Introduce environment variable to override connexion settings (#13936)

fixes #13800

contributed on behalf of STMicroelectronics

Signed-off-by: Remi Schnekenburger <rschnekenburger@eclipsesource.com>
Co-authored-by: Philip Langer <planger@eclipsesource.com>

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 <!-- ## not yet released 
 
+- [core] introduce `FRONTEND_CONNECTION_TIMEOUT` environment variable to override application connexion settings. [#13936](https://github.com/eclipse-theia/theia/pull/13936) - Contributed on behalf of STMicroelectronics
+
 <a name="breaking_changes_not_yet_released">[Breaking Changes:](#breaking_changes_not_yet_released)</a> 
 
  -->

packages/core/README.md

@@ -152,6 +152,10 @@ Where `root` is the name of the logger and `INFO` is the log level. These are op
  - If possible, you should set this environment variable:
  - When not set, Theia will allow any origin to access the WebSocket services.
  - When set, Theia will only allow the origins defined in this environment variable.
+- `FRONTEND_CONNECTION_TIMEOUT`
+ - The duration in milliseconds during which the backend keeps the connection contexts for the frontend to reconnect.
+ - This duration defaults to '0' if not set.
+ - If set to negative number, the backend will never close the connection. 
 
 ## Additional Information
 

packages/core/README_TEMPLATE.md

@@ -121,6 +121,10 @@ Where `root` is the name of the logger and `INFO` is the log level. These are op
  - If possible, you should set this environment variable:
  - When not set, Theia will allow any origin to access the WebSocket services.
  - When set, Theia will only allow the origins defined in this environment variable.
+- `FRONTEND_CONNECTION_TIMEOUT`
+ - The duration in milliseconds during which the backend keeps the connection contexts for the frontend to reconnect.
+ - This duration defaults to '0' if not set.
+ - If set to negative number, the backend will never close the connection. 
 
 ## Additional Information
 

packages/core/src/node/messaging/websocket-frontend-connection-service.ts

@@ -105,7 +105,8 @@ export class WebsocketFrontendConnectionService implements FrontendConnectionSer
  socket.on('disconnect', evt => {
  console.info('socked closed');
  channel.disconnect();
- const timeout = BackendApplicationConfigProvider.get().frontendConnectionTimeout;
+
+ const timeout = this.frontendConnectionTimeout();
  const isMarkedForClose = this.channelsMarkedForClose.delete(frontEndId);
  if (timeout === 0 || isMarkedForClose) {
  this.closeConnection(frontEndId, evt);
@@ -124,6 +125,15 @@ export class WebsocketFrontendConnectionService implements FrontendConnectionSer
  markForClose(channelId: string): void {
  this.channelsMarkedForClose.add(channelId);
  }
+
+ private frontendConnectionTimeout(): number {
+ const envValue = Number(process.env['FRONTEND_CONNECTION_TIMEOUT']);
+ if (!isNaN(envValue)) {
+ return envValue;
+ }
+
+ return BackendApplicationConfigProvider.get().frontendConnectionTimeout;
+ }
 }
 
 class ReconnectableSocketChannel extends AbstractChannel {