SERVER-30086 better log message when using --port 0

1 files changed, 39 insertions, 0 deletions

diff --git a/jstests/noPassthrough/port_options.js b/jstests/noPassthrough/port_options.js
new file mode 100644
index 00000000000..6dbab50de61
--- /dev/null
+++ b/jstests/noPassthrough/port_options.js
@@ -0,0 +1,39 @@
+// Check --port= edge behaviors.
+
+(function() {
+    'use strict';
+    jsTest.log("Setting port=0 is okay unless binding to multiple IP interfaces.");
+
+    function runTest(bindIP, expectOk) {
+        jsTest.log("".concat("Testing with bindIP=[", bindIP, "], expectOk=[", expectOk, "]"));
+
+        const logpath = "".concat(MongoRunner.dataDir, "/mongod.log");
+
+        let pid = startMongoProgramNoConnect("mongod",
+                                             "--ipv6",
+                                             "--dbpath",
+                                             MongoRunner.dataDir,
+                                             "--logpath",
+                                             logpath,
+                                             "--bind_ip",
+                                             bindIP,
+                                             "--port",
+                                             0);
+        jsTest.log("".concat("pid=[", pid, "]"));
+
+        if (expectOk) {
+            const ec = stopMongoProgramByPid(pid);
+            const expect = _isWindows() ? 1 : -15;  // SIGTERM is 15
+            assert.eq(ec, expect, "Expected mongod terminate");
+        } else {
+            const ec = waitProgram(pid);
+            assert.eq(ec, MongoRunner.EXIT_NET_ERROR);
+            assert(
+                /Port 0 \(ephemeral port\) is not allowed when listening on multiple IP interfaces/
+                    .test(cat(logpath)),
+                "No warning issued for invalid port=0 usage");
+        }
+    }
+    runTest("127.0.0.1", true);
+    runTest("127.0.0.1,::1", false);
+}());