Updates to how shards are discovered while the module is running

SHOW DATABASES now takes notice of the state of the backends
Added scripts for sharding test preparation and local port blocking

server/modules/routing/dbshard/test/CMakeLists.txt

@@ -1,5 +1,8 @@
 if(MYSQLCLIENT_FOUND AND BUILD_TESTS)
   add_executable(testdbshard testdbshard.c)
   target_link_libraries(testdbshard ${MYSQLCLIENT_LIBRARIES} ssl crypto dl z m rt pthread)
-  add_test(NAME DBShardTest COMMAND $<TARGET_FILE:testdbshard> ${TEST_HOST} 3000 ${TEST_USER} ${TEST_PASSWORD})
+  foreach(VAR RANGE 3000 3003)
+    execute_process(COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/prepare_shard.sh ${TEST_HOST} ${VAR} ${TEST_USER} ${TEST_PASSWORD})
+  endforeach()
+  add_test(NAME DBShardTest COMMAND $<TARGET_FILE:testdbshard> ${TEST_HOST} ${TEST_PORT_DB} ${TEST_USER} ${TEST_PASSWORD})
 endif()

server/modules/routing/dbshard/test/portblock.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+if [ $# -lt 1 ]
+then
+    echo "Usage $0 <port to block>"
+    exit 1
+fi
+sudo iptables -I INPUT 1 -i lo -p tcp --dport $1 -j DROP
+sudo iptables -I INPUT 1 -i lo -p tcp --sport $1 -j DROP
+echo "Traffic to port $1 blocked."

server/modules/routing/dbshard/test/prepare_shard.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+if [ $# -lt 3 ]
+then
+    echo "usage $0 <host> <port> <username> <password>"
+    exit 1
+fi
+HOST=$1
+PORT=$2
+USER=$3
+PW=$4
+SHD="shard$RANDOM"
+mysql -u $USER -p$PW -P $PORT -h $HOST -e "create database $SHD;"
+echo "Created database \"$SHD\" at $HOST:$PORT"

server/modules/routing/dbshard/test/testdbshard.c

@@ -39,6 +39,8 @@ int main(int argc, char** argv)
     password = strdup(argv[4]);
 	rval = 0;
 
+    printf("Connecting to %s:%d as %s/%s\n",host,port,username,password);
+    
 	if((server = mysql_init(NULL)) == NULL){
         fprintf(stderr,"Error : Initialization of MySQL client failed.\n");
 	    rval = 1;