chore: only parse INSTANA_TRACING_DISABLE as boolean when value is boolean

Fixed normalizeTracingEnabled to only use INSTANA_TRACING_DISABLE for the
tracing.enabled config when the env var value is 'true' or 'false'. When it
contains instrumentation/group names (e.g., 'logging'), it's now handled by
the separate disable normalizer

Author: aryamohanan

packages/core/src/config/configNormalizers/disable.js

@@ -31,12 +31,10 @@ exports.normalize = function normalize(config) {
 
     if (envDisableConfig !== null) {
       if (envDisableConfig === true) {
-        logger?.debug('[config] env:INSTANA_TRACING_DISABLE = true');
         return true;
       }
 
       if (envDisableConfig === false) {
-        logger?.debug('[config] env:INSTANA_TRACING_DISABLE = false (overrides in-code config)');
         return {};
       }
 

packages/core/src/config/index.js

@@ -251,8 +251,15 @@ function normalizeTracingConfig({ userConfig = {}, defaultConfig = {}, finalConf
  * @param {{ userConfig?: InstanaConfig|null, defaultConfig?: InstanaConfig, finalConfig?: InstanaConfig }} [options]
  */
 function normalizeTracingEnabled({ userConfig = {}, defaultConfig = {}, finalConfig = {} } = {}) {
+  // INSTANA_TRACING_DISABLE can be either:
+  // 1. A boolean ('true'/'false') to enable/disable all tracing
+  // 2. A list of instrumentations/groups to selectively disable
+  // We only use it for tracing.enabled if it's a boolean value
+  const envValue = process.env.INSTANA_TRACING_DISABLE;
+  const isBooleanValue = envValue === 'true' || envValue === 'false';
+
   finalConfig.tracing.enabled = util.resolveBooleanConfigWithInvertedEnv({
-    envVar: 'INSTANA_TRACING_DISABLE',
+    envVar: isBooleanValue ? 'INSTANA_TRACING_DISABLE' : undefined,
     configValue: userConfig.tracing.enabled,
     defaultValue: defaultConfig.tracing.enabled,
     configPath: 'config.tracing.enabled'