internal/frontend: add a go doc mode to suppress some UI elements

This change adds an option to the server to suppress the unit header
details and the right hand side unit metadata that's shown on pkgsite,
when it's operating in go doc mode. In this go doc mode, it will also
not fetch the deps.dev url or vulnerability information, so that pkgsite
doesn't make unnecessary network calls.

The behavior to allow no modules to match the pattern has also been
folded into go doc mode.

I think we may also want to make some CSS changes too but I think those
would belong in another CL.

Change-Id: I8b6ebb5594f73684d2db41a84e1b6d46ee95d774
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/675957
kokoro-CI: kokoro <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
Reviewed-by: Jonathan Amsterdam <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: matloob

cmd/internal/pkgsite/server.go

@@ -41,7 +41,7 @@ type ServerConfig struct {
 	DevMode          bool
 	DevModeStaticDir string
 	GoRepoPath       string
-	AllowNoModules   bool
+	GoDocMode        bool
 
 	Proxy *proxy.Client // client, or nil; controlled by the -proxy flag
 }
@@ -69,7 +69,7 @@ func BuildServer(ctx context.Context, serverCfg ServerConfig) (*frontend.Server,
 		}
 	} else {
 		var err error
-		cfg.dirs, err = getModuleDirs(ctx, serverCfg.Paths, serverCfg.AllowNoModules)
+		cfg.dirs, err = getModuleDirs(ctx, serverCfg.Paths, serverCfg.GoDocMode)
 		if err != nil {
 			return nil, fmt.Errorf("searching modules: %v", err)
 		}
@@ -114,7 +114,7 @@ func BuildServer(ctx context.Context, serverCfg ServerConfig) (*frontend.Server,
 		return allModules[i].ModulePath < allModules[j].ModulePath
 	})
 
-	return newServer(getters, allModules, cfg.proxy, serverCfg.DevMode, serverCfg.DevModeStaticDir)
+	return newServer(getters, allModules, cfg.proxy, serverCfg.GoDocMode, serverCfg.DevMode, serverCfg.DevModeStaticDir)
 }
 
 // getModuleDirs returns the set of workspace modules for each directory,
@@ -265,7 +265,7 @@ func buildGetters(ctx context.Context, cfg getterConfig) ([]fetch.ModuleGetter,
 	return getters, nil
 }
 
-func newServer(getters []fetch.ModuleGetter, localModules []frontend.LocalModule, prox *proxy.Client, devMode bool, staticFlag string) (*frontend.Server, error) {
+func newServer(getters []fetch.ModuleGetter, localModules []frontend.LocalModule, prox *proxy.Client, goDocMode bool, devMode bool, staticFlag string) (*frontend.Server, error) {
 	lds := fetchdatasource.Options{
 		Getters:              getters,
 		ProxyClientForLatest: prox,
@@ -292,6 +292,7 @@ func newServer(getters []fetch.ModuleGetter, localModules []frontend.LocalModule
 		TemplateFS:       template.TrustedFSFromEmbed(static.FS),
 		StaticFS:         staticFS,
 		DevMode:          devMode,
+		GoDocMode:        goDocMode,
 		LocalMode:        true,
 		LocalModules:     localModules,
 		ThirdPartyFS:     thirdparty.FS,

internal/frontend/server.go

@@ -48,6 +48,7 @@ type Server struct {
 	staticFS           fs.FS
 	thirdPartyFS       fs.FS
 	devMode            bool
+	goDocMode          bool          // running to serve documentation for 'go doc'
 	localMode          bool          // running locally (i.e. ./cmd/pkgsite)
 	localModules       []LocalModule // locally hosted modules; empty in production
 	errorPage          []byte
@@ -90,6 +91,7 @@ type ServerConfig struct {
 	ThirdPartyFS      fs.FS              // for third_party/ directory
 	DevMode           bool
 	LocalMode         bool
+	GoDocMode         bool
 	LocalModules      []LocalModule
 	Reporter          derrors.Reporter
 	VulndbClient      *vuln.Client
@@ -113,6 +115,7 @@ func NewServer(scfg ServerConfig) (_ *Server, err error) {
 		thirdPartyFS:      scfg.ThirdPartyFS,
 		devMode:           scfg.DevMode,
 		localMode:         scfg.LocalMode,
+		goDocMode:         scfg.GoDocMode,
 		localModules:      scfg.LocalModules,
 		templates:         ts,
 		reporter:          scfg.Reporter,

internal/frontend/unit.go

@@ -96,6 +96,10 @@ type UnitPage struct {
 	// Details contains data specific to the type of page being rendered.
 	Details any
 
+	// GoDocMode indicates whether to suppress the unit header and right hand unit metadata.
+	// If set to true, the page will also not have Vulns or a DepsDevURL.
+	GoDocMode bool
+
 	// Vulns holds vulnerability information.
 	Vulns []vuln.Vuln
 
@@ -119,7 +123,7 @@ func (s *Server) serveUnitPage(ctx context.Context, w http.ResponseWriter, r *ht
 		tab = tabMain
 	}
 	// Redirect to clean URL path when tab param is invalid.
-	if _, ok := unitTabLookup[tab]; !ok {
+	if _, ok := unitTabLookup[tab]; !ok || (s.goDocMode && tab != tabMain) {
 		http.Redirect(w, r, r.URL.Path, http.StatusFound)
 		return nil
 	}
@@ -136,7 +140,10 @@ func (s *Server) serveUnitPage(ctx context.Context, w http.ResponseWriter, r *ht
 		return s.fetchServer.ServePathNotFoundPage(w, r, db, info.FullPath, info.ModulePath, info.RequestedVersion)
 	}
 
-	makeDepsDevURL := depsDevURLGenerator(ctx, s.depsDevHTTPClient, um)
+	makeDepsDevURL := func() string { return "" }
+	if !s.goDocMode {
+		makeDepsDevURL = depsDevURLGenerator(ctx, s.depsDevHTTPClient, um)
+	}
 
 	// Use GOOS and GOARCH query parameters to create a build context, which
 	// affects the documentation and synopsis. Omitting both results in an empty
@@ -148,7 +155,7 @@ func (s *Server) serveUnitPage(ctx context.Context, w http.ResponseWriter, r *ht
 	if err != nil {
 		return err
 	}
-	if s.shouldServeJSON(r) {
+	if s.shouldServeJSON(r) && !s.goDocMode {
 		return s.serveJSONPage(w, r, d)
 	}
 
@@ -225,9 +232,13 @@ func (s *Server) serveUnitPage(ctx context.Context, w http.ResponseWriter, r *ht
 		PageLabels:            pageLabels(um),
 		PageType:              pageType(um),
 		RedirectedFromPath:    redirectPath,
-		DepsDevURL:            makeDepsDevURL(),
 		IsGoProject:           isGoProject(um.ModulePath),
 		IsLatestMinor:         lv == latestInfo.MinorVersion,
+		GoDocMode:             s.goDocMode,
+	}
+
+	if !s.goDocMode {
+		page.DepsDevURL = makeDepsDevURL()
 	}
 
 	// Show the banner if there was no error getting the latest major version,
@@ -243,8 +254,10 @@ func (s *Server) serveUnitPage(ctx context.Context, w http.ResponseWriter, r *ht
 		page.MetaDescription = metaDescription(main.DocSynopsis)
 	}
 
-	// Get vulnerability information.
-	page.Vulns = vuln.VulnsForPackage(ctx, um.ModulePath, um.Version, um.Path, s.vulnClient)
+	if !s.goDocMode {
+		// Get vulnerability information.
+		page.Vulns = vuln.VulnsForPackage(ctx, um.ModulePath, um.Version, um.Path, s.vulnClient)
+	}
 
 	s.servePage(ctx, w, tabSettings.TemplateName, page)
 	return nil

static/frontend/unit/_header.tmpl

@@ -10,7 +10,9 @@
   {{template "unit-header-breadcrumbs" .}}
   <div class="go-Main-headerContent">
     {{template "unit-header-title" .}}
-    {{template "unit-header-details" .}}
+    {{if not .GoDocMode}}
+      {{template "unit-header-details" .}}
+    {{end}}
   </div>
 {{end}}
 

static/frontend/unit/unit.tmpl

@@ -23,9 +23,11 @@
     <header class="go-Main-header js-mainHeader">
       {{- block "main-header" .}}{{end -}}
     </header>
-    <aside class="go-Main-aside {{if not (eq .SelectedTab.Name "")}}go-Main-aside--empty{{end}} js-mainAside">
-      {{- block "main-aside" .}}{{end -}}
-    </aside>
+    {{if not .GoDocMode}}
+      <aside class="go-Main-aside {{if not (eq .SelectedTab.Name "")}}go-Main-aside--empty{{end}} js-mainAside">
+        {{- block "main-aside" .}}{{end -}}
+      </aside>
+    {{end}}
     <nav class="go-Main-nav go-Main-nav--sticky js-mainNav" aria-label="Outline">
       {{- block "main-nav" .}}{{end -}}
     </nav>