Override _id of replicaSet in automation config (complementary to additionalMongodConfig replication.replSetName)

[1st8]

What did you do to encounter the bug?

Steps to reproduce the behavior:

1. Have a legacy (deployed without the operator) MongoDB cluster with--replSet=rs0 in a StatefulSet named mongodb
2. Migrate the cluster nodes to the operator using:

metadata:
  name: mongodb
spec:
  # ...
  additionalMongodConfig:
    replication.replSetName: rs0

What did you expect?

I expected the agent to receive rs0 as _id of the replicaSet when additionalMongodConfig replication.replSetName is used.

Alternatively there could be an override for the replicaSetName under spec directly, so it is used both for the replicaSets._id (agent) and replication.replSetName (mongod).

What happened instead?

It receives mongodb instead.

Screenshots

Additional context

We are looking to migrate 100+ clusters to the operator and this is the last piece in the puzzle.

I confirmed this by stopping the operator and manually changing the _id to rs0 in secret mongodb-config and then seeing the agent become ready.

After starting the operator again, it then undos the changes to the secret, of course.

I had a thorough look through the relevant sources and didn't find a way to fix this with the current implementation.

The automation config builder name is set to the mdb.Name here:

mongodb-kubernetes-operator/controllers/replica_set_controller.go

Line 522 in 85086f7

SetName(mdb.Name).

and then Id is set to b.name here:

mongodb-kubernetes-operator/pkg/automationconfig/automation_config_builder.go

Line 380 in 85086f7

Id: b.name,

b.name is also used to set replication.replSetName here:

mongodb-kubernetes-operator/pkg/automationconfig/automation_config_builder.go

Line 325 in 85086f7

process.SetReplicaSetName(b.name)

so this might suggest that the override solution would be preferable.

Did I miss something?

If I could contribute a fix for this, what should I look out for in my implementation to make it acceptable?

---

• yaml definitions of your MongoDB Deployment(s):

apiVersion: mongodbcommunity.mongodb.com/v1
kind: MongoDBCommunity
metadata:
  name: mongodb
spec:
  members: 3
  type: ReplicaSet
  version: "5.0.28"
  # ...
  additionalMongodConfig:
    replication.replSetName: rs0

• The agent clusterconfig of the faulty members:

{"version":2,"processes":[{"name":"mongodb-0","disabled":false,"hostname":"mongodb-0.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net","args2_6":{"net":{"port":27017},"replication":{"replSetName":"rs0"},"security":{"transitionToAuth":true},"storage":{"dbPath":"/data","wiredTiger":{"engineConfig":{"cacheSizeGB":"0.5","journalCompressor":"zlib"}}}},"featureCompatibilityVersion":"5.0","processType":"mongod","version":"5.0.28","authSchemaVersion":5},{"name":"mongodb-1","disabled":false,"hostname":"mongodb-1.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net","args2_6":{"net":{"port":27017},"replication":{"replSetName":"rs0"},"security":{"transitionToAuth":true},"storage":{"dbPath":"/data","wiredTiger":{"engineConfig":{"cacheSizeGB":"0.5","journalCompressor":"zlib"}}}},"featureCompatibilityVersion":"5.0","processType":"mongod","version":"5.0.28","authSchemaVersion":5},{"name":"mongodb-2","disabled":false,"hostname":"mongodb-2.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net","args2_6":{"net":{"port":27017},"replication":{"replSetName":"rs0"},"security":{"transitionToAuth":true},"storage":{"dbPath":"/data","wiredTiger":{"engineConfig":{"cacheSizeGB":"0.5","journalCompressor":"zlib"}}}},"featureCompatibilityVersion":"5.0","processType":"mongod","version":"5.0.28","authSchemaVersion":5}],"replicaSets":[{"_id":"mongodb","members":[{"_id":0,"host":"mongodb-0","arbiterOnly":false,"votes":1,"priority":1},{"_id":1,"host":"mongodb-1","arbiterOnly":false,"votes":1,"priority":1},{"_id":2,"host":"mongodb-2","arbiterOnly":false,"votes":1,"priority":1}],"protocolVersion":"1","numberArbiters":0}],"auth":{"usersWanted":[{"mechanisms":[],"roles":[{"role":"clusterAdmin","db":"admin"},{"role":"userAdminAnyDatabase","db":"admin"}],"user":"tixxt","db":"admin","authenticationRestrictions":[],"scramSha256Creds":{"iterationCount":15000,"salt":"ntalm9D0Jj4Dt0zYRfBlihEwyc2U/FUfkBsMLQ==","serverKey":"hHycYJGOBRUWuJ/B92ZgY+6zDeyaLA7sVa/ILPADmOw=","storedKey":"pcWfo77fY5yIzGSB1YNsBKvqEHlWaaMCPE1OFc0iZic="},"scramSha1Creds":{"iterationCount":10000,"salt":"a0WKosyWCXTivtM1ywCw+Q==","serverKey":"W04zj/xVioHvjRNjaqH8Di02I8k=","storedKey":"0IjhW1a5s2flWcDoq/TUsWyO6Z4="}}],"disabled":false,"authoritativeSet":false,"autoAuthMechanisms":["SCRAM-SHA-256"],"autoAuthMechanism":"SCRAM-SHA-256","deploymentAuthMechanisms":["SCRAM-SHA-256"],"autoUser":"mms-automation","key":"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","keyfile":"/var/lib/mongodb-mms-automation/authentication/keyfile","keyfileWindows":"%SystemDrive%\\MMSAutomation\\versions\\keyfile","autoPwd":"sG3uBaAQisy09xjuz8dG"},"tls":{"CAFilePath":"","clientCertificateMode":"OPTIONAL"},"mongoDbVersions":[{"name":"5.0.28","builds":[{"platform":"linux","url":"","gitVersion":"","architecture":"amd64","flavor":"rhel","minOsVersion":"","maxOsVersion":"","modules":[]},{"platform":"linux","url":"","gitVersion":"","architecture":"amd64","flavor":"ubuntu","minOsVersion":"","maxOsVersion":"","modules":[]},{"platform":"linux","url":"","gitVersion":"","architecture":"aarch64","flavor":"ubuntu","minOsVersion":"","maxOsVersion":"","modules":[]},{"platform":"linux","url":"","gitVersion":"","architecture":"aarch64","flavor":"rhel","minOsVersion":"","maxOsVersion":"","modules":[]}]}],"backupVersions":[],"monitoringVersions":[],"options":{"downloadBase":"/var/lib/mongodb-mms-automation"}}

• The agent health status of the faulty members:

{"statuses":{"mongodb-0":{"IsInGoalState":false,"LastMongoUpTime":1736175160,"ExpectedToBeUp":true,"ReplicationStatus":1}},"mmsStatus":{"mongodb-0":{"name":"mongodb-0","lastGoalVersionAchieved":1,"plans":[{"automationConfigVersion":1,"started":"2025-01-06T13:24:00.086578872Z","completed":null,"moves":[{"move":"Start","moveDoc":"Start the process","steps":[{"step":"StartFresh","stepDoc":"Start a mongo instance  (start fresh)","isWaitStep":false,"started":"2025-01-06T13:24:00.08660494Z","completed":"2025-01-06T13:24:09.865099778Z","result":"success"}]},{"move":"WaitAllRsMembersUp","moveDoc":"Wait until all members of this process' repl set are up","steps":[{"step":"WaitAllRsMembersUp","stepDoc":"Wait until all members of this process' repl set are up","isWaitStep":true,"started":"2025-01-06T13:24:09.865192101Z","completed":null,"result":"wait"}]},{"move":"RsInit","moveDoc":"Initialize a replica set including the current MongoDB process","steps":[{"step":"RsInit","stepDoc":"Initialize a replica set","isWaitStep":false,"started":null,"completed":null,"result":""}]},{"move":"WaitFeatureCompatibilityVersionCorrect","moveDoc":"Wait for featureCompatibilityVersion to be right","steps":[{"step":"WaitFeatureCompatibilityVersionCorrect","stepDoc":"Wait for featureCompatibilityVersion to be right","isWaitStep":true,"started":null,"completed":null,"result":""}]}]},{"automationConfigVersion":1,"started":"2025-01-06T13:35:35.257483563Z","completed":"2025-01-06T13:35:39.182499358Z","moves":[{"move":"EnsureAutomationCredentials","moveDoc":"Ensure the automation user exists","steps":[{"step":"EnsureAutomationCredentials","stepDoc":"Ensure the automation user exists","isWaitStep":false,"started":"2025-01-06T13:35:35.257505082Z","completed":"2025-01-06T13:35:39.022009499Z","result":"success"}]},{"move":"AdjustUsers","moveDoc":"Adjust Users","steps":[{"step":"AdjustUsers","stepDoc":"Adjust Users","isWaitStep":false,"started":"2025-01-06T13:35:39.022147572Z","completed":"2025-01-06T13:35:39.182354797Z","result":"success"}]}]}],"errorCode":104,"errorString":"\u003cmongodb-0\u003e [14:51:42.024] Failed to find a plan!","waitDetails":{"WaitAllRsMembersUp":"[]","WaitAuthSchemaCorrect":"auth schema will be updated by the primary","WaitCanStartFresh":"process not up","WaitCannotBecomePrimary":"Wait until the process is reconfigured with priority=0 by a different process","WaitDefaultRWConcernCorrect":"waiting for the primary to update defaultRWConcern","WaitForResyncPrimaryManualInterventionStep":"A resync was requested on a primary. This requires manual intervention","WaitHealthyMajority":"[]","WaitMultipleHealthyNonArbiters":"[]","WaitNecessaryRsMembersUpForReconfig":"[]","WaitPrimary":"This process is expected to be the primary member. Check that the replica set state allows a primary to be elected","WaitProcessUp":"The process is running, but not yet responding to agent calls","WaitResetPlacementHistory":"config servers  haven't seen the marker"}}}

• The verbose agent logs of the faulty members:

[2025-01-06T14:53:42.436+0000] [.warn] [src/director/director.go:computePlan:297] <mongodb-0> [14:53:42.436] ... No plan could be found - not in goal state because of:
[All the following are false:
    ['desiredState.ReplSetConf' != <nil> ('desiredState.ReplSetConf' = ReplSetConfig{id=mongodb,version=0,commitmentStatus=false,configsvr=false,protocolVersion=1,forceProtocolVersion=false,writeConcernMajorityJournalDefault=,members={id:0,HostPort:mongodb-0.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net:27017,ArbiterOnly:falsePriority:1,Hidden:false,SecondaryDelaySecs:0,Votes:1,Tags:map[]},{id:1,HostPort:mongodb-1.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net:27017,ArbiterOnly:falsePriority:1,Hidden:false,SecondaryDelaySecs:0,Votes:1,Tags:map[]},{id:2,HostPort:mongodb-2.service-mongodb.mongodb.svc.test.kubernetes.local.mixxt.net:27017,ArbiterOnly:falsePriority:1,Hidden:false,SecondaryDelaySecs:0,Votes:1,Tags:map[]},settings=map[]})]
    ['currentState.ReplSetConf.Id' != 'desiredState.ReplSetConf.Id' : (rs0) vs. (mongodb)]

Also seen previously:

(InvalidReplicaSetConfig) Rejecting initiate with a set name that differs from command line set name, initiate set name: mongodb, command line set name: rs0

[1st8]

What do you think about adding a new Id string in OverrideReplicaSet?

mongodb-kubernetes-operator/api/v1/mongodbcommunity_types.go

Lines 330 to 334 in 85086f7

	type OverrideReplicaSet struct {
	// +kubebuilder:validation:Type=object
	// +kubebuilder:pruning:PreserveUnknownFields
	Settings MapWrapper `json:"settings,omitempty"`
	}

So that this would work:

spec:
  automationConfig:
    replicaSet:
      id: rs0