Add monitor TLS test case

Added a test that verifies the server state is Down when the backend
doesn't support TLS.

maxscale-system-test/CMakeLists.txt

@@ -988,6 +988,9 @@ add_test_executable(mxs2621_lower_case_tables.cpp mxs2621_lower_case_tables mxs2
 # MXS-2631: Duplicate system tables not ignored
 add_test_executable(mxs2631_ignore_system_tables.cpp mxs2631_ignore_system_tables mxs2631_ignore_system_tables LABELS schemarouter BREAKS_REPL REPL_BACKEND)
 
+# MXS-2878: Verify that TLS is required
+add_test_executable(mxs2878_monitor_ssl.cpp mxs2878_monitor_ssl mxs2878_monitor_ssl LABELS REPL_BACKEND)
+
 ############################################
 # END: Normal tests                        #
 ############################################

maxscale-system-test/cnf/maxscale.cnf.template.mxs2878_monitor_ssl

@@ -0,0 +1,47 @@
+[maxscale]
+threads=###threads###
+
+[server1]
+type=server
+address=###node_server_IP_1###
+port=###node_server_port_1###
+protocol=MySQLBackend
+ssl=true
+
+[server2]
+type=server
+address=###node_server_IP_2###
+port=###node_server_port_2###
+protocol=MySQLBackend
+ssl=true
+
+[server3]
+type=server
+address=###node_server_IP_3###
+port=###node_server_port_3###
+protocol=MySQLBackend
+ssl=true
+
+[server4]
+type=server
+address=###node_server_IP_4###
+port=###node_server_port_4###
+protocol=MySQLBackend
+ssl=true
+
+[MySQL-Monitor]
+type=monitor
+module=mysqlmon
+servers=server1,server2,server3,server4
+user=maxskysql
+password=skysql
+
+[CLI]
+type=service
+router=cli
+
+[CLI-Listener]
+type=listener
+service=CLI
+protocol=maxscaled
+socket=default

maxscale-system-test/mxs2878_monitor_ssl.cpp

@@ -0,0 +1,35 @@
+/**
+ * Covers the following bugs:
+ * MXS-2878: Monitor connections do not insist on SSL being used
+ * MXS-2896: Server wrongly in Running state after failure to connect
+ */
+
+#include "testconnections.h"
+#include <sstream>
+
+std::string join(StringSet st)
+{
+    std::ostringstream ss;
+
+    for (const auto& a : st)
+    {
+        ss << a << " ";
+    }
+
+    return ss.str();
+}
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    for (auto srv : {"server1", "server2", "server3", "server4"})
+    {
+        StringSet expected = {"Down"};
+        auto status = test.maxscales->get_server_status(srv);
+        test.expect(status == expected,
+                    "Expected '%s' but got '%s'", join(expected).c_str(), join(status).c_str());
+    }
+
+    return test.global_result;
+}