Suppress some ERRORs logged by Apache Commons JCS

Closes clj-holmes#78

CHANGELOG.md

@@ -8,7 +8,8 @@
   * Replace deprecated clj-time dep with JDK8 java.time interop [#83](https://github.com/clj-holmes/clj-watson/issues/83)
   * Improve feedback during scan
     * Stop suppressing all logging [#68](https://github.com/clj-holmes/clj-watson/issues/68)
-    * Suppress noisy INFO level logging from Apache JCS Commons [#69](https://github.com/clj-holmes/clj-watson/issues/69)
+    * Suppress noisy INFO level logging from Apache Commons JCS [#69](https://github.com/clj-holmes/clj-watson/issues/69)
+    * Suppress specific irrelevant ERROR level logging from Apache Commons JCS [#78](https://github.com/clj-holmes/clj-watson/issues/78)
 
 * v5.1.3 5812615 -- 2024-07-31
   * Address [#60](https://github.com/clj-holmes/clj-watson/issues/60) by updating `org.owasp/dependency-check-core` to 10.0.3.

resources/logback.xml

@@ -5,10 +5,7 @@
     </encoder>
   </appender>
 
-  <!-- Apache Commons JCS is very noisy at the INFO level -->
-  <logger name="org.apache.commons.jcs3" level="WARN" additivity="false">
-    <appender-ref ref="CONSOLE"/>
-  </logger>
+  <!-- See clj-watson.logging-config namespace for suppression of Apache Commons JCS noise -->
 
   <root level="INFO">
     <appender-ref ref="CONSOLE"/>

src/clj_watson/entrypoint.clj

@@ -8,6 +8,7 @@
    [clj-watson.controller.github.vulnerability :as controller.gh.vulnerability]
    [clj-watson.controller.output :as controller.output]
    [clj-watson.controller.remediate :as controller.remediate]
+   [clj-watson.logging-config :as logging-config]
    [clojure.java.io :as io]
    [clojure.tools.reader.edn :as edn]))
 
@@ -44,6 +45,7 @@
 (defn do-scan
   "Indirect entry point for -M usage."
   [opts]
+  (logging-config/init)
   (let [{:keys [fail-on-result output deps-edn-path]} opts
         vulnerabilities (scan* opts)
         contains-vulnerabilities? (->> vulnerabilities

src/clj_watson/logging_config.clj

@@ -0,0 +1,43 @@
+(ns clj-watson.logging-config
+  (:require [clojure.string :as str])
+  (:import [org.slf4j LoggerFactory]
+           [ch.qos.logback.classic.turbo TurboFilter]
+           [ch.qos.logback.classic Level LoggerContext]
+           [ch.qos.logback.core.spi FilterReply]))
+
+(defn- create-custom-filter
+  "Suppress noise from Apache Commons JCS
+  - It's INFO level messages are overly noisy, only log when minimum of WARN.
+  - Suppress specific ERROR level messages from IndexedDiskCache that we have deemed unimportant.
+
+  These suppresssions could be achieved with Logback's EvaluatorFilter but that requires a
+  dependency on the Janino library. We'd like to avoid adding dependencies if possible."
+  []
+  (proxy [TurboFilter] []
+    (decide [marker logger level format params throwable]
+      (cond (and (= Level/ERROR level)
+                 (= "org.apache.commons.jcs3.auxiliary.disk.indexed.IndexedDiskCache"
+                    (.getName logger))
+                 format
+                 (str/includes? format "Not alive and dispose was called"))
+            FilterReply/DENY
+
+            (and (< (.toInt level) Level/WARN_INT)
+                 (str/starts-with? (.getName logger) "org.apache.commons.jcs3"))
+            FilterReply/DENY
+
+            :else
+            FilterReply/NEUTRAL))))
+
+(defn init
+  "Complement `resources/logaback.xml` with some customizations"
+  []
+  (.addTurboFilter (LoggerFactory/getILoggerFactory) (create-custom-filter)))
+
+(comment
+  (.toInt Level/WARN)
+  ;; => 30000
+  (.toInt Level/INFO)
+  ;; => 20000
+
+  :eoc)