RUST-1202 Sync latest initial DNS seedlist discovery tests (#595)

Author: kmahar

src/test/spec/initial_dns_seedlist_discovery.rs

@@ -15,12 +15,16 @@ use crate::{
 #[serde(deny_unknown_fields)]
 struct TestFile {
     uri: String,
-    seeds: Vec<String>,
-    hosts: Vec<String>,
+    seeds: Option<Vec<String>>,
+    hosts: Option<Vec<String>>,
     options: Option<ResolvedOptions>,
     parsed_options: Option<ParsedOptions>,
     error: Option<bool>,
     comment: Option<String>,
+    #[serde(rename = "numSeeds")]
+    num_seeds: Option<usize>,
+    #[serde(rename = "numHosts")]
+    num_hosts: Option<usize>,
 }
 
 #[derive(Debug, Deserialize, PartialEq)]
@@ -31,6 +35,8 @@ struct ResolvedOptions {
     ssl: bool,
     load_balanced: Option<bool>,
     direct_connection: Option<bool>,
+    srv_max_hosts: Option<u32>,
+    srv_service_name: Option<String>,
 }
 
 impl ResolvedOptions {
@@ -56,26 +62,25 @@ struct ParsedOptions {
 }
 
 async fn run_test(mut test_file: TestFile) {
-    // TODO DRIVERS-796: unskip this test
-    if test_file.uri == "mongodb+srv://test5.test.build.10gen.cc/?authSource=otherDB" {
-        log_uncaptured(
-            "skipping initial_dns_seedlist_discovery due to authSource being specified without \
-             credentials",
-        );
-        return;
-    }
+    if let Some(ref options) = test_file.options {
+        // TODO RUST-933: Remove this skip.
+        let skip = if options.srv_max_hosts.is_some() {
+            Some("srvMaxHosts")
+        // TODO RUST-911: Remove this skip.
+        } else if options.srv_service_name.is_some() {
+            Some("srvServiceName")
+        } else {
+            None
+        };
 
-    // TODO RUST-980 unskip these tests
-    if test_file
-        .options
-        .as_ref()
-        .and_then(|o| o.load_balanced)
-        .unwrap_or(false)
-    {
-        log_uncaptured(
-            "skipping initial_dns_seedlist_discovery due to load-balanced test configuration",
-        );
-        return;
+        if let Some(skip) = skip {
+            log_uncaptured(format!(
+                "skipping initial_dns_seedlist_discovery test case due to unsupported connection \
+                 string option: {}",
+                skip,
+            ));
+            return;
+        }
     }
 
     // "encoded-userinfo-and-db.json" specifies a database name with a question mark which is
@@ -104,38 +109,32 @@ async fn run_test(mut test_file: TestFile) {
 
     let options = result.unwrap();
 
-    let mut expected_seeds = test_file.seeds.split_off(0);
-    let mut actual_seeds = options
-        .hosts
-        .iter()
-        .map(|address| address.to_string())
-        .collect::<Vec<_>>();
+    if let Some(ref mut expected_seeds) = test_file.seeds {
+        let mut actual_seeds = options
+            .hosts
+            .iter()
+            .map(|address| address.to_string())
+            .collect::<Vec<_>>();
 
-    expected_seeds.sort();
-    actual_seeds.sort();
+        expected_seeds.sort();
+        actual_seeds.sort();
 
-    assert_eq!(expected_seeds, actual_seeds,);
+        assert_eq!(*expected_seeds, actual_seeds);
+        if let Some(expected_seed_count) = test_file.num_seeds {
+            assert_eq!(actual_seeds.len(), expected_seed_count)
+        }
+    }
 
     // "txt-record-with-overridden-ssl-option.json" requires SSL be disabled; see DRIVERS-1324.
     let requires_tls = match test_file.options {
         Some(ref options) => options.ssl,
         None => true,
     };
     let client = TestClient::new().await;
-    let skip = if !client.is_replica_set() {
-        Some("not replica set")
-    } else if client.options.repl_set_name.as_deref() != Some("repl0") {
-        Some("repl_set_name != repl0")
-    } else if requires_tls != client.options.tls_options().is_some() {
-        Some("tls requirement mismatch")
-    } else {
-        None
-    };
-    if let Some(skip) = skip {
-        log_uncaptured(format!(
-            "skipping initial_dns_seedlist_discovery due to topology ({})",
-            skip
-        ))
+    if requires_tls != client.options.tls_options().is_some() {
+        log_uncaptured(
+            "skipping initial_dns_seedlist_discovery test case due to TLS requirement mismatch",
+        )
     } else {
         // If the connection URI provides authentication information, manually create the user
         // before connecting.
@@ -169,7 +168,9 @@ async fn run_test(mut test_file: TestFile) {
             .await
             .unwrap();
 
-        test_file.hosts.sort();
+        if let Some(ref mut hosts) = test_file.hosts {
+            hosts.sort();
+        }
 
         // This loop allows for some time to allow SDAM to discover the desired topology
         // TODO: RUST-232 or RUST-585: use SDAM monitoring / channels / timeouts to improve
@@ -179,8 +180,14 @@ async fn run_test(mut test_file: TestFile) {
             let mut actual_hosts = client.get_hosts().await;
             actual_hosts.sort();
 
-            if actual_hosts == test_file.hosts {
-                break;
+            if let Some(ref expected_hosts) = test_file.hosts {
+                if actual_hosts == *expected_hosts {
+                    break;
+                }
+            } else if let Some(expected_host_count) = test_file.num_hosts {
+                if actual_hosts.len() == expected_host_count {
+                    break;
+                }
             } else if start.elapsed() > Duration::from_secs(5) {
                 panic!(
                     "expected to eventually discover {:?}, instead found {:?}",
@@ -219,16 +226,57 @@ async fn run_test(mut test_file: TestFile) {
 #[cfg_attr(feature = "async-std-runtime", async_std::test)]
 async fn replica_set() {
     let _guard: RwLockReadGuard<()> = LOCK.run_concurrently().await;
+    let client = TestClient::new().await;
+    let skip =
+        if client.is_replica_set() && client.options.repl_set_name.as_deref() != Some("repl0") {
+            Some("repl_set_name != repl0")
+        } else if !client.is_replica_set() {
+            Some("not a replica set")
+        } else {
+            None
+        };
+    if let Some(skip) = skip {
+        log_uncaptured(format!(
+            "skipping initial_dns_seedlist_discovery::replica_set due to unmet topology \
+             requirement ({})",
+            skip
+        ));
+        return;
+    }
+
     run_spec_test(&["initial-dns-seedlist-discovery", "replica-set"], run_test).await;
 }
 
 #[cfg_attr(feature = "tokio-runtime", tokio::test)]
 #[cfg_attr(feature = "async-std-runtime", async_std::test)]
 async fn load_balanced() {
     let _guard: RwLockReadGuard<()> = LOCK.run_concurrently().await;
+    let client = TestClient::new().await;
+    if !client.is_load_balanced() {
+        log_uncaptured(
+            "skipping initial_dns_seedlist_discovery::load_balanced due to unmet topology \
+             requirement (not a load balanced cluster)",
+        );
+        return;
+    }
     run_spec_test(
         &["initial-dns-seedlist-discovery", "load-balanced"],
         run_test,
     )
     .await;
 }
+
+#[cfg_attr(feature = "tokio-runtime", tokio::test)]
+#[cfg_attr(feature = "async-std-runtime", async_std::test)]
+async fn sharded() {
+    let _guard: RwLockReadGuard<()> = LOCK.run_concurrently().await;
+    let client = TestClient::new().await;
+    if !client.is_sharded() {
+        log_uncaptured(
+            "skipping initial_dns_seedlist_discovery::sharded due to unmet topology requirement \
+             (not a sharded cluster)",
+        );
+        return;
+    }
+    run_spec_test(&["initial-dns-seedlist-discovery", "sharded"], run_test).await;
+}

src/test/spec/json/initial-dns-seedlist-discovery/README.rst

@@ -10,11 +10,21 @@ Test Setup
 
 The tests in the ``replica-set`` directory MUST be executed against a
 three-node replica set on localhost ports 27017, 27018, and 27019 with
-replica set name ``repl0``. The tests in ``load-balanced`` MUST be executed
-against a load-balanced sharded cluster with the mongos servers running on
-localhost ports 27017 and 27018 and load balancers, shard servers, and config
-servers running on any open ports. In both cases, the clusters MUST be
-started with SSL enabled.
+replica set name ``repl0``.
+
+The tests in the ``load-balanced`` directory MUST be executed against a
+load-balanced sharded cluster with the mongos servers running on localhost ports
+27017 and 27018 and ``--loadBalancerPort`` 27050 and 27051, respectively
+(corresponding to the script in `drivers-evergreen-tools`_). The load balancers,
+shard servers, and config servers may run on any open ports.
+
+.. _`drivers-evergreen-tools`: https://github.com/mongodb-labs/drivers-evergreen-tools/blob/master/.evergreen/run-load-balancer.sh
+
+The tests in the ``sharded`` directory MUST be executed against a sharded
+cluster with the mongos servers running on localhost ports 27017 and 27018.
+Shard servers and config servers may run on any open ports.
+
+In all cases, the clusters MUST be started with SSL enabled.
 
 To run the tests that accompany this spec, you need to configure the SRV and
 TXT records with a real name server. The following records are required for
@@ -24,29 +34,32 @@ these tests::
   localhost.test.build.10gen.cc.            86400  IN A    127.0.0.1
   localhost.sub.test.build.10gen.cc.        86400  IN A    127.0.0.1
 
-  Record                                    TTL    Class   Port   Target
-  _mongodb._tcp.test1.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test1.test.build.10gen.cc.  86400  IN SRV  27018  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test2.test.build.10gen.cc.  86400  IN SRV  27018  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test2.test.build.10gen.cc.  86400  IN SRV  27019  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test3.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test5.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test6.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test7.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test8.test.build.10gen.cc.  86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test10.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test11.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test12.test.build.10gen.cc. 86400  IN SRV  27017  localhost.build.10gen.cc.
-  _mongodb._tcp.test13.test.build.10gen.cc. 86400  IN SRV  27017  test.build.10gen.cc.
-  _mongodb._tcp.test14.test.build.10gen.cc. 86400  IN SRV  27017  localhost.not-test.build.10gen.cc.
-  _mongodb._tcp.test15.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.not-build.10gen.cc.
-  _mongodb._tcp.test16.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.not-10gen.cc.
-  _mongodb._tcp.test17.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.not-cc.
-  _mongodb._tcp.test18.test.build.10gen.cc. 86400  IN SRV  27017  localhost.sub.test.build.10gen.cc.
-  _mongodb._tcp.test19.test.build.10gen.cc. 86400  IN SRV  27017  localhost.evil.build.10gen.cc.
-  _mongodb._tcp.test19.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test20.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.cc.
-  _mongodb._tcp.test21.test.build.10gen.cc. 86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  Record                                      TTL    Class   Port   Target
+  _mongodb._tcp.test1.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test1.test.build.10gen.cc.    86400  IN SRV  27018  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test2.test.build.10gen.cc.    86400  IN SRV  27018  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test2.test.build.10gen.cc.    86400  IN SRV  27019  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test3.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test5.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test6.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test7.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test8.test.build.10gen.cc.    86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test10.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test11.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test12.test.build.10gen.cc.   86400  IN SRV  27017  localhost.build.10gen.cc.
+  _mongodb._tcp.test13.test.build.10gen.cc.   86400  IN SRV  27017  test.build.10gen.cc.
+  _mongodb._tcp.test14.test.build.10gen.cc.   86400  IN SRV  27017  localhost.not-test.build.10gen.cc.
+  _mongodb._tcp.test15.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.not-build.10gen.cc.
+  _mongodb._tcp.test16.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.not-10gen.cc.
+  _mongodb._tcp.test17.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.not-cc.
+  _mongodb._tcp.test18.test.build.10gen.cc.   86400  IN SRV  27017  localhost.sub.test.build.10gen.cc.
+  _mongodb._tcp.test19.test.build.10gen.cc.   86400  IN SRV  27017  localhost.evil.build.10gen.cc.
+  _mongodb._tcp.test19.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test20.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test21.test.build.10gen.cc.   86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _customname._tcp.test22.test.build.10gen.cc 86400  IN SRV  27017  localhost.test.build.10gen.cc.
+  _mongodb._tcp.test23.test.build.10gen.cc.   86400  IN SRV  8000   localhost.test.build.10gen.cc.
+  _mongodb._tcp.test24.test.build.10gen.cc.   86400  IN SRV  8000   localhost.test.build.10gen.cc.
 
   Record                                    TTL    Class   Text
   test5.test.build.10gen.cc.                86400  IN TXT  "replicaSet=repl0&authSource=thisDB"
@@ -58,11 +71,18 @@ these tests::
   test11.test.build.10gen.cc.               86400  IN TXT  "replicaS" "et=rep" "l0"
   test20.test.build.10gen.cc.               86400  IN TXT  "loadBalanced=true"
   test21.test.build.10gen.cc.               86400  IN TXT  "loadBalanced=false"
+  test24.test.build.10gen.cc.               86400  IN TXT  "loadBalanced=true"
+
+Notes:
 
-Note that ``test4`` is omitted deliberately to test what happens with no SRV
-record. ``test9`` is missing because it was deleted during the development of
-the tests. The missing ``test.`` sub-domain in the SRV record target for
-``test12`` is deliberate.
+- ``test4`` is omitted deliberately to test what happens with no SRV record.
+- ``test9`` is missing because it was deleted during the development of the
+  tests.
+- The missing ``test.`` sub-domain in the SRV record target for ``test12`` is
+  deliberate.
+- ``test22`` is used to test a custom service name (``customname``).
+- ``test23`` and ``test24`` point to port 8000 (HAProxy) and are used for
+  load-balanced tests.
 
 In our tests we have used ``localhost.test.build.10gen.cc`` as the domain, and
 then configured ``localhost.test.build.10gen.cc`` to resolve to 127.0.0.1.
@@ -76,28 +96,49 @@ Test Format and Use
 
 These YAML and JSON files contain the following fields:
 
-- ``uri``: a mongodb+srv connection string
+- ``uri``: a ``mongodb+srv`` connection string
 - ``seeds``: the expected set of initial seeds discovered from the SRV record
+- ``numSeeds``: the expected number of initial seeds discovered from the SRV
+  record. This is mainly used to test ``srvMaxHosts``, since randomly selected
+  hosts cannot be deterministically asserted.
 - ``hosts``: the discovered topology's list of hosts once SDAM completes a scan
-- ``options``: the parsed connection string options as discovered from URI and
-  TXT records
-- ``parsed_options``: additional options present in the `Connection String`_
-  URI such as ``Userinfo`` (as ``user`` and ``password``), and ``Auth
-  database`` (as ``auth_database``).
+- ``numHosts``: the expected number of hosts discovered once SDAM completes a
+  scan. This is mainly used to test ``srvMaxHosts``, since randomly selected
+  hosts cannot be deterministically asserted.
+- ``options``: the parsed `URI options`_ as discovered from the
+  `Connection String`_'s "Connection Options" component and SRV resolution
+  (e.g. TXT records, implicit ``tls`` default).
+- ``parsed_options``: additional, parsed options from other `Connection String`_
+  components. This is mainly used for asserting ``UserInfo`` (as ``user`` and
+  ``password``) and ``Auth database`` (as ``auth_database``).
 - ``error``: indicates that the parsing of the URI, or the resolving or
   contents of the SRV or TXT records included errors.
 - ``comment``: a comment to indicate why a test would fail.
 
 .. _`Connection String`: ../../connection-string/connection-string-spec.rst
+.. _`URI options`: ../../uri-options/uri-options.rst
+
+For each file, create a MongoClient initialized with the ``mongodb+srv``
+connection string.
+
+If ``seeds`` is specified, drivers SHOULD verify that the set of hosts in the
+client's initial seedlist matches the list in ``seeds``. If ``numSeeds`` is
+specified, drivers SHOULD verify that the size of that set matches ``numSeeds``.
+
+If ``hosts`` is specified, drivers MUST verify that the set of
+ServerDescriptions in the client's TopologyDescription eventually matches the
+list in ``hosts``. If ``numHosts`` is specified, drivers MUST verify that the
+size of that set matches ``numHosts``.
+
+If ``options`` is specified, drivers MUST verify each of the values under
+``options`` match the MongoClient's parsed value for that option. There may be
+other options parsed by the MongoClient as well, which a test does not verify.
+
+If ``parsed_options`` is specified, drivers MUST verify that each of the values
+under ``parsed_options`` match the MongoClient's parsed value for that option.
+Supported values include, but are not limited to, ``user`` and ``password``
+(parsed from ``UserInfo``) and ``auth_database`` (parsed from
+``Auth database``).
 
-For each file, create MongoClient initialized with the mongodb+srv connection
-string. You SHOULD verify that the client's initial seed list matches the list of
-seeds. You MUST verify that the set of ServerDescriptions in the client's
-TopologyDescription eventually matches the list of hosts. You MUST verify that
-each of the values of the Connection String Options under ``options`` match the
-Client's parsed value for that option. There may be other options parsed by
-the Client as well, which a test does not verify. In ``uri-with-auth`` the URI
-contains a user/password set and additional options are provided in
-``parsed_options`` so that tests can verify authentication is maintained when
-evaluating URIs. You MUST verify that an error has been thrown if ``error`` is
-present.
+If ``error`` is specified and ``true``, drivers MUST verify that an error has
+been thrown.