mongodb copy indexes from one collection to another code example

Example: mongodb copy indexes from a server to another

db.getCollectionNames().forEach(function(collection) {
indexes = db[collection].getIndexes();
indexes.forEach(function (c) {
opt = ''
ixkey = JSON.stringify(c.key, null, 1).replace(/(\r\n|\n|\r)/gm,"")
ns = c.ns.substr(c.ns.indexOf(".") + 1, c.ns.length)
for (var key in c) {
 if (key != 'key' && key != 'ns' && key != 'v') {
 if (opt != '') { opt+= ','}        
 if (c.hasOwnProperty(key)) {
   if (typeof(c[key]) == "string") {
        opt +=  (key + ': "' + c[key] + '"')
      } else  {
        opt+=  (key + ": " + c[key])
       }
     }
   }
  }
  if (opt != '') { opt = '{' + opt + '}'}
  print ('db.' + ns + '.ensureIndex(' + ixkey + ','+  opt + ')')
 })});