MDEV-18565: Galera mtr-suite fails if galera library is not installed

Currently, running mtr with an incorrect (for example, new or
obsolete) version of wsrep_provider (for example, with the 26
version of libgalera_smm.so) leads to the failure of tests in
several suites with vague error diagnostics.

As for the galera_3nodes suite, the mtr also does not effectively
check all the prerequisites after merge with MDEV-18426 fixes.
For example, tests that using mariabackup do not check for presence
of ss and socat/nc. This is due to improper handling of relative
paths in mtr scripts.

In addition, some tests in different suites can be run without
setting the environment variables such as MTR_GALERA_TFMT, XBSTREAM,
and so on.

To eliminate all these issues, this patch makes the following changes:

1. Added auxiliary wsrep_mtr_check utility (which located in the
mysql-test/lib/My/SafeProcess subdirectory), which compares the
versions of the wsrep API that used by the server and by the wsrep
provider library, and it does this comparison safely, without
accessing the API if the versions do not match.

2. All checks related to the presence of mariabackup and utilities
that necessary for its operation transferred from the local directories
of different mtr suites (from the suite.pm files) to the main suite.pm
file. This not only reduces the amount of code and eliminates duplication
of identical code fragments, but also avoids problems due to the inability
of mtr to consider relative paths to include files when checking skip
combinations.

3. Setting the values of auxiliary environment variables that
are necessary for Galera, SST scripts and mariabackup (to work
properly) is moved to the main mysql-test-run.pl script, so as
not to duplicate this code in different suites, and to avoid
partial corrections of the same errors for different suites
(while other suites remain uncorrected).

4. Fixed duplication of the have_file_key_management.inc and
have_filekeymanagement.inc files between different suites,
these checks are also transferred to the top level.

5. Added garbd presence check and garbd path variable.

https://jira.mariadb.org/browse/MDEV-18565

3 files changed, 138 insertions, 1 deletions

diff --git a/mysql-test/lib/My/SafeProcess.pm b/mysql-test/lib/My/SafeProcess.pm
index 19f2893ea51..87054019759 100644
--- a/mysql-test/lib/My/SafeProcess.pm
+++ b/mysql-test/lib/My/SafeProcess.pm
@@ -100,6 +100,8 @@ else
   $bindir = getcwd();
 }
 
+our $wsrep_check_version;
+
 # Find the safe process binary or script
 sub find_bin {
   if (IS_WIN32PERL or IS_CYGWIN)
@@ -119,6 +121,10 @@ sub find_bin {
 			 "my_safe_process");
     push(@safe_process_cmd, $exe);
   }
+  # Wsrep version check utility:
+  $wsrep_check_version=
+    my_find_bin($bindir, ["lib/My/SafeProcess", "My/SafeProcess"],
+                "wsrep_check_version", NOT_REQUIRED);
 }
 
 
diff --git a/mysql-test/lib/My/SafeProcess/CMakeLists.txt b/mysql-test/lib/My/SafeProcess/CMakeLists.txt
index a71f5d8ca36..4c3b62fa67e 100644
--- a/mysql-test/lib/My/SafeProcess/CMakeLists.txt
+++ b/mysql-test/lib/My/SafeProcess/CMakeLists.txt
@@ -14,7 +14,7 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1335 USA
 
 
- IF (WIN32)
+IF (WIN32)
   ADD_EXECUTABLE(my_safe_process safe_process_win.cc)
   ADD_EXECUTABLE(my_safe_kill safe_kill_win.cc)
   TARGET_LINK_LIBRARIES(my_safe_kill dbghelp psapi)
@@ -22,6 +22,11 @@ ELSE()
   ADD_EXECUTABLE(my_safe_process safe_process.cc)
 ENDIF()
 
+IF(WITH_WSREP)
+  ADD_EXECUTABLE(wsrep_check_version wsrep_check_version.c)
+  TARGET_LINK_LIBRARIES(wsrep_check_version ${LIBDL})
+ENDIF()
+
 IF(NOT INSTALL_MYSQLTESTDIR)
   RETURN()
 ENDIF()
@@ -32,6 +37,9 @@ SET(INSTALL_ARGS
 )
 
 INSTALL(TARGETS my_safe_process ${INSTALL_ARGS})
+IF(WITH_WSREP)
+  INSTALL(TARGETS wsrep_check_version ${INSTALL_ARGS})
+ENDIF()
 IF (WIN32)
   INSTALL(TARGETS my_safe_kill ${INSTALL_ARGS})
 ENDIF()
diff --git a/mysql-test/lib/My/SafeProcess/wsrep_check_version.c b/mysql-test/lib/My/SafeProcess/wsrep_check_version.c
new file mode 100644
index 00000000000..616548d4f2d
--- /dev/null
+++ b/mysql-test/lib/My/SafeProcess/wsrep_check_version.c
@@ -0,0 +1,123 @@
+/* Copyright (c) 2009, 2019, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef _WIN32
+#include <windows.h>
+#define dlsym(lib, name) GetProcAddress((HMODULE)lib, name)
+#define dlopen(libname, unused) LoadLibraryEx(libname, NULL, 0)
+#define dlclose(lib) FreeLibrary((HMODULE)lib)
+#elif defined(HAVE_DLFCN_H)
+#include <dlfcn.h>
+#else
+#define NO_DLL
+#endif
+
+#ifndef NO_DLL
+
+#include "../../../../wsrep-lib/wsrep-API/v26/wsrep_api.h"
+
+/**************************************************************************
+ * Library loader
+ **************************************************************************/
+
+static int wsrep_check_iface_version(const char *found, const char *iface_ver)
+{
+    if (strcmp(found, iface_ver)) {
+        return ERANGE;
+    }
+    return 0;
+}
+
+typedef int (*wsrep_loader_fun)(wsrep_t*);
+
+static wsrep_loader_fun wsrep_dlf(void *dlh, const char *sym)
+{
+    union {
+        wsrep_loader_fun dlfun;
+        void *obj;
+    } alias;
+    alias.obj = dlsym(dlh, sym);
+    return alias.dlfun;
+}
+
+static int wsrep_check_version_symbol(void *dlh)
+{
+    char** dlversion = NULL;
+    dlversion = (char**) dlsym(dlh, "wsrep_interface_version");
+    if (dlversion == NULL)
+        return EINVAL;
+    return wsrep_check_iface_version(*dlversion, WSREP_INTERFACE_VERSION);
+}
+
+static int wsrep_print_version(void *dlh)
+{
+    char** dlversion = NULL;
+    dlversion = (char**) dlsym(dlh, "wsrep_interface_version");
+    if (dlversion == NULL)
+        return EINVAL;
+    printf("found: %s, need: %s\n", *dlversion, WSREP_INTERFACE_VERSION);
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    int rc = EINVAL;
+    void *dlh;
+    wsrep_loader_fun dlfun;
+
+    if (!(dlh = dlopen(getenv("WSREP_PROVIDER"), RTLD_NOW | RTLD_LOCAL))) {
+       goto err;
+    }
+
+    if (!(dlfun = wsrep_dlf(dlh, "wsrep_loader"))) {
+       goto err;
+    }
+
+    if (argc < 2 || strcmp(argv[1], "-p")) {
+        rc = wsrep_check_version_symbol(dlh);
+    }
+    else {
+        rc = wsrep_print_version(dlh);
+    }
+
+err:
+    if (dlh) dlclose(dlh);
+
+    if (rc == 0)
+        return 0;
+    else if (rc == ERANGE)
+        return 2;
+    else
+        return 1;
+}
+
+#else
+
+int main(void)
+{
+    return 1;
+}
+
+#endif