Add overriding Mongod settings via the CRD

api/v1/mongodbcommunity_types.go

@@ -323,7 +323,14 @@ type AuthenticationRestriction struct {
 
 // AutomationConfigOverride contains fields which will be overridden in the operator created config.
 type AutomationConfigOverride struct {
-	Processes []OverrideProcess `json:"processes"`
+	Processes  []OverrideProcess  `json:"processes,omitempty"`
+	ReplicaSet OverrideReplicaSet `json:"replicaSet,omitempty"`
+}
+
+type OverrideReplicaSet struct {
+	// +kubebuilder:validation:Type=object
+	// +kubebuilder:pruning:PreserveUnknownFields
+	Settings MapWrapper `json:"settings,omitempty"`
 }
 
 // Note: We do not use the automationconfig.Process type directly here as unmarshalling cannot happen directly

config/crd/bases/mongodbcommunity.mongodb.com_mongodbcommunity.yaml

@@ -180,8 +180,16 @@ spec:
                       - name
                       type: object
                     type: array
-                required:
-                - processes
+                  replicaSet:
+                    properties:
+                      settings:
+                        description: MapWrapper is a wrapper for a map to be used
+                          by other structs. The CRD generator does not support map[string]interface{}
+                          on the top level and hence we need to work around this with
+                          a wrapping struct.
+                        type: object
+                        x-kubernetes-preserve-unknown-fields: true
+                    type: object
                 type: object
               featureCompatibilityVersion:
                 description: FeatureCompatibilityVersion configures the feature compatibility

controllers/replica_set_controller.go

@@ -539,6 +539,11 @@ func buildAutomationConfig(mdb mdbv1.MongoDBCommunity, auth automationconfig.Aut
 		arbitersCount = mdb.Status.CurrentMongoDBArbiters
 	}
 
+	var acOverrideSettings map[string]interface{}
+	if mdb.Spec.AutomationConfigOverride != nil {
+		acOverrideSettings = mdb.Spec.AutomationConfigOverride.ReplicaSet.Settings.Object
+	}
+
 	return automationconfig.NewBuilder().
 		IsEnterprise(guessEnterprise(mdb)).
 		SetTopology(automationconfig.ReplicaSetTopology).
@@ -553,6 +558,7 @@ func buildAutomationConfig(mdb mdbv1.MongoDBCommunity, auth automationconfig.Aut
 		SetFCV(mdb.Spec.FeatureCompatibilityVersion).
 		SetOptions(automationconfig.Options{DownloadBase: "/var/lib/mongodb-mms-automation"}).
 		SetAuth(auth).
+		SetSettings(acOverrideSettings).
 		SetMemberOptions(mdb.Spec.MemberConfig).
 		SetDataDir(mdb.GetMongodConfiguration().GetDBDataDir()).
 		AddModifications(getMongodConfigModification(mdb)).

pkg/automationconfig/automation_config.go

@@ -259,11 +259,12 @@ type ReplSetForceConfig struct {
 }
 
 type ReplicaSet struct {
-	Id              string              `json:"_id"`
-	Members         []ReplicaSetMember  `json:"members"`
-	ProtocolVersion string              `json:"protocolVersion"`
-	NumberArbiters  int                 `json:"numberArbiters"`
-	Force           *ReplSetForceConfig `json:"force,omitempty"`
+	Id              string                 `json:"_id"`
+	Members         []ReplicaSetMember     `json:"members"`
+	ProtocolVersion string                 `json:"protocolVersion"`
+	NumberArbiters  int                    `json:"numberArbiters"`
+	Force           *ReplSetForceConfig    `json:"force,omitempty"`
+	Settings        map[string]interface{} `json:"settings,omitempty"`
 }
 
 type ReplicaSetMember struct {

pkg/automationconfig/automation_config_builder.go

@@ -53,6 +53,7 @@ type Builder struct {
 	port                      int
 	memberOptions             []MemberOptions
 	forceReconfigureToVersion *int64
+	settings                  map[string]interface{}
 }
 
 func NewBuilder() *Builder {
@@ -192,6 +193,11 @@ func (b *Builder) SetAuth(auth Auth) *Builder {
 	return b
 }
 
+func (b *Builder) SetSettings(settings map[string]interface{}) *Builder {
+	b.settings = settings
+	return b
+}
+
 func (b *Builder) SetForceReconfigureToVersion(version int64) *Builder {
 	b.forceReconfigureToVersion = &version
 	return b
@@ -375,6 +381,7 @@ func (b *Builder) Build() (AutomationConfig, error) {
 				ProtocolVersion: "1",
 				NumberArbiters:  b.arbiters,
 				Force:           replSetForceConfig,
+				Settings:        b.settings,
 			},
 		},
 		MonitoringVersions: b.monitoringVersions,

test/e2e/mongodbtests/mongodbtests.go

@@ -398,6 +398,13 @@ func AutomationConfigHasLogRotationConfig(mdb *mdbv1.MongoDBCommunity, lrc *auto
 	}
 }
 
+func AutomationConfigHasSettings(mdb *mdbv1.MongoDBCommunity, settings map[string]interface{}) func(t *testing.T) {
+	return func(t *testing.T) {
+		currentAc := getAutomationConfig(t, mdb)
+		assert.Equal(t, currentAc.ReplicaSets[0].Settings, settings)
+	}
+}
+
 // AutomationConfigReplicaSetsHaveExpectedArbiters verifies that the automation config has the expected version.
 func AutomationConfigReplicaSetsHaveExpectedArbiters(mdb *mdbv1.MongoDBCommunity, expectedArbiters int) func(t *testing.T) {
 	return func(t *testing.T) {

test/e2e/replica_set/replica_set_test.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"testing"
 
+	v1 "github.com/mongodb/mongodb-kubernetes-operator/api/v1"
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/automationconfig"
 	e2eutil "github.com/mongodb/mongodb-kubernetes-operator/test/e2e"
 	"github.com/mongodb/mongodb-kubernetes-operator/test/e2e/mongodbtests"
@@ -77,6 +78,13 @@ func TestReplicaSet(t *testing.T) {
 	}
 	mdb.Spec.MemberConfig = memberOptions
 
+	settings := map[string]interface{}{
+		"electionTimeoutMillis": float64(20),
+	}
+	mdb.Spec.AutomationConfigOverride = &v1.AutomationConfigOverride{
+		ReplicaSet: v1.OverrideReplicaSet{Settings: v1.MapWrapper{Object: settings}},
+	}
+
 	tester, err := FromResource(t, mdb)
 	if err != nil {
 		t.Fatal(err)
@@ -94,5 +102,6 @@ func TestReplicaSet(t *testing.T) {
 		tester.ConnectivitySucceeds(WithURI(mongodbtests.GetSrvConnectionStringForUser(mdb, scramUser))))
 	t.Run("Ensure Authentication", tester.EnsureAuthenticationIsConfigured(3))
 	t.Run("AutomationConfig has the correct version", mongodbtests.AutomationConfigVersionHasTheExpectedVersion(&mdb, 1))
-	t.Run("AutomationCondig has correct member options", mongodbtests.AutomationConfigHasVoteTagPriorityConfigured(&mdb, memberOptions))
+	t.Run("AutomationConfig has correct member options", mongodbtests.AutomationConfigHasVoteTagPriorityConfigured(&mdb, memberOptions))
+	t.Run("AutomationConfig has correct settings", mongodbtests.AutomationConfigHasSettings(&mdb, settings))
 }