Return a summarized list of all collection and index uris for a MongoDB cluster

getBackingFilenames.js

/**
 * getBackingFilenames(filter)
 *
 * Function to return a summarized list of all collections and indexes within all databases.
 * Passing *filter* will optionally filter the results by either the collection uri or
 * the uri of any of the indexes within a collection.
 *
 * @samples
 * // unfiltered
 * printjson(getBackingFilenames());
 *
 * // filtered
 * printjson(getBackingFilenames("index-69"));
 * [
 *     {
 *         "database" : "test",
 *         "collection" : "c_cards",
 *         "uri" : "statistics:table:collection-68-4608413808805359221",
 *         "indexes" : [
 *             {
 *                 "name" : "_id_",
 *                 "uri" : "statistics:table:index-69-4608413808805359221"
 *             }
 *         ]
 *     },
 *     {
 *         "database" : "test",
 *         "collection" : "routings",
 *         "uri" : "statistics:table:collection-68--2700007046186051335",
 *         "indexes" : [
 *             {
 *                 "name" : "_id_",
 *                 "uri" : "statistics:table:index-69--2700007046186051335"
 *             }
 *         ]
 *     }
 * ]
 *
 * @created 2020-03-23
 * @author  Alex Bevilacqua <[email protected]>
 * */

function getBackingFilenames(filter) {
  var results = [];
  // iterate over each database and collection
  db.getMongo().getDBNames().forEach(function(dbname) {
      db.getSiblingDB(dbname).getCollectionNames().forEach(function(c) {
         var coll = db.getSiblingDB(dbname).getCollection(c);
         // extract collection stats with index stats
         var s = coll.stats({ indexDetails: true });
         var result = { database: dbname, collection: c, uri: s.wiredTiger.uri, indexes: [] };
         var keys = Object.keys(s.indexDetails);
         for (var i = 0; i < keys.length; i++) {
             var idxUri = s.indexDetails[keys[i]].uri
             // if a filter was defined see if it matches any index backing files
             if (!filter || (filter && idxUri.includes(filter))) {
                 result.indexes.push({ name: keys[i], uri: idxUri });
             }
         }
         // if a filter was provided check if we have any indexes that matched, and if not see if the collection
         // uri matches
         if (!filter || result.indexes.length > 0 || result.uri.includes(filter)) {
             results.push(result);
         }
      });
  });
  return results;
}