Add flush_cache script. Closes #140

tools/flush_cache

@@ -0,0 +1,59 @@
+#!/usr/bin/env node
+
+var path = require('path');
+var request    = require('request');
+
+function usage(me, exitcode) {
+  console.log("Usage: " + me + " [--env <environment>] <username> <tablename>");
+  process.exit(exitcode);
+}
+
+var node_path = process.argv.shift(); 
+var script_path = process.argv.shift(); 
+var basedir = path.dirname(script_path);
+var me = path.basename(script_path);
+
+var ENV = 'development.js';
+var username, table;
+var arg;
+while ( arg = process.argv.shift() ) {
+  if ( arg == '--env' ) {
+    ENV = process.argv.shift();
+  }
+  else if ( ! username ) {
+    username = arg;
+  }
+  else if ( ! table ) {
+    table = arg;
+  }
+  else {
+    console.warn("Unused parameter " + arg);
+  }
+}
+
+if ( ! table ) {
+  usage(me, 1);
+}
+
+global.environment = require('../config/environments/' + ENV);
+
+// _after_ setting global.environment
+var serverOptions = require('../lib/cartodb/server_options');
+
+var host = global.environment.host;
+var port = global.environment.port;
+var re = ''+serverOptions.re_userFromHost;
+var hostname = re.replace(/^\/\^/, '')
+                 .replace(/\/$$/, '')
+                 .replace(/\\/g,'')
+                 .replace(/\([^)]*\)/,username)
+              ;
+//console.log("re: " + re);
+//console.log("hostname: " + hostname);
+
+var url = 'http://' + host + ':' + port + '/tiles/' + table + '/flush_cache';
+request.del({ url: url, headers: { host: hostname } },
+function(err, res, body) {
+  if ( err ) throw err;
+  console.log(res.body);
+});