Add basic MaxCtrl test

The test does a very minimal check for MaxCtrl functionality.

maxscale-system-test/maxctrl_basic.cpp

@@ -0,0 +1,31 @@
+/**
+ * Minimal MaxCtrl sanity check
+ */
+
+#include "testconnections.h"
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    int rc = test.maxscales->ssh_node_f(0, false, "maxctrl help list servers");
+    test.assert(rc == 0, "`help list servers` should work");
+
+    rc = test.maxscales->ssh_node_f(0, false, "maxctrl --tsv list servers|grep 'Master, Running'");
+    test.assert(rc == 0, "`list servers` should return at least one row with: Master, Running");
+
+    rc = test.maxscales->ssh_node_f(0, false, "maxctrl set server server1 maintenance");
+    test.assert(rc == 0, "`set server` should work");
+
+    rc = test.maxscales->ssh_node_f(0, false, "maxctrl --tsv list servers|grep 'Maintenance'");
+    test.assert(rc == 0, "`list servers` should return at least one row with: Maintanance");
+
+    rc = test.maxscales->ssh_node_f(0, false, "maxctrl clear server server1 maintenance");
+    test.assert(rc == 0, "`clear server` should work");
+
+    rc = test.maxscales->ssh_node_f(0, false, "maxctrl --tsv list servers|grep 'Maintenance'");
+    test.assert(rc != 0, "`list servers` should have no rows with: Maintanance");
+
+    test.check_maxscale_alive();
+    return test.global_result;
+}