feat: ability to serve static files (#1174)

Added the configuration key, `service.staticpath`, to serve files from the configuration path on root (/).

Serving static files allows the api service to also serve the frontend content. This is a simple option for deploying Vikunja without needing any other servers or proxies.

Running a complete instance becomes:

    VIKUNJA_SERVICE_STATICPATH=/path/to/frontend ./vikunja

Where `/path/to/frontend` is a copy of Vikunja's frontend static files.

## Implementation

Providing a path, via the configuration or environment, adds a static file middleware to serve the path's contents from root (/).

By default, the configuration path is empty and Vikunja's existing behaviour is unchanged.

Co-authored-by: Graham Miln <graham.miln@dssw.co.uk>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/1174
Reviewed-by: konrad <k@knt.li>
Co-authored-by: grahammiln <grahammiln@noreply.kolaente.de>
Co-committed-by: grahammiln <grahammiln@noreply.kolaente.de>

pkg/config/config.go

@@ -47,6 +47,7 @@ const (
 	ServiceFrontendurl     Key = `service.frontendurl`
 	ServiceEnableCaldav    Key = `service.enablecaldav`
 	ServiceRootpath        Key = `service.rootpath`
+	ServiceStaticpath      Key = `service.staticpath`
 	ServiceMaxItemsPerPage Key = `service.maxitemsperpage`
 	// Deprecated: Use metrics.enabled
 	ServiceEnableMetrics         Key = `service.enablemetrics`
@@ -274,6 +275,7 @@ func InitDefaultConfig() {
 	ServiceEnableCaldav.setDefault(true)
 
 	ServiceRootpath.setDefault(getBinaryDirLocation())
+	ServiceStaticpath.setDefault("")
 	ServiceMaxItemsPerPage.setDefault(50)
 	ServiceEnableMetrics.setDefault(false)
 	ServiceMotd.setDefault("")

pkg/routes/routes.go

@@ -203,6 +203,11 @@ func RegisterRoutes(e *echo.Echo) {
 	// healthcheck
 	e.GET("/health", HealthcheckHandler)
 
+	// static files
+	if static := config.ServiceStaticpath.GetString(); static != "" {
+		e.Use(middleware.Static(static))
+	}
+
 	// CORS_SHIT
 	if config.CorsEnable.GetBool() {
 		e.Use(middleware.CORSWithConfig(middleware.CORSConfig{