[bugfix] Fix bug where admin panel could not be accessed at /admin (#…

…427)

* clarify comments

* tidy up static serving + add /admin redirect

internal/router/router.go

@@ -47,7 +47,7 @@ type Router interface {
 	AttachMiddleware(handler gin.HandlerFunc)
 	// Attach 404 NoRoute handler
 	AttachNoRouteHandler(handler gin.HandlerFunc)
-	// Add Gin StaticFile handler
+	// Add Gin StaticFS handler
 	AttachStaticFS(relativePath string, fs http.FileSystem)
 	// Start the router
 	Start()
@@ -62,7 +62,7 @@ type router struct {
 	certManager *autocert.Manager
 }
 
-// Add Gin StaticFile handler
+// Add Gin StaticFS handler
 func (r *router) AttachStaticFS(relativePath string, fs http.FileSystem) {
 	r.engine.StaticFS(relativePath, fs)
 }

internal/web/base.go

@@ -21,7 +21,6 @@ package web
 import (
 	"fmt"
 	"net/http"
-	"os"
 	"path/filepath"
 
 	"github.com/gin-gonic/gin"
@@ -88,18 +87,24 @@ func (m *Module) NotFoundHandler(c *gin.Context) {
 
 // Route satisfies the RESTAPIModule interface
 func (m *Module) Route(s router.Router) error {
-	// serve static files from /assets
-	cwd, err := os.Getwd()
+	// serve static files from assets dir at /assets
+	assetBaseDir := viper.GetString(config.Keys.WebAssetBaseDir)
+	if assetBaseDir == "" {
+		return fmt.Errorf("%s cannot be empty and must be a relative or absolute path", config.Keys.WebAssetBaseDir)
+	}
+	assetPath, err := filepath.Abs(assetBaseDir)
 	if err != nil {
-		return fmt.Errorf("error getting current working directory: %s", err)
+		return fmt.Errorf("error getting absolute path of %s: %s", assetBaseDir, err)
 	}
-	assetBaseDir := viper.GetString(config.Keys.WebAssetBaseDir)
-	assetPath := filepath.Join(cwd, assetBaseDir)
 	s.AttachStaticFS("/assets", fileSystem{http.Dir(assetPath)})
 
-	// Admin panel route, if it exists
-	adminPath := filepath.Join(cwd, assetBaseDir, "/admin")
-	s.AttachStaticFS("/admin", fileSystem{http.Dir(adminPath)})
+	// serve admin panel from within assets dir at /admin/
+	// and redirect /admin to /admin/
+	adminPath := filepath.Join(assetPath, "admin")
+	s.AttachStaticFS("/admin/", fileSystem{http.Dir(adminPath)})
+	s.AttachHandler(http.MethodGet, "/admin", func(c *gin.Context) {
+		c.Redirect(http.StatusMovedPermanently, "/admin/")
+	})
 
 	// serve front-page
 	s.AttachHandler(http.MethodGet, "/", m.baseHandler)