Bug 1812738 - allow user to set Glean log level

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 [Full changelog](https://github.com/mozilla/glean/compare/v52.6.0...main)
 
+* General
+  * Allow user to control the log level of the Glean ([#2459](https://github.com/mozilla/glean/pull/2459))
+
 # v52.6.0 (2023-04-20)
 
 [Full changelog](https://github.com/mozilla/glean/compare/v52.5.0...v52.6.0)

glean-core/android/src/main/java/mozilla/telemetry/glean/Glean.kt

@@ -482,6 +482,15 @@ open class GleanInternalAPI internal constructor() {
         gleanSetLogPings(value)
     }
 
+    /**
+     * Sets the log level option for Glean internal processes.
+     *
+     * @param value One of the following options: "Debug", "Error", "Info", "Off", "Trace", "Warn".
+     */
+    fun setLogLevel(value: String) {
+        gleanSetLogLevel(value)
+    }
+
     /**
      * TEST ONLY FUNCTION.
      * This is called by the GleanTestRule, to enable test mode.

glean-core/ios/Glean/Glean.swift

@@ -352,6 +352,14 @@ public class Glean {
         gleanSetSourceTags(tags)
     }
 
+    /// Sets the log level option for Glean internal processes.
+    ///
+    /// - parameters:
+    ///    * value: One of the following options: "Debug", "Error", "Info", "Off", "Trace", "Warn".
+    public func setLogLevel(_ value: String) {
+        gleanSetLogLevel(value)
+    }
+
     /// Set configuration for metrics' disabled property, typically from remote_settings
     /// experiment or rollout.
     ///

glean-core/rlb/src/lib.rs

@@ -266,6 +266,15 @@ pub fn set_source_tags(tags: Vec<String>) {
     glean_core::glean_set_source_tags(tags);
 }
 
+/// Sets the log level for the `log` crate.
+///
+/// # Arguments
+///
+/// * `value` - A string representation of the `log::LevelFilter` enum.
+pub fn set_log_level(value: String) {
+    glean_core::glean_set_log_level(value);
+}
+
 /// Returns a timestamp corresponding to "now" with millisecond precision.
 pub fn get_timestamp_ms() -> u64 {
     glean_core::get_timestamp_ms()

glean-core/src/glean.udl

@@ -35,6 +35,7 @@ namespace glean {
     boolean glean_set_debug_view_tag(string tag);
     boolean glean_set_source_tags(sequence<string> tags);
     void glean_set_log_pings(boolean value);
+    void glean_set_log_level(string log_level);
 
     void glean_handle_client_active();
     void glean_handle_client_inactive();

glean-core/src/lib.rs

@@ -25,6 +25,7 @@ use std::thread;
 use std::time::Duration;
 
 use crossbeam_channel::unbounded;
+use log::{set_max_level, LevelFilter};
 use once_cell::sync::{Lazy, OnceCell};
 use uuid::Uuid;
 
@@ -864,6 +865,29 @@ pub fn glean_set_log_pings(value: bool) {
     }
 }
 
+/// Sets the log level for the `log` crate.
+///
+/// # Arguments
+///
+/// * `value` - A string representation of the `log::LevelFilter` enum.
+pub fn glean_set_log_level(value: String) {
+    let filter_level = match &value[..] {
+        "Debug" => LevelFilter::Debug,
+        "Error" => LevelFilter::Error,
+        "Info" => LevelFilter::Info,
+        "Off" => LevelFilter::Off,
+        "Trace" => LevelFilter::Trace,
+        "Warn" => LevelFilter::Warn,
+        _ => {
+            // We were unable to map to a logging level, so we return without setting anything.
+            log::error!("Invalid logging level: {}", value);
+            return;
+        }
+    };
+
+    set_max_level(filter_level);
+}
+
 /// Performs the collection/cleanup operations required by becoming active.
 ///
 /// This functions generates a baseline ping with reason `active`