Refactor log level configuration (#7695)

* Refactor log level configuration

- Remove STRAPI_LOG_LEVEL environment variable related redundant code.
- Add helpful error message to the current log level configuration
  system.

Signed-off-by: Juho Viitasalo <juho.viitasalo@lildrop.com>

* Fix error message

Signed-off-by: Juho Viitasalo <juho.viitasalo@lildrop.com>

* Fix log level base value

* Fix breaking change

* Add debug message

* Change logger code to use Pino's log level values directly

* Update index.js

Co-authored-by: Alexandre BODIN <alexandrebodin@users.noreply.github.com>

packages/strapi-utils/lib/logger.js

@@ -7,16 +7,25 @@
 const pino = require('pino');
 const _ = require('lodash');
 
-const logLevels = ['fatal', 'error', 'warn', 'info', 'debug', 'trace'];
+const logLevels = Object.keys(pino.levels.values);
 
 function getLogLevel() {
-  if (
-    _.isString(process.env.STRAPI_LOG_LEVEL) &&
-    _.includes(logLevels, process.env.STRAPI_LOG_LEVEL.toLowerCase())
-  ) {
-    return process.env.STRAPI_LOG_LEVEL;
+  if (!_.isString(process.env.STRAPI_LOG_LEVEL)) {
+    // Default value.
+    return 'debug';
   }
-  return 'debug';
+
+  const logLevel = process.env.STRAPI_LOG_LEVEL.toLowerCase();
+
+  if (!_.includes(logLevels, logLevel)) {
+    throw new Error(
+      "Invalid log level set in STRAPI_LOG_LEVEL environment variable. Accepted values are: '" +
+        logLevels.join("', '") +
+        "'."
+    );
+  }
+
+  return logLevel;
 }
 
 function getBool(envVar, defaultValue) {

packages/strapi/lib/middlewares/logger/index.js

@@ -1,5 +1,6 @@
 'use strict';
 const chalk = require('chalk');
+const _ = require('lodash');
 
 const codeToColor = code => {
   return code >= 500
@@ -25,14 +26,30 @@ module.exports = strapi => {
     initialize() {
       const { level, exposeInContext, requests } = strapi.config.middleware.settings.logger;
 
-      if (level) {
-        strapi.log.level = level;
+      const logLevels = Object.keys(strapi.log.levels.values);
+
+      if (!_.includes(logLevels, level)) {
+        throw new Error(
+          "Invalid log level set in middleware configuration. Accepted values are: '" +
+            logLevels.join("', '") +
+            "'."
+        );
       }
 
+      strapi.log.level = level;
+
       if (exposeInContext) {
         strapi.app.context.log = strapi.log;
       }
 
+      const isLogLevelEnvVariableSet = _.isString(process.env.STRAPI_LOG_LEVEL);
+
+      if (isLogLevelEnvVariableSet && strapi.log.levelVal <= 20) {
+        strapi.log.debug(
+          `STRAPI_LOG_LEVEL environment variable is overridden by logger middleware. It only applies outside Strapi's middleware context.`
+        );
+      }
+
       if (requests && strapi.log.levelVal <= 20) {
         strapi.app.use(async (ctx, next) => {
           const start = Date.now();