feat: add minimum changes for LB support (#1001)

Add a driver version that supports LB mode, and a hack to work around
existing known issues.

Also, as a drive-by fix, disable RHEL 8.0 s390x testing until the hosts
are more reliable.

Author: addaleax

.evergreen.yml

@@ -1544,9 +1544,8 @@ buildvariants:
     run_on: rhel72-zseries-small
     tasks:
       - name: e2e_tests_linux_s390x
-# TODO: reenable once /opt/mongodbtoolchain/v3 contains executables that
-# are actually compatible with the OS/architecture:
-# https://jira.mongodb.org/browse/BUILD-13551
+# TODO: Re-enable once RHEL 8.0 distros are ready for use
+# (see also pkg_smoke_tests_rhel80_s390x)
 #  - name: e2e_rhel80_s390x
 #    display_name: "RHEL 8.0 s390x (E2E Tests)"
 #    run_on: rhel80-zseries-small
@@ -1643,11 +1642,11 @@ buildvariants:
     run_on: rhel72-zseries-small
     tasks:
       - name: pkg_test_s390x_rpm
-  - name: pkg_smoke_tests_rhel80_s390x
-    display_name: "package smoke tests (RHEL 8.0 s390x)"
-    run_on: rhel80-zseries-small
-    tasks:
-      - name: pkg_test_s390x_rpm
+  #- name: pkg_smoke_tests_rhel80_s390x
+  #  display_name: "package smoke tests (RHEL 8.0 s390x)"
+  #  run_on: rhel80-zseries-small
+  #  tasks:
+  #    - name: pkg_test_s390x_rpm
   - name: pkg_smoke_tests_rhel81_ppc64le
     display_name: "package smoke tests (RHEL 8.1 ppc64le)"
     run_on: rhel81-power8-small

package-lock.json

@@ -119,7 +119,7 @@
     "karma-typescript": "^5.5.1",
     "lerna": "^4.0.0",
     "mocha": "^7.1.2",
-    "mongodb": "4.0.0-beta.6",
+    "mongodb": "addaleax/node-mongodb-native#71d4c39e5c858f49d10e840df626eca4da653e28",
     "mongodb-download-url": "^1.0.1",
     "mongodb-js-precommit": "^2.0.0",
     "nock": "^13.0.11",

package.json

@@ -30,7 +30,7 @@
     "@mongosh/errors": "0.0.0-dev.0",
     "@mongosh/i18n": "0.0.0-dev.0",
     "bson": "^4.4.1",
-    "mongodb": "4.0.0-beta.6",
+    "mongodb": "addaleax/node-mongodb-native#71d4c39e5c858f49d10e840df626eca4da653e28",
     "mongodb-build-info": "^1.2.0",
     "mongodb-connection-string-url": "^1.0.0"
   },

packages/service-provider-core/package-lock.json

@@ -42,7 +42,7 @@
     "@mongosh/service-provider-core": "0.0.0-dev.0",
     "@mongosh/types": "0.0.0-dev.0",
     "@types/sinon-chai": "^3.2.3",
-    "mongodb": "4.0.0-beta.6",
+    "mongodb": "addaleax/node-mongodb-native#71d4c39e5c858f49d10e840df626eca4da653e28",
     "saslprep": "mongodb-js/saslprep#v1.0.4",
     "mongodb-connection-string-url": "^1.0.0"
   },

packages/service-provider-core/package.json

@@ -284,6 +284,15 @@ export async function connectMongoClient(uri: string, clientOptions: MongoClient
     }
   }
   uri = await resolveMongodbSrv(uri, bus);
+  if (uri.startsWith('mongodb://') || uri.startsWith('mongodb+srv://')) {
+    // Hack for Load Balancer support until the driver side is finished:
+    const cs = new ConnectionString(uri);
+    if (cs.searchParams.get('loadBalanced') === 'true' &&
+        !cs.searchParams.has('maxPoolSize')) {
+      cs.searchParams.set('maxPoolSize', '1');
+      uri = cs.href;
+    }
+  }
   const client = new MClient(uri, clientOptions);
   await connectWithFailFast(client, bus);
   return client;