bugfix: S3C-2006 fix crash in vault-md on listing

Listed entries may either be objects { value[, key] } or plain strings
for key-only listings. Fix this by checking the filtered entry type
before calling trimMetadata().

lib/algos/list/Extension.js

@@ -2,6 +2,23 @@
 
 const { FILTER_SKIP, SKIP_NONE } = require('./tools');
 
+// Use a heuristic to amortize the cost of JSON
+// serialization/deserialization only on largest metadata where the
+// potential for size reduction is high, considering the bulk of the
+// blob size is due to the "location" field containing a large number
+// of MPU parts.
+//
+// Measured on some standard metadata:
+// - 100 parts -> 9K blob
+// - 2000 parts -> 170K blob
+//
+// Using a 10K threshold should lead to a worst case of about 10M to
+// store a raw listing of 1000 entries, even with some growth
+// multiplication factor due to some internal memory duplication, it
+// should stay within reasonable memory limits.
+
+const TRIM_METADATA_MIN_BLOB_SIZE = 10000;
+
 /**
  *  Base class of listing extensions.
  */
@@ -23,6 +40,38 @@ class Extension {
         this.keys = 0;
     }
 
+    /**
+     * Filters-out non-requested optional fields from the value. This function
+     * shall be applied on any value that is to be returned as part of the
+     * result of a listing extension.
+     *
+     * @param {String} value - The JSON value of a listing item
+     *
+     * @return {String} The value that may have been trimmed of some
+     * heavy unused fields, or left untouched (depending on size
+     * heuristics)
+     */
+    trimMetadata(value) {
+        let ret = undefined;
+        if (value.length >= TRIM_METADATA_MIN_BLOB_SIZE) {
+            try {
+                ret = JSON.parse(value);
+                delete ret.location;
+                ret = JSON.stringify(ret);
+            } catch (e) {
+                // Prefer returning an unfiltered data rather than
+                // stopping the service in case of parsing failure.
+                // The risk of this approach is a potential
+                // reproduction of MD-692, where too much memory is
+                // used by repd.
+                this.logger.warn(
+                    'Could not parse Object Metadata while listing',
+                    { err: e.toString() });
+            }
+        }
+        return ret || value;
+    }
+
     /**
      * Generates listing parameters that metadata can understand from the input
      * parameters. What metadata can understand: gt, gte, lt, lte, limit, keys,

lib/algos/list/basic.js

@@ -56,7 +56,14 @@ class List extends Extension {
         if (this.keys >= this.maxKeys) {
             return FILTER_END;
         }
-        this.res.push(elem);
+        if (typeof elem === 'object') {
+            this.res.push({
+                key: elem.key,
+                value: this.trimMetadata(elem.value),
+            });
+        } else {
+            this.res.push(elem);
+        }
         this.keys++;
         return FILTER_ACCEPT;
     }

lib/algos/list/delimiter.js

@@ -60,9 +60,11 @@ class Delimiter extends Extension {
      * @param {Boolean} [parameters.alphabeticalOrder] - Either the result is
      *                                                   alphabetically ordered
      *                                                   or not
+     * @param {RequestLogger} logger                   - The logger of the
+     *                                                   request
      */
-    constructor(parameters) {
-        super(parameters);
+    constructor(parameters, logger) {
+        super(parameters, logger);
         // original listing parameters
         this.delimiter = parameters.delimiter;
         this.prefix = parameters.prefix;
@@ -142,7 +144,7 @@ class Delimiter extends Extension {
         if (this._reachedMaxKeys()) {
             return FILTER_END;
         }
-        this.Contents.push({ key, value });
+        this.Contents.push({ key, value: this.trimMetadata(value) });
         this[this.nextContinueMarker] = key;
         ++this.keys;
         return FILTER_ACCEPT;

lib/algos/list/delimiterMaster.js

@@ -22,9 +22,10 @@ class DelimiterMaster extends Delimiter {
      * @param {Boolean} parameters.v2         - indicates whether v2 format
      * @param {String}  parameters.startAfter - marker per amazon v2 format
      * @param {String}  parameters.continuationToken - obfuscated amazon token
+     * @param {RequestLogger} logger          - The logger of the request
      */
-    constructor(parameters) {
-        super(parameters);
+    constructor(parameters, logger) {
+        super(parameters, logger);
         // non-PHD master version or a version whose master is a PHD version
         this.prvKey = undefined;
         this.prvPHDKey = undefined;

lib/algos/list/delimiterVersions.js

@@ -25,8 +25,8 @@ function formatVersionKey(key, versionId) {
  * @prop {Number} maxKeys              - number of keys to list
  */
 class DelimiterVersions extends Delimiter {
-    constructor(parameters) {
-        super(parameters);
+    constructor(parameters, logger) {
+        super(parameters, logger);
         // specific to version listing
         this.keyMarker = parameters.keyMarker;
         this.versionIdMarker = parameters.versionIdMarker;
@@ -75,7 +75,11 @@ class DelimiterVersions extends Delimiter {
         if (this._reachedMaxKeys()) {
             return FILTER_END;
         }
-        this.Contents.push(obj);
+        this.Contents.push({
+            key: obj.key,
+            value: this.trimMetadata(obj.value),
+            versionId: obj.versionId,
+        });
         this.NextMarker = obj.key;
         this.NextVersionIdMarker = obj.versionId;
         ++this.keys;

package.json

@@ -33,7 +33,7 @@
     "socket.io-client": "~1.7.3",
     "utf8": "2.1.2",
     "uuid": "^3.0.1",
-    "werelogs": "scality/werelogs#0ff7ec82",
+    "werelogs": "scality/werelogs#hotfix/7.4.2",
     "xml2js": "~0.4.16"
   },
   "optionalDependencies": {
@@ -43,7 +43,7 @@
     "eslint": "2.13.1",
     "eslint-plugin-react": "^4.3.0",
     "eslint-config-airbnb": "6.2.0",
-    "eslint-config-scality": "scality/Guidelines#71a059ad",
+    "eslint-config-scality": "scality/Guidelines#hotfix/7.4.2",
     "lolex": "1.5.2",
     "mocha": "2.5.3",
     "temp": "0.8.3"

tests/unit/algos/list/basic.js

@@ -17,9 +17,11 @@ class Test {
 describe('Basic listing algorithm', () => {
     const data = [];
     for (let i = 0; i < 15000; ++i) {
+        // Following the fix for S3C-1985, data is set as a stringified JSON
+        // object, so that the test does not keep logging warnings.
         data.push({
             key: `key${i}`,
-            value: `value${i}`,
+            value: `{"data":"value${i}"}`,
         });
     }
     const tests = [
@@ -38,4 +40,29 @@ describe('Basic listing algorithm', () => {
             done();
         });
     });
+
+    it('Should support entries with no key', () => {
+        const res1 = performListing([{
+            value: '{"data":"foo"}',
+        }], Basic, { maxKeys: 1 }, logger);
+        assert.deepStrictEqual(res1, [{
+            key: undefined,
+            value: '{"data":"foo"}',
+        }]);
+
+        const res2 = performListing([{
+            key: undefined,
+            value: '{"data":"foo"}',
+        }], Basic, { maxKeys: 1 }, logger);
+        assert.deepStrictEqual(res2, [{
+            key: undefined,
+            value: '{"data":"foo"}',
+        }]);
+    });
+
+    it('Should support key-only listing', () => {
+        const res = performListing(['key1', 'key2'],
+                                   Basic, { maxKeys: 1 }, logger);
+        assert.deepStrictEqual(res, ['key1']);
+    });
 });

tests/unit/algos/list/delimiterMaster.js

@@ -24,11 +24,19 @@ const EmptyResult = {
     Delimiter: undefined,
 };
 
+const fakeLogger = {
+    trace: () => {},
+    debug: () => {},
+    info: () => {},
+    warn: () => {},
+    error: () => {},
+    fatal: () => {},
+};
 
 describe('Delimiter All masters listing algorithm', () => {
     it('should return SKIP_NONE for DelimiterMaster when both NextMarker ' +
        'and NextContinuationToken are undefined', () => {
-        const delimiter = new DelimiterMaster({ delimiter: '/' });
+        const delimiter = new DelimiterMaster({ delimiter: '/' }, fakeLogger);
 
         assert.strictEqual(delimiter.NextMarker, undefined);
 
@@ -40,7 +48,8 @@ describe('Delimiter All masters listing algorithm', () => {
     it('should return <key><VersionIdSeparator> for DelimiterMaster when ' +
        'NextMarker is set and there is a delimiter', () => {
         const key = 'key';
-        const delimiter = new DelimiterMaster({ delimiter: '/', marker: key });
+        const delimiter = new DelimiterMaster({ delimiter: '/', marker: key },
+                                             fakeLogger);
 
         /* Filter a master version to set NextMarker. */
         // TODO: useless once S3C-1628 is fixed.
@@ -57,7 +66,8 @@ describe('Delimiter All masters listing algorithm', () => {
        'NextContinuationToken is set and there is a delimiter', () => {
         const key = 'key';
         const delimiter = new DelimiterMaster(
-            { delimiter: '/', startAfter: key, v2: true });
+            { delimiter: '/', startAfter: key, v2: true },
+            fakeLogger);
 
         // Filter a master version to set NextContinuationToken
         delimiter.filter({ key, value: '' });
@@ -73,7 +83,7 @@ describe('Delimiter All masters listing algorithm', () => {
         const delimiter = new DelimiterMaster({
             delimiter: delimiterChar,
             marker: keyWithEndingDelimiter,
-        });
+        }, fakeLogger);
 
         /* When a delimiter is set and the NextMarker ends with the
          * delimiter it should return the next marker value. */
@@ -82,7 +92,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should skip entries not starting with prefix', () => {
-        const delimiter = new DelimiterMaster({ prefix: 'prefix' });
+        const delimiter = new DelimiterMaster({ prefix: 'prefix' }, fakeLogger);
 
         assert.strictEqual(delimiter.filter({ key: 'wrong' }), FILTER_SKIP);
         assert.strictEqual(delimiter.NextMarker, undefined);
@@ -91,7 +101,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should skip entries superior to next marker', () => {
-        const delimiter = new DelimiterMaster({ marker: 'b' });
+        const delimiter = new DelimiterMaster({ marker: 'b' }, fakeLogger);
 
         assert.strictEqual(delimiter.filter({ key: 'a' }), FILTER_SKIP);
         assert.strictEqual(delimiter.NextMarker, 'b');
@@ -100,7 +110,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a master version', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const key = 'key';
         const value = '';
 
@@ -117,7 +127,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a PHD version as first input', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const keyPHD = 'keyPHD';
         const objPHD = {
             key: keyPHD,
@@ -134,7 +144,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a PHD version', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const key = 'keyA';
         const value = '';
         const keyPHD = 'keyBPHD';
@@ -163,7 +173,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a version after a PHD', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const masterKey = 'key';
         const keyVersion = `${masterKey}${VID_SEP}version`;
         const value = '';
@@ -193,7 +203,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a delete marker', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const version = new Version({ isDeleteMarker: true });
         const key = 'key';
         const obj = {
@@ -210,7 +220,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should skip version after a delete marker', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const version = new Version({ isDeleteMarker: true });
         const key = 'key';
         const versionKey = `${key}${VID_SEP}version`;
@@ -226,7 +236,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept a new key after a delete marker', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const version = new Version({ isDeleteMarker: true });
         const key1 = 'key1';
         const key2 = 'key2';
@@ -249,7 +259,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should accept the master version and skip the other ones', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const masterKey = 'key';
         const masterValue = 'value';
         const versionKey = `${masterKey}${VID_SEP}version`;
@@ -277,7 +287,7 @@ describe('Delimiter All masters listing algorithm', () => {
     });
 
     it('should return good listing result for version', () => {
-        const delimiter = new DelimiterMaster({});
+        const delimiter = new DelimiterMaster({}, fakeLogger);
         const masterKey = 'key';
         const versionKey1 = `${masterKey}${VID_SEP}version1`;
         const versionKey2 = `${masterKey}${VID_SEP}version2`;
@@ -320,7 +330,8 @@ describe('Delimiter All masters listing algorithm', () => {
            const prefix2Key1 = `${commonPrefix2}key1`;
            const value = 'value';
 
-           const delimiter = new DelimiterMaster({ delimiter: delimiterChar });
+           const delimiter = new DelimiterMaster({ delimiter: delimiterChar },
+                                                 fakeLogger);
 
            /* Filter the first entry with a common prefix. It should be
             * accepted and added to the result. */
@@ -373,7 +384,8 @@ describe('Delimiter All masters listing algorithm', () => {
         const prefix2VersionKey1 = `${commonPrefix2}key1${VID_SEP}version`;
         const value = 'value';
 
-        const delimiter = new DelimiterMaster({ delimiter: delimiterChar });
+        const delimiter = new DelimiterMaster({ delimiter: delimiterChar },
+                                              fakeLogger);
 
         /* Filter the two first entries with the same common prefix to add
          * it to the result and reach the state where an entry is skipped
@@ -404,7 +416,8 @@ describe('Delimiter All masters listing algorithm', () => {
         const key = `${commonPrefix}key${VID_SEP}version`;
         const value = 'value';
 
-        const delimiter = new DelimiterMaster({ delimiter: delimiterChar });
+        const delimiter = new DelimiterMaster({ delimiter: delimiterChar },
+                                              fakeLogger);
         /* TODO: should be set to a whole key instead of just a common prefix
          * once ZENKO-1048 is fixed. */
         delimiter.NextMarker = commonPrefix;