feat(edge/templates): introduce edge app templates [EE-6209] (#10480)

api/http/handler/templates/utils_fetch_templates.go

@@ -0,0 +1,41 @@
+package templates
+
+import (
+	"net/http"
+
+	portainer "github.com/portainer/portainer/api"
+	httperror "github.com/portainer/portainer/pkg/libhttp/error"
+	"github.com/segmentio/encoding/json"
+)
+
+type listResponse struct {
+	Version   string               `json:"version"`
+	Templates []portainer.Template `json:"templates"`
+}
+
+func (handler *Handler) fetchTemplates() (*listResponse, *httperror.HandlerError) {
+	settings, err := handler.DataStore.Settings().Settings()
+	if err != nil {
+		return nil, httperror.InternalServerError("Unable to retrieve settings from the database", err)
+	}
+
+	templatesURL := settings.TemplatesURL
+	if templatesURL == "" {
+		templatesURL = portainer.DefaultTemplatesURL
+	}
+
+	resp, err := http.Get(templatesURL)
+	if err != nil {
+		return nil, httperror.InternalServerError("Unable to retrieve templates via the network", err)
+	}
+	defer resp.Body.Close()
+
+	var body *listResponse
+	err = json.NewDecoder(resp.Body).Decode(&body)
+	if err != nil {
+		return nil, httperror.InternalServerError("Unable to parse template file", err)
+	}
+
+	return body, nil
+
+}