feat(layer,queue): display templatized page for queued users

internal/queue/layer_options.go

@@ -15,11 +15,11 @@ type LayerOptions struct {
 	KeepAlive time.Duration `mapstructure:"keepAlive"`
 }
 
-func fromStoreOptions(storeOptions store.LayerOptions) (*LayerOptions, error) {
+func fromStoreOptions(storeOptions store.LayerOptions, defaultKeepAlive time.Duration) (*LayerOptions, error) {
 	layerOptions := LayerOptions{
 		Capacity:  1000,
 		Matchers:  []string{"*"},
-		KeepAlive: 30 * time.Second,
+		KeepAlive: defaultKeepAlive,
 	}
 
 	config := mapstructure.DecoderConfig{

internal/queue/options.go

@@ -1,9 +1,29 @@
 package queue
 
-type Options struct{}
+import "time"
+
+type Options struct {
+	TemplateDir      string
+	DefaultKeepAlive time.Duration
+}
 
 type OptionFunc func(*Options)
 
 func defaultOptions() *Options {
-	return &Options{}
+	return &Options{
+		TemplateDir:      "./templates",
+		DefaultKeepAlive: time.Minute,
+	}
+}
+
+func WithTemplateDir(templateDir string) OptionFunc {
+	return func(o *Options) {
+		o.TemplateDir = templateDir
+	}
+}
+
+func WithDefaultKeepAlive(keepAlive time.Duration) OptionFunc {
+	return func(o *Options) {
+		o.DefaultKeepAlive = keepAlive
+	}
 }

internal/queue/queue.go

@@ -3,13 +3,17 @@ package queue
 import (
 	"context"
 	"fmt"
+	"html/template"
 	"net/http"
+	"path/filepath"
+	"sync"
 	"sync/atomic"
 	"time"
 
 	"forge.cadoles.com/Cadoles/go-proxy"
 	"forge.cadoles.com/cadoles/bouncer/internal/proxy/director"
 	"forge.cadoles.com/cadoles/bouncer/internal/store"
+	"github.com/Masterminds/sprig/v3"
 	"github.com/google/uuid"
 	"github.com/pkg/errors"
 	"gitlab.com/wpetit/goweb/logger"
@@ -18,7 +22,14 @@ import (
 const LayerType store.LayerType = "queue"
 
 type Queue struct {
-	adapter           Adapter
+	adapter Adapter
+
+	defaultKeepAlive time.Duration
+
+	templateDir string
+	loadOnce    sync.Once
+	tmpl        *template.Template
+
 	refreshJobRunning uint32
 }
 
@@ -33,7 +44,7 @@ func (q *Queue) Middleware(layer *store.Layer) proxy.Middleware {
 		fn := func(w http.ResponseWriter, r *http.Request) {
 			ctx := r.Context()
 
-			options, err := fromStoreOptions(layer.Options)
+			options, err := fromStoreOptions(layer.Options, q.defaultKeepAlive)
 			if err != nil {
 				logger.Error(ctx, "could not parse layer options", logger.E(errors.WithStack(err)))
 				http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
@@ -102,7 +113,52 @@ func (q *Queue) renderQueuePage(w http.ResponseWriter, r *http.Request, queueNam
 		return
 	}
 
-	http.Error(w, fmt.Sprintf("queued (rank: %d, status: %d/%d)", rank+1, status.Sessions, options.Capacity), http.StatusServiceUnavailable)
+	q.loadOnce.Do(func() {
+		pattern := filepath.Join(q.templateDir, "*.gohtml")
+
+		logger.Info(ctx, "loading queue page templates", logger.F("pattern", pattern))
+
+		tmpl, err := template.New("").Funcs(sprig.FuncMap()).ParseGlob(pattern)
+		if err != nil {
+			logger.Error(ctx, "could not load queue templates", logger.E(errors.WithStack(err)))
+
+			return
+		}
+
+		q.tmpl = tmpl
+	})
+
+	if q.tmpl == nil {
+		logger.Error(ctx, "queue page templates not loaded", logger.E(errors.WithStack(err)))
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+
+		return
+	}
+
+	templateData := struct {
+		QueueName       string
+		LayerOptions    *LayerOptions
+		Rank            int64
+		CurrentSessions int64
+		MaxSessions     int64
+		RefreshRate     int64
+	}{
+		QueueName:       queueName,
+		LayerOptions:    options,
+		Rank:            rank + 1,
+		CurrentSessions: status.Sessions,
+		MaxSessions:     options.Capacity,
+		RefreshRate:     5,
+	}
+
+	w.WriteHeader(http.StatusServiceUnavailable)
+
+	if err := q.tmpl.ExecuteTemplate(w, "queue", templateData); err != nil {
+		logger.Error(ctx, "could not render queue page", logger.E(errors.WithStack(err)))
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+
+		return
+	}
 }
 
 func (q *Queue) refreshQueue(queueName string, keepAlive time.Duration) {
@@ -136,7 +192,9 @@ func New(adapter Adapter, funcs ...OptionFunc) *Queue {
 	}
 
 	return &Queue{
-		adapter: adapter,
+		adapter:          adapter,
+		templateDir:      opts.TemplateDir,
+		defaultKeepAlive: opts.DefaultKeepAlive,
 	}
 }