Added configurable executable file directory

This allows MaxScale to launch processes from the directory where
the `maxscale` executable is located.

Documentation/Getting-Started/Configuration-Guide.md

@@ -281,6 +281,14 @@ Configure the directory for the PID file for MaxScale. This file contains the Pr
 piddir=/tmp/maxscale_cache/
 ```
 
+#### `execdir`
+
+Configure the directory where the executable files reside. All internal processes which are launched will use this directory to look for executable files.
+
+```
+execdir=/usr/local/bin/
+```
+
 #### `language`
 
 Set the folder where the errmsg.sys file is located in. MaxScale will look for the errmsg.sys file installed with MaxScale from this folder.

Documentation/Tutorials/Administration-Tutorial.md

@@ -27,26 +27,7 @@ or
 ```
 It is also possible to start MaxScale by executing the maxscale command itself. Running the executable /usr/bin/maxscale will result in MaxScale running as a daemon process, unattached to the terminal in which it was started and using configuration files that it finds in the /etc directory.
 
-Options may be passed to the MaxScale binary that alter this default behavior, this options are documented in the table below.
-
-Switch|Long Option|Description
-------|-----------|-----------
-`-d`|`--nodaemon`|enable running in terminal process (default:disabled)
-`-f FILE`|`--config=FILE`|relative or absolute pathname of MaxScale configuration file (default:/etc/maxscale.cnf)
-`-l[file shm]`|`--log=[file shm]`|log to file or shared memory (default: file)
-`-L PATH`|`--logdir=PATH`|path to log file directory (default: /var/log/maxscale)
-`-D PATH`|`--datadir=PATH`|path to data directory, stored embedded mysql tables (default: /var/cache/maxscale)
-`-C PATH`|`--configdir=PATH`|path to configuration file directory (default: /etc/)
-`-B PATH`|`--libdir=PATH`|path to module directory (default: /usr/lib64/maxscale)
-`-A PATH`|`--cachedir=PATH`|path to cache directory (default: /var/cache/maxscale)
-`P PATH`|`--piddir=PATH`|PID file directory
-`-U USER`|`--user=USER`|run MaxScale as another user. The user ID and group ID of this user are used to run MaxScale.
-`-s [yes no]`|`--syslog=[yes no]`|log messages to syslog (default:yes)
-`-S [yes no]`|`--maxlog=[yes no]`|log messages to MaxScale log (default: yes)
-`-G [0 1]`|`--log_augmentation=[0 1]`|augment messages with the name of the function where the message was logged (default: 0). Primarily for development purposes.
-`-v`|`--version`|print version info and exit
-`-V`|`--version-full`|print version info and the commit ID the binary was built from
-`-?`|`--help`|show this help
+Options may be passed to the MaxScale binary that alter this default behavior. For a full list of all parameters, refer to the MaxScale help output by executing `maxscale --help`.
 
 Additional command line arguments can be passed to MaxScale with a configuration file placed at `/etc/sysconfig/maxscale` on RPM installations and `/etc/default/maxscale` file on DEB installations. Set the arguments in a variable called `MAXSCALE_OPTIONS` and remember to surround the arguments with quotes. The file should only contain environment variable declarations.
 

Documentation/maxscale.1

@@ -44,6 +44,9 @@ Path to cache directory. This is where MaxScale stores cached authentication dat
 .BR -P " \fIPATH\fB, --piddir=\fIPATH\fB"
 Location of MaxScale's PID file.
 .TP
+.BR -E " \fIPATH\fB, --execdir=\fIPATH\fB"
+Location of the executable files. When internal processes are launched from within MaxScale the binaries are assumed to be in this directory. If you have a custom location for binary executable files you need to add this parameter.
+.TP
 .BR -U " \fIUSER\fB, --user=\fIUSER\fB"
 Run MaxScale as another user. The user ID and group ID of this user are used to run MaxScale.
 .TP

query_classifier/qc_pp/qc_pp.c

@@ -22,11 +22,11 @@
  *
  */
 
-#include <sys/auxv.h>
 #include <elf.h>
 #include <log_manager.h>
 #include <modules.h>
 #include <query_classifier.h>
+#include <gwdirs.h>
 
 //#define QC_TRACE_ENABLED
 #undef QC_TRACE_ENABLED
@@ -88,28 +88,14 @@ static void end_and_unload_classifier(QUERY_CLASSIFIER* classifier, const char*
 static bool resolve_pp_path(char* path, int size)
 {
     bool success = false;
-    const char* exe_path = (const char*) getauxval(AT_EXECFN);
+    const char* exe_path = (const char*) get_execdir();
     size_t len = strlen(exe_path);
 
     if (len < size)
     {
+        /** get_execdir will always return a cleaned up version of
+         * the executable path */
         strcpy(path, exe_path);
-        char* s = path + len;
-
-        // Find the last '/'.
-        while ((*s != '/') && (s != path))
-        {
-            --s;
-            --len;
-        }
-
-        if (*s == '/')
-        {
-            ++s;
-            ++len;
-        }
-
-        *s = 0;
 
         int required_size = len + sizeof(MAXPP) + 1;
 

server/core/gateway.c

@@ -939,6 +939,8 @@ static void usage(void)
             "  -C, --configdir=PATH       path to configuration file directory (default: /etc/)\n"
             "  -D, --datadir=PATH         path to data directory, stored embedded mysql tables\n"
             "                             (default: /var/cache/maxscale)\n"
+            "  -E, --execdir=PATH         path to the maxscale and other executable files\n"
+            "                             (default: /usr/bin)\n"
             "  -N, --language=PATH         path to errmsg.sys file (default: /var/lib/maxscale)\n"
             "  -P, --piddir=PATH          path to PID file directory (default: /var/run/maxscale)\n"
             "  -U, --user=USER            run MaxScale as another user.\n"
@@ -1271,7 +1273,7 @@ int main(int argc, char **argv)
         }
     }
 
-    while ((opt = getopt_long(argc, argv, "dc:f:l:vVs:S:?L:D:C:B:U:A:P:G:N:",
+    while ((opt = getopt_long(argc, argv, "dc:f:l:vVs:S:?L:D:C:B:U:A:P:G:N:E:",
                               long_options, &option_index)) != -1)
     {
         bool succp = true;
@@ -1404,6 +1406,18 @@ int main(int argc, char **argv)
                 succp = false;
             }
             break;
+
+        case 'E':
+            if (handle_path_arg(&tmp_path, optarg, NULL, true, false))
+            {
+                set_execdir(tmp_path);
+            }
+            else
+            {
+                succp = false;
+            }
+            break;
+
         case 'S':
         {
             char* tok = strstr(optarg, "=");
@@ -2294,7 +2308,7 @@ void set_log_augmentation(const char* value)
 }
 
 /**
- * Pre-parse the MaxScale.cnf for config, log and module directories.
+ * Pre-parse the configuration file for various directory paths.
  * @param data Parameter passed by inih
  * @param section Section name
  * @param name Parameter name
@@ -2396,6 +2410,20 @@ static int cnf_preparser(void* data, const char* section, const char* name, cons
                 }
             }
         }
+        else if (strcmp(name, "execdir") == 0)
+        {
+            if (strcmp(get_execdir(), default_execdir) == 0)
+            {
+                if (handle_path_arg((char**)&tmp, (char*)value, NULL, true, false))
+                {
+                    set_execdir(tmp);
+                }
+                else
+                {
+                    return 0;
+                }
+            }
+        }
         else if (strcmp(name, "syslog") == 0)
         {
             if (!syslog_configured)

server/core/gwdirs.c

@@ -96,6 +96,18 @@ void set_libdir(char* param)
     libdir = param;
 }
 
+/**
+ * Set the executable directory. Internal processes will look for executables
+ * from here.
+ * @param str Path to directory
+ */
+void set_execdir(char* param)
+{
+    free(execdir);
+    clean_up_pathname(param);
+    execdir = param;
+}
+
 /**
  * Get the directory with all the modules.
  * @return The module directory
@@ -158,3 +170,12 @@ char* get_langdir()
 {
     return langdir ? langdir : (char*) default_langdir;
 }
+
+/**
+ * Get the directory with the executables.
+ * @return The executables directory
+ */
+char* get_execdir()
+{
+    return execdir ? execdir : (char*) default_execdir;
+}

server/include/gwdirs.h.in

@@ -39,6 +39,7 @@ static const char* default_datadir = "@MAXSCALE_VARDIR@/lib/maxscale/data";
 static const char* default_libdir = "@CMAKE_INSTALL_PREFIX@/@MAXSCALE_LIBDIR@";
 static const char* default_cachedir = "@MAXSCALE_VARDIR@/cache/maxscale";
 static const char* default_langdir = "@MAXSCALE_VARDIR@/lib/maxscale";
+static const char* default_execdir = "@CMAKE_INSTALL_PREFIX@/@MAXSCALE_BINDIR@";
 
 static char* configdir = NULL;
 static char* logdir = NULL;
@@ -47,6 +48,7 @@ static char* cachedir = NULL;
 static char* maxscaledatadir = NULL;
 static char* langdir = NULL;
 static char* piddir = NULL;
+static char* execdir = NULL;
 
 void set_libdir(char* param);
 void set_datadir(char* param);
@@ -55,6 +57,7 @@ void set_configdir(char* param);
 void set_logdir(char* param);
 void set_langdir(char* param);
 void set_piddir(char* param);
+void set_execdir(char* param);
 char* get_libdir();
 char* get_datadir();
 char* get_cachedir();
@@ -62,6 +65,7 @@ char* get_configdir();
 char* get_piddir();
 char* get_logdir();
 char* get_langdir();
+char* get_execdir();
 
 EXTERN_C_BLOCK_END