feat(extensions): add the ability to upload and enable an extension (#3345)

* feat(extensions): offline mode mockup

* feat(extensions): offline mode mockup

* feat(api): add support for extensionUpload API operation

* feat(extensions): offline extension upload

* feat(api): better support for extensions in offline mode

* feat(extension): update offline description

* feat(api): introduce local extension manifest

* fix(api): fix LocalExtensionManifestFile value

* feat(api): use a 5second timeout for online extension infos

* feat(extensions): add download archive link

* feat(extensions): add support for offline update

* fix(api): fix issues with offline install and online updates of extensions

* fix(extensions): fix extensions link URL

* fix(extension): hide screenshot in offline mode

api/http/handler/extensions/extension_upload.go

@@ -0,0 +1,75 @@
+package extensions
+
+import (
+	"net/http"
+	"strconv"
+
+	httperror "github.com/portainer/libhttp/error"
+	"github.com/portainer/libhttp/request"
+	"github.com/portainer/libhttp/response"
+	"github.com/portainer/portainer/api"
+)
+
+type extensionUploadPayload struct {
+	License          string
+	ExtensionArchive []byte
+	ArchiveFileName  string
+}
+
+func (payload *extensionUploadPayload) Validate(r *http.Request) error {
+	license, err := request.RetrieveMultiPartFormValue(r, "License", false)
+	if err != nil {
+		return portainer.Error("Invalid license")
+	}
+	payload.License = license
+
+	fileData, fileName, err := request.RetrieveMultiPartFormFile(r, "file")
+	if err != nil {
+		return portainer.Error("Invalid extension archive file. Ensure that the file is uploaded correctly")
+	}
+	payload.ExtensionArchive = fileData
+	payload.ArchiveFileName = fileName
+
+	return nil
+}
+
+func (handler *Handler) extensionUpload(w http.ResponseWriter, r *http.Request) *httperror.HandlerError {
+	payload := &extensionUploadPayload{}
+	err := payload.Validate(r)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusBadRequest, "Invalid request payload", err}
+	}
+
+	extensionIdentifier, err := strconv.Atoi(string(payload.License[0]))
+	if err != nil {
+		return &httperror.HandlerError{http.StatusBadRequest, "Invalid license format", err}
+	}
+	extensionID := portainer.ExtensionID(extensionIdentifier)
+
+	extension := &portainer.Extension{
+		ID: extensionID,
+	}
+
+	_ = handler.ExtensionManager.DisableExtension(extension)
+
+	err = handler.ExtensionManager.InstallExtension(extension, payload.License, payload.ArchiveFileName, payload.ExtensionArchive)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to install extension", err}
+	}
+
+	extension.Enabled = true
+
+	if extension.ID == portainer.RBACExtension {
+		err = handler.upgradeRBACData()
+		if err != nil {
+			return &httperror.HandlerError{http.StatusInternalServerError, "An error occured during database update", err}
+		}
+	}
+
+	err = handler.ExtensionService.Persist(extension)
+	if err != nil {
+		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to persist extension status inside the database", err}
+	}
+
+	return response.Empty(w)
+}