[#174] Add error log check back in

classes/hook_callbacks.php

@@ -35,5 +35,7 @@ public static function before_http_headers(\core\hook\output\before_http_headers
         if (class_exists('\core\check\manager')) {
             \tool_heartbeat\check\cachecheck::ping('web');
         }
+
+        lib::process_error_log_ping();
     }
 }

classes/lib.php

@@ -100,5 +100,33 @@ public static function record_cache_checked(int $valueincache, int $valueindb, s
         error_log("Heartbeat cache was checked: " . json_encode($details));
         // @codingStandardsIgnoreEnd
     }
+
+    /**
+     * Handles error logging pinging. This happens on a regular schedule e.g. every 30 mins.
+     * This is used in conjunction with external monitoring services to monitor if the error log is fresh
+     * (or alternatively if it is stale, because the logs are not coming through anymore).
+     */
+    public static function process_error_log_ping() {
+        $lastpinged = get_config('tool_heartbeat', 'errorloglastpinged') ?: 0;
+        $errorperiod = get_config('tool_heartbeat', 'errorlog');
+
+        // If zero/null - disabled - don't do anything.
+        if (empty($errorperiod)) {
+            return;
+        }
+
+        if (($lastpinged + $errorperiod) < time()) {
+            // Update the last pinged time.
+            set_config('errorloglastpinged', time(), 'tool_heartbeat');
+
+            // Log to error_log.
+            $now = userdate(time());
+            $period = format_time($errorperiod);
+
+            // @codingStandardsIgnoreStart
+            error_log("Heartbeat error log test $now, next test expected in $period");
+            // @codingStandardsIgnoreEnd
+        }
+    }
 }
 

lib.php

@@ -31,6 +31,7 @@ function tool_heartbeat_before_http_headers() {
     if (class_exists('\core\check\manager')) {
         \tool_heartbeat\check\cachecheck::ping('web');
     }
+    \tool_heartbeat\lib::process_error_log_ping();
 }
 
 /**

tests/lib_test.php

@@ -47,4 +47,63 @@ public function test_get_allowed_ips() {
         set_config('allowedips_forced', '', 'tool_heartbeat');
         $this->assertEquals('', lib::get_allowed_ips());
     }
+
+    /**
+     * Provides values to test error log ping.
+     * @return array
+     */
+    public function process_error_log_ping_provider(): array {
+        return [
+            'no period set - disabled' => [
+                'errorloglastpinged' => null,
+                'errorlog' => null,
+                'expectedtimebefore' => null,
+            ],
+            'only period set' => [
+                'errorloglastpinged' => null,
+                'errorlog' => 1 * MINSECS,
+                // Update to latest time.
+                'expectedtimebefore' => time() + 10,
+            ],
+            'period has passed, time should change' => [
+                'errorloglastpinged' => 1,
+                'errorlog' => 1 * MINSECS,
+                // Update to latest time.
+                'expectedtimebefore' => time() + 10,
+            ],
+            'period not passed yet, time unchanged' => [
+                'errorloglastpinged' => time(),
+                'errorlog' => 1 * MINSECS,
+                // Remain unchanged, i.e. exactly equal.
+                'expectedtimebefore' => time(),
+            ],
+        ];
+    }
+
+    /**
+     * Tests process_error_log_ping function
+     *
+     * @param int|null $errorloglastpinged next error value to set
+     * @param int|null $errorlog error log value to set
+     * @param bool $expectrun
+     * @dataProvider process_error_log_ping_provider
+     */
+    public function test_process_error_log_ping(?int $errorloglastpinged, ?int $errorlog, ?int $expectedtimebefore) {
+        $this->resetAfterTest(true);
+        set_config('errorloglastpinged', $errorloglastpinged, 'tool_heartbeat');
+        set_config('errorlog', $errorlog, 'tool_heartbeat');
+        lib::process_error_log_ping();
+
+        $valueafter = get_config('tool_heartbeat', 'errorloglastpinged');
+
+        // Assert the time was not set at all.
+        if (is_null($expectedtimebefore)) {
+            $this->assertFalse($valueafter);
+        } else {
+            // New value should have set current time as the last pinged time.
+            // We use less than and add some buffer in the test cases to account
+            // for tests that might happen over a few seconds.
+            $this->assertLessThanOrEqual($expectedtimebefore, $valueafter);
+        }
+    }
 }