MDEV-14578: mysql_install_db install unix_socket plugin when...

MDEV-14578: mysql_install_db install unix_socket plugin when --auth-root-authentication-method=socket

$ cmake -DPLUGIN_AUTH_SOCKET=STATIC ../mariadb-server-10.2/

$ scripts/mysql_install_db --datadir=/tmp/mysqldatadir-auth-static --auth-root-socket-user=dan --auth-root-authentication-method=socket --builddir=.  --srcdir=../mariadb-server-10.2
Installing MariaDB/MySQL system tables in '/tmp/mysqldatadir-auth-static' ...
OK

$ client/mysql -S /tmp/mysql.sock -e 'show create user dan@localhost'
+----------------------------------------------------------+
| CREATE USER for dan@localhost                            |
+----------------------------------------------------------+
| CREATE USER 'dan'@'localhost' IDENTIFIED VIA unix_socket |
+----------------------------------------------------------+

$ cmake -DPLUGIN_AUTH_SOCKET=NO ../mariadb-server-10.2/
$ scripts/mysql_install_db --datadir=/tmp/mysqldatadir-auth-none --auth-root-socket-user=dan --auth-root-authentication-method=socket --builddir=.  --srcdir=../mariadb-server-10.2
Installing MariaDB/MySQL system tables in '/tmp/mysqldatadir-auth-none' ...
ERROR: 1126  Can't open shared library '.../plugin/auth_socket/auth_socket.so' (errno: 2, cannot open shared object file: No such file or directory)
2018-05-01 11:38:56 0 [ERROR] Aborting

$ cmake -DPLUGIN_AUTH_SOCKET=DYNAMIC ../mariadb-server-10.2/
$ scripts/mysql_install_db --datadir=/tmp/mysqldatadir-auth-dyn --auth-root-socket-user=dan --auth-root-authentication-method=socket --builddir=.  --srcdir=../mariadb-server-10.2
Installing MariaDB/MySQL system tables in '/tmp/mysqldatadir-auth-dyn' ...
OK
$ ./sql/mysqld  --datadir=/tmp/mysqldatadir-auth-dyn  --lc-messages-dir=${PWD}/sql/share --plugin-dir=./plugin/auth_socket/
$ client/mysql -S /tmp/mysql.sock -e 'show create user dan@localhost'
+----------------------------------------------------------+
| CREATE USER for dan@localhost                            |
+----------------------------------------------------------+
| CREATE USER 'dan'@'localhost' IDENTIFIED VIA unix_socket |
+----------------------------------------------------------+

$ sudo make install
$ sudo chmod a+rwx /usr/local/mysql/data
$ cd /usr/local/mysql/
$ scripts/mysql_install_db  --auth-root-socket-user=dan --auth-root-authentication-method=socket
Installing MariaDB/MySQL system tables in './data' ...
OK
..
$ bin/mysqld_safe
$ client/mysql -S /tmp/mysql.sock -e 'show create user dan@localhost'
+----------------------------------------------------------+
| CREATE USER for dan@localhost                            |
+----------------------------------------------------------+
| CREATE USER 'dan'@'localhost' IDENTIFIED VIA unix_socket |
+----------------------------------------------------------+

Merges #767

scripts/mysql_install_db.sh

@@ -307,6 +307,7 @@ then
   langdir="$basedir/sql/share/english"
   srcpkgdatadir="$srcdir/scripts"
   buildpkgdatadir="$builddir/scripts"
+  plugindir="$builddir/plugin/auth_socket/"
 elif test -n "$basedir"
 then
   bindir="$basedir/bin" # only used in the help text
@@ -335,6 +336,7 @@ then
     cannot_find_file fill_help_tables.sql @pkgdata_locations@
     exit 1
   fi
+  plugindir="$basedir/@INSTALL_PLUGINDIR@"
 else
   basedir="@prefix@"
   bindir="@bindir@"
@@ -342,6 +344,7 @@ else
   mysqld="@libexecdir@/mysqld"
   srcpkgdatadir="@pkgdatadir@"
   buildpkgdatadir="@pkgdatadir@"
+  plugindir="@INSTALL_PLUGINDIR@"
 fi
 
 # Set up paths to SQL scripts required for bootstrap
@@ -460,6 +463,7 @@ mysqld_install_cmd_line()
 {
   "$mysqld_bootstrap" $defaults $defaults_group_suffix "$mysqld_opt" --bootstrap $silent_startup\
   "--basedir=$basedir" "--datadir=$ldata" --log-warnings=0 --enforce-storage-engine="" \
+  "--plugin-dir=${plugindir}" \
   $args --max_allowed_packet=8M \
   --net_buffer_length=16K
 }

scripts/mysql_system_tables_data.sql

@@ -46,8 +46,13 @@ INSERT INTO tmp_user_nopasswd VALUES ('localhost','root','','Y','Y','Y','Y','Y',
 REPLACE INTO tmp_user_nopasswd SELECT @current_hostname,'root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0,'','','N','N','',0 FROM dual WHERE @current_hostname != 'localhost';
 REPLACE INTO tmp_user_nopasswd VALUES ('127.0.0.1','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0,'','','N','N','',0);
 REPLACE INTO tmp_user_nopasswd VALUES ('::1','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0,'','','N','N', '', 0);
--- More secure root account using unix sucket auth.
+-- More secure root account using unix socket auth.
 INSERT INTO tmp_user_socket VALUES ('localhost',IFNULL(@auth_root_socket, 'root'),'','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0,'unix_socket','','N', 'N','', 0);
+-- Need aria support to lookup information_schema.plugins (result is tmptable)
+IF @auth_root_socket is not null THEN
+  IF exists (SELECT 1 FROM INFORMATION_SCHEMA.ENGINES WHERE engine = 'aria' AND support IN ('YES', 'DEFAULT', 'ENABLED')) THEN
+    IF not exists(select 1 from information_schema.plugins where plugin_name='unix_socket') THEN
+       INSTALL SONAME 'auth_socket'; END IF; END IF; END IF;
 -- Anonymous user with no privileges.
 INSERT INTO tmp_user_anonymous (host,user) VALUES ('localhost','');
 INSERT INTO tmp_user_anonymous (host,user) SELECT @current_hostname,'' FROM dual WHERE @current_hostname != 'localhost';