fix: propagate log-config changes

If Theia is started with the "--log-config" option the 'LogLevelCliContribution' watches
for file changes and fires a 'logConfigChangedEvent'. This event was not listened to.
Therefore already existing 'ILogger' levels were not updated. This is now fixed by
notifying loggers about log config changes to update their log level.

Signed-off-by: Stefan Dirix <sdirix@eclipsesource.com>

Contributed on behalf of STMicroelectronics

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - [Previous Changelogs](https://github.com/eclipse-theia/theia/tree/master/doc/changelogs/)
 
+## v1.42.0 - 09/28/2023
+
+- [core] fixed logger level propagation when log config file changes at runtime [#12566](https://github.com/eclipse-theia/theia/pull/12566) - Contributed on behalf of STMicroelectronics.
+
 ## v1.41.0 - 08/31/2023
 
 - [application-package] added handling to quit the electron app when the backend fails to start [#12778](https://github.com/eclipse-theia/theia/pull/12778) - Contributed on behalf of STMicroelectronics.

packages/core/src/common/logger-protocol.ts

@@ -38,6 +38,7 @@ export interface ILogLevelChangedEvent {
 
 export interface ILoggerClient {
     onLogLevelChanged(event: ILogLevelChangedEvent): void;
+    onLogConfigChanged(): void;
 }
 
 @injectable()
@@ -49,6 +50,9 @@ export class DispatchingLoggerClient implements ILoggerClient {
         this.clients.forEach(client => client.onLogLevelChanged(event));
     }
 
+    onLogConfigChanged(): void {
+        this.clients.forEach(client => client.onLogConfigChanged());
+    }
 }
 
 export const rootLoggerName = 'root';

packages/core/src/common/logger-watcher.ts

@@ -22,11 +22,15 @@ import { ILoggerClient, ILogLevelChangedEvent } from './logger-protocol';
 export class LoggerWatcher {
 
     getLoggerClient(): ILoggerClient {
-        const emitter = this.onLogLevelChangedEmitter;
+        const logLevelEmitter = this.onLogLevelChangedEmitter;
+        const logConfigEmitter = this.onLogConfigChangedEmitter;
         return {
             onLogLevelChanged(event: ILogLevelChangedEvent): void {
-                emitter.fire(event);
-            }
+                logLevelEmitter.fire(event);
+            },
+            onLogConfigChanged(): void {
+                logConfigEmitter.fire();
+            },
         };
     }
 
@@ -36,6 +40,12 @@ export class LoggerWatcher {
         return this.onLogLevelChangedEmitter.event;
     }
 
+    private onLogConfigChangedEmitter = new Emitter<void>();
+
+    get onLogConfigChanged(): Event<void> {
+        return this.onLogConfigChangedEmitter.event;
+    }
+
     // FIXME: get rid of it, backend services should as well set a client on the server
     fireLogLevelChanged(event: ILogLevelChangedEvent): void {
         this.onLogLevelChangedEmitter.fire(event);

packages/core/src/common/logger.ts

@@ -261,6 +261,11 @@ export class Logger implements ILogger {
                 }
             });
         });
+
+        /* Refetch log level if overall config in backend changed. */
+        this.loggerWatcher.onLogConfigChanged(() => {
+            this._logLevel = this.created.then(_ => this.server.getLogLevel(this.name));
+        });
     }
 
     setLogLevel(logLevel: number): Promise<void> {

packages/core/src/node/console-logger-server.ts

@@ -17,7 +17,7 @@
 import { inject, injectable, postConstruct } from 'inversify';
 import { LoggerWatcher } from '../common/logger-watcher';
 import { LogLevelCliContribution } from './logger-cli-contribution';
-import { ILoggerServer, ILoggerClient, ConsoleLogger } from '../common/logger-protocol';
+import { ILoggerServer, ILoggerClient, ConsoleLogger, rootLoggerName } from '../common/logger-protocol';
 
 @injectable()
 export class ConsoleLoggerServer implements ILoggerServer {
@@ -32,9 +32,13 @@ export class ConsoleLoggerServer implements ILoggerServer {
 
     @postConstruct()
     protected init(): void {
+        this.setLogLevel(rootLoggerName, this.cli.defaultLogLevel);
         for (const name of Object.keys(this.cli.logLevels)) {
             this.setLogLevel(name, this.cli.logLevels[name]);
         }
+        this.cli.onLogConfigChanged(() => {
+            this.client?.onLogConfigChanged();
+        });
     }
 
     async setLogLevel(name: string, newLogLevel: number): Promise<void> {