PT-1530 WIP Added encryption plugins to sandbox start

In order to be able to test encryption support in Percona Server and
MySQL, we need to enable encription plugins in the sandbox.
This commit adds detection of plugin libraries in the MySQL binaries
directory and enables it automatically.

sandbox/servers/start

@@ -51,32 +51,30 @@ echo -n "Starting MySQL test server on port PORT... "
 cwd=$PWD
 cd $BASEDIR
 
-plugins=""
-pluginsparam=""
-plugindirparam=""
+encryption_plugins=""
+plugins_dir_cmd=""
+
+plugins_cmd=""
+keyring_cmd=""
 
-echo "basedir $BASEDIR"
 if [ -e "${BASEDIR}/lib/mysql/plugin/keyring_file.so" ]; then
-     plugins="${BASEDIR}/lib/mysql/plugin/keyring_file.so"
-     plugindirparam="--plugin-dir=${BASEDIR}/lib/mysql/plugin/"
+     encryption_plugins="${BASEDIR}/lib/mysql/plugin/keyring_file.so"
 fi
 
-if [ ! -z "$plugins" ]; then
-    pluginsparam="--early-plugin-load"
+if [ ! -z "$encryption_plugins" ]; then
+    plugins_cmd="--early-plugin-load=${encryption_plugins}"
+    keyring_cmd="--keyring_file_data=/tmp/PORT/data/keyring"
+    plugins_dir_cmd="--plugin-dir=${BASEDIR}/lib/mysql/plugin/"
 fi
 
-echo "plugins: $plugins"
-echo "pluginsparam: $pluginsparam"
-
 init_file="/tmp/12345/mysql-init"
 if [ -e $init_file ]; then
-    $BASEDIR/bin/mysqld --defaults-file=/tmp/12345/my.sandbox.cnf -u root --init-file $init_file $pluginsparam &
+    $BASEDIR/bin/mysqld --defaults-file=/tmp/12345/my.sandbox.cnf -u root --init-file $init_file $plugins_cmd $plugins_dir_cmd $keyring_cmd &
 else
-    $BASEDIR/bin/mysqld --defaults-file=/tmp/12345/my.sandbox.cnf $pluginsparam $plugins $plugindirparam > /dev/null 2>&1 &
+    $BASEDIR/bin/mysqld --defaults-file=/tmp/12345/my.sandbox.cnf --keyring_file_data=/tmp/12345/data/keyring $plugins_cmd $plugins_dir_cmd $keyring_cmd > /dev/null 2>&1 &
 fi
 cd $PWD
 
-
 # Wait for MySQL to actually be up, i.e. to respond to queries.
 for i in $(_seq 60); do
    if sandbox_is_alive; then