Server version-dependent argument processing is problematic

[p-mongo]

mlaunch conditionally defines which options it supports based on server version that it is launching. Specifically it either uses tls names or ssl names.

This is problematic when mlaunch is used to launch various server versions, because it obligates mlaunch's clients to conditionally formulate arguments to mlaunch when mlaunch is aware of both types of arguments.

Worse, mlaunch simply ignores the ssl arguments which causes it to misbehave, specifically it launches deployment with wrong configuration:

[2022-05-17 18:39:02.104] + python3 -m mtools.mlaunch.mlaunch --dir /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/db --binarypath /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin --setParameter enableTestCommands=1 --setParameter diagnosticDataCollectionEnabled=false --single --sslMode requireSSL --sslPEMKeyFile spec/support/ocsp/ecdsa/server.pem --sslCAFile spec/support/ocsp/ecdsa/ca.crt --sslClientCertificate spec/support/ocsp/ecdsa/server.pem

[2022-05-17 18:39:04.963] warning: ignoring unknown argument --sslMode for /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin/mongod
[2022-05-17 18:39:04.963] warning: ignoring unknown argument --sslPEMKeyFile for /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin/mongod
[2022-05-17 18:39:04.963] warning: ignoring unknown argument --sslCAFile for /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin/mongod
[2022-05-17 18:39:04.963] warning: ignoring unknown argument --sslClientCertificate for /data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin/mongod
[2022-05-17 18:39:04.963] launching: "/data/mci/69f54ee9edf83937fb4e49b51dbbac29/src/../drivers-tools/.evergreen/orchestration/mdb/mongodb-linux-x86_64-enterprise-ubuntu1604-4.4.14/bin/mongod" on port 27017

Since mlaunch is aware of both groups of arguments, I think it should accept both forms and translate to the correct one for the server being launched automatically.

I am also curious how mlaunch knows which of these groups of arguments to define, given that path to server is another argument - does the path have to be specified ahead of tls arguments or does tls argument processing gets delayed somehow?

[p-mongo]

Also note that servers through 6.0 recognize ssl arguments, e.g.

serene2% /usr/local/m/versions/6.0/mongod --sslMode x
{"t":{"$date":"2022-05-18T18:17:27.450Z"},"s":"W",  "c":"CONTROL",  "id":23322,   "ctx":"-","msg":"Option: sslMode is deprecated. Please use tlsMode instead."}
{"t":{"$date":"2022-05-18T18:17:27.451Z"},"s":"F",  "c":"CONTROL",  "id":20574,   "ctx":"-","msg":"Error during global initialization","attr":{"error":{"code":2,"codeName":"BadValue","errmsg":"unsupported value for tlsMode x"}}}

mlaunch is therefore rejecting valid server arguments for 4.4-6.0.

[stennie]

mlaunch conditionally defines which options it supports based on server version that it is launching. Specifically it either uses tls names or ssl names.

There are a few aspects to this:

• mlaunch checks the supported parameters reported by mongod --help
• mlaunch assumes TLS options for MongoDB >= 4.2.0 to be consistent with mongod --help
• mlaunch passes through unknown parameters to mongod and mongos unless an exception has been added.

SSL vs TLS options don't fix the expected pattern because:

• SSL aliases continue to be supported but are not listed in the output of mongod --help for 4.2+
• Docs pages for 4.2+ currently mix & match TLS and SSL options

I noticed your test suite is still using the deprecated --ssl options with 4.4. Do you still need to test on EOL versions of MongoDB, or could your incantations be updated to the modern --tls defaults?

[p-mongo]

Drivers support 3.6+ servers presently.

[p-mongo]

Workaround which appears to work through 6.0: https://github.com/p-mongodb/mtools-legacy/commit/886a2e50238a139ac3a206ab5f53779635d9d2a0