Added JSON endpoints. Made Web UI optional.

cmd/csaf_provider/controller.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"embed"
+	"encoding/json"
 	"html/template"
 	"log"
 	"net/http"
@@ -17,6 +18,17 @@ func (me multiError) Error() string {
 	return strings.Join([]string(me), ", ")
 }
 
+func asMultiError(err error) multiError {
+	if err == nil {
+		return nil
+	}
+	e, ok := err.(multiError)
+	if ok {
+		return e
+	}
+	return multiError([]string{err.Error()})
+}
+
 type controller struct {
 	cfg  *config
 	tmpl *template.Template
@@ -27,31 +39,35 @@ func newController(cfg *config) (*controller, error) {
 	c := controller{cfg: cfg}
 	var err error
 
-	if c.tmpl, err = template.ParseFS(tmplFS, "tmpl/*.html"); err != nil {
-		return nil, err
+	if !cfg.NoWebUI {
+		if c.tmpl, err = template.ParseFS(tmplFS, "tmpl/*.html"); err != nil {
+			return nil, err
+		}
 	}
 
 	return &c, nil
 }
 
 func (c *controller) bind(pim *pathInfoMux) {
-	pim.handleFunc("/", c.index)
-	pim.handleFunc("/upload", c.uploadWeb)
-	pim.handleFunc("/create", c.createWeb)
+	if !c.cfg.NoWebUI {
+		pim.handleFunc("/", c.index)
+		pim.handleFunc("/upload", c.web(c.upload, "upload.html"))
+		pim.handleFunc("/create", c.web(c.create, "create.html"))
+	}
+	pim.handleFunc("/api/upload", api(c.upload))
+	pim.handleFunc("/api/create", api(c.create))
 }
 
 func (c *controller) render(rw http.ResponseWriter, tmpl string, arg interface{}) {
 	rw.Header().Set("Content-type", "text/html; charset=utf-8")
+	rw.Header().Set("X-Content-Type-Options", "nosniff")
 	if err := c.tmpl.ExecuteTemplate(rw, tmpl, arg); err != nil {
 		log.Printf("warn: %v\n", err)
 	}
 }
 
 func (c *controller) failed(rw http.ResponseWriter, tmpl string, err error) {
-	if _, ok := err.(multiError); err != nil && !ok {
-		err = multiError([]string{err.Error()})
-	}
-	result := map[string]interface{}{"Error": err}
+	result := map[string]interface{}{"Error": asMultiError(err)}
 	c.render(rw, tmpl, result)
 }
 
@@ -61,19 +77,46 @@ func (c *controller) index(rw http.ResponseWriter, r *http.Request) {
 	})
 }
 
-func (c *controller) createWeb(rw http.ResponseWriter, r *http.Request) {
-	if err := c.create(rw, r); err != nil {
-		c.failed(rw, "create.html", err)
-		return
+func (c *controller) web(
+	fn func(*http.Request) (interface{}, error),
+	tmpl string,
+) func(http.ResponseWriter, *http.Request) {
+
+	return func(rw http.ResponseWriter, r *http.Request) {
+		if content, err := fn(r); err != nil {
+			c.failed(rw, tmpl, err)
+		} else {
+			c.render(rw, tmpl, content)
+		}
 	}
-	c.render(rw, "create.html", nil)
 }
 
-func (c *controller) uploadWeb(rw http.ResponseWriter, r *http.Request) {
-	result, err := c.upload(rw, r)
-	if err != nil {
-		c.failed(rw, "upload.html", err)
-		return
+func writeJSON(rw http.ResponseWriter, content interface{}, code int) {
+	rw.Header().Set("Content-type", "application/json; charset=utf-8")
+	rw.Header().Set("X-Content-Type-Options", "nosniff")
+	rw.WriteHeader(code)
+	if err := json.NewEncoder(rw).Encode(content); err != nil {
+		log.Printf("error: %v\n", err)
+	}
+}
+
+func errorToContent(err error) interface{} {
+	return &struct {
+		Errors multiError `json:"errors"`
+	}{
+		Errors: asMultiError(err),
+	}
+}
+
+func api(
+	fn func(*http.Request) (interface{}, error),
+) func(http.ResponseWriter, *http.Request) {
+
+	return func(rw http.ResponseWriter, r *http.Request) {
+		if content, err := fn(r); err != nil {
+			writeJSON(rw, errorToContent(err), http.StatusBadRequest)
+		} else {
+			writeJSON(rw, content, http.StatusOK)
+		}
 	}
-	c.render(rw, "upload.html", result)
 }