	}
 }
 
+// Test directory listing on DNSLink website
+// (scenario when Host header is the same as URL hostname)
+// This is basic regression test: additional end-to-end tests
+// can be found in test/sharness/t0115-gateway-dir-listing.sh
 func TestIPNSHostnameBacklinks(t *testing.T) {
 	ns := mockNamesys{}
 	ts, api, ctx := newTestServerAndNode(t, ns)
@@ -437,15 +441,15 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// expect correct backlinks
+	// expect correct links
 	body, err := ioutil.ReadAll(res.Body)
 	if err != nil {
 		t.Fatalf("error reading response: %s", err)
 	}
 	s := string(body)
 	t.Logf("body: %s\n", string(body))
 
-	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"/ipns/example.net\">example.net</a>/<a href=\"/ipns/example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>") {
+	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"//example.net/\">example.net</a>/<a href=\"//example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>") {
 		t.Fatalf("expected a path in directory listing")
 	}
 	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/./..\">") {
@@ -454,6 +458,10 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/file.txt\">") {
 		t.Fatalf("expected file in directory listing")
 	}
+	if !strings.Contains(s, "<a class=\"ipfs-hash\" href=\"https://cid.ipfs.io/#") {
+		// https://github.com/ipfs/dir-index-html/issues/42
+		t.Fatalf("expected links to cid.ipfs.io in CID column when on DNSLink website")
+	}
 	if !strings.Contains(s, k2.Cid().String()) {
 		t.Fatalf("expected hash in directory listing")
 	}
@@ -487,6 +495,10 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	if !strings.Contains(s, "<a href=\"/file.txt\">") {
 		t.Fatalf("expected file in directory listing")
 	}
+	if !strings.Contains(s, "<a class=\"ipfs-hash\" href=\"https://cid.ipfs.io/#") {
+		// https://github.com/ipfs/dir-index-html/issues/42
+		t.Fatalf("expected links to cid.ipfs.io in CID column when on DNSLink website")
+	}
 	if !strings.Contains(s, k.Cid().String()) {
 		t.Fatalf("expected hash in directory listing")
 	}
@@ -511,7 +523,7 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	s = string(body)
 	t.Logf("body: %s\n", string(body))
 
-	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"/ipns/example.net\">example.net</a>/<a href=\"/ipns/example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>/<a href=\"/ipns/example.net/foo%3F%20%23%3C%27/bar\">bar</a>") {
+	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"//example.net/\">example.net</a>/<a href=\"//example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>/<a href=\"//example.net/foo%3F%20%23%3C%27/bar\">bar</a>") {
 		t.Fatalf("expected a path in directory listing")
 	}
 	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/bar/./..\">") {
@@ -545,7 +557,7 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	s = string(body)
 	t.Logf("body: %s\n", string(body))
 
-	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"/ipns/example.net\">example.net</a>") {
+	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"//example.net/\">example.net</a>") {
 		t.Fatalf("expected a path in directory listing")
 	}
 	if !strings.Contains(s, "<a href=\"/good-prefix/\">") {

gateway/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