Make test_event.cc more resilient

- Work on both Debian and RedHat systems.
- Ignore test if authentication log cannot be found or cannot be read.

server/core/test/test_event.cc

@@ -462,8 +462,35 @@ int test_events()
     return errors;
 }
 
+string get_auth_log()
+{
+    string name;
+
+    const char DEBIAN_AUTH_LOG[] = "/var/log/auth.log";
+    const char REDHAT_AUTH_LOG[] = "/var/log/secure";
+
+    if (access(DEBIAN_AUTH_LOG, F_OK) == 0)
+    {
+        cout << "notice: " << DEBIAN_AUTH_LOG << " exists, assuming a Debian system." << endl;
+        name = DEBIAN_AUTH_LOG;
+    }
+    else if (access(REDHAT_AUTH_LOG, F_OK) == 0)
+    {
+        cout << "notice: " << REDHAT_AUTH_LOG << " exists, assuming a RedHat system." << endl;
+        name = REDHAT_AUTH_LOG;
+    }
+    else
+    {
+        cout << "warning: Neither " << DEBIAN_AUTH_LOG << ", nor " << REDHAT_AUTH_LOG << " exists." << endl;
+    }
+
+    return name;
+}
+
 int test_logging()
 {
+    int errors = 0;
+
     event::set_log_facility(event::AUTHENTICATION_FAILURE, LOG_AUTH);
     event::set_log_level(event::AUTHENTICATION_FAILURE, LOG_ERR);
 
@@ -481,6 +508,23 @@ int test_logging()
 
     MXS_LOG_EVENT(event::AUTHENTICATION_FAILURE, "%s", id.c_str());
 
+    string name = get_auth_log();
+
+    if (name.empty())
+    {
+        cout << "warning: Don't know where to look for authentication errors. Ignoring test." << endl;
+    }
+    else
+    {
+        if (access(name.c_str(), R_OK) != 0)
+        {
+            cout << "warning: Cannot read " << name << ", ignoring test." << endl;
+            name.clear();
+        }
+    }
+
+    if (!name.empty())
+    {
         // We have no control over how quickly syslog messages are flushed
         // to the file. So, we try a few times before giving up.
 
@@ -494,8 +538,7 @@ int test_logging()
 
             sleep(1);
 
-        const char* zName = "/var/log/auth.log";
+            ifstream in(name);
-        ifstream in(zName);
 
             if (in)
             {
@@ -511,13 +554,16 @@ int test_logging()
             }
             else
             {
-            cerr << "error: Could not open '" << zName << "'." << endl;
+                cerr << "error: Could not open '" << name << "'." << endl;
                 attempts = MAX_ATTEMPTS;
             }
         }
         while (!found && (attempts < MAX_ATTEMPTS));
 
-    return found ? 0 : 1;
+        errors = found ? 0 : 1;
+    }
+
+    return errors;
 }
 
 }