Fix RUBY-2023 mmap/mlaunch evergreen configurations hardcode server version (#1581)

* Fix RUBY-2023 mmap/mlaunch evergreen configurations hardcode server version

* Wait for sessions to work in 3.6 sharded clusters

* Try to work around server segfaults

* python

Author: p-mongo

.evergreen/functions.sh

@@ -186,6 +186,12 @@ prepare_server() {
   version=$2
 
   url=http://downloads.10gen.com/linux/mongodb-linux-x86_64-enterprise-$arch-$version.tgz
+  prepare_server_from_url $url
+}
+
+prepare_server_from_url() {
+  url=$1
+
   mongodb_dir="$MONGO_ORCHESTRATION_HOME"/mdb
   mkdir -p "$mongodb_dir"
   curl --retry 3 $url |tar xz -C "$mongodb_dir" -f -

.evergreen/run-tests-mlaunch.sh

@@ -23,9 +23,27 @@ setup_ruby
 
 install_deps
 
-arch=ubuntu1404
-version=4.0.9
-prepare_server $arch $version
+arch=`host_arch`
+
+desired_version=$MONGODB_VERSION
+if test -n "$MMAPV1" && test "$desired_version" = 4.0; then
+  # 4.0.13 segfaults on mmapv1 - https://jira.mongodb.org/browse/SERVER-43079
+  prepare_server $arch 4.0.9
+else
+  prog=`cat <<-EOT
+import urllib, json
+url = 'http://downloads.mongodb.org/current.json'
+info = json.load(urllib.urlopen(url))
+info = [i for i in info['versions'] if i['version'].startswith('$MONGODB_VERSION')][0]
+info = [i for i in info['downloads'] if i['archive']['url'].find('enterprise-$arch') > 0][0]
+url = info['archive']['url']
+print(url)
+EOT`
+
+  url=`python -c "$prog"`
+
+  prepare_server_from_url $url
+fi
 
 install_mlaunch
 
@@ -58,6 +76,12 @@ bundle --version
 export MONGODB_URI="mongodb://localhost:27017/?serverSelectionTimeoutMS=30000$uri_options"
 bundle exec rake spec:prepare
 
+if test "$TOPOLOGY" = sharded_cluster && test $MONGODB_VERSION = 3.6; then
+  # On 3.6 server the sessions collection is not immediately available,
+  # wait for it to spring into existence
+  bundle exec rake spec:wait_for_sessions
+fi
+
 export MONGODB_URI="mongodb://localhost:27017/?appName=test-suite$uri_options"
 bundle exec rake spec:ci
 test_status=$?

Rakefile

@@ -34,6 +34,30 @@ namespace :spec do
     SpecSetup.new.run
   end
 
+  desc 'Waits for sessions to be available in the deployment'
+  task :wait_for_sessions do
+    $: << File.join(File.dirname(__FILE__), 'spec')
+
+    require 'support/utils'
+    require 'support/spec_config'
+    require 'support/client_registry'
+
+    client = ClientRegistry.instance.global_client('authorized')
+    client.database.command(ping: 1)
+    deadline = Time.now + 300
+    while Time.now < deadline
+      if client.cluster.send(:sessions_supported?)
+        break
+      end
+      sleep 1
+      client.close
+      client.reconnect
+    end
+    unless client.cluster.send(:sessions_supported?)
+      raise "Sessions did not become supported in the allowed time"
+    end
+  end
+
   desc 'Prints configuration used by the test suite'
   task :config do
     $: << File.join(File.dirname(__FILE__), 'spec')