• Deploy and Configure MongoDB Database Resources >
• Secure a Database Resource >
• Secure Client Authentication with X.509

Secure Client Authentication with X.509

The MongoDB Enterprise Kubernetes Operator can use X.509 certificates to authenticate your client applications to your MongoDB deployments.

This guide instructs you on how to configure:

• X.509 authentication from clients to your MongoDB instances.
• TLS to encrypt connections between MongoDB hosts in a replica set or sharded cluster.
• TLS to encrypt connections between client applications and MongoDB deployments.

Note

You can’t secure a Standalone Instance of MongoDB in a Kubernetes cluster.

General Prerequisites

Before you secure your MongoDB deployment using TLS encryption, complete the following:

• Install the Kubernetes Operator
• Create Credentials for the Kubernetes Operator

Enabling X.509 authentication at the project level configures all agents to use X.509 client authentication when communicating with MongoDB deployments.

X.509 client authentication requires one of the following:

• Cloud Manager
• Ops Manager 4.1.7 or later
• Ops Manager 4.0.11 or later

Configure X.509 Client Authentication for a Replica Set

Prerequisites

Before you secure your replica set using TLS encryption, complete the following:

• Deploy the Replica Set that you want to secure

• Generate one TLS certificate for each of the following components:

  • Your replica set. Ensure that you add SANs for each Kubernetes pod that hosts a member of your replica set to the certificate.

    In your TLS certificate, the SAN for each pod must use the following format:

    copy

    <pod-name>.<metadata.name>-svc.<namespace>.svc.cluster.local
    

  • Your project’s MongoDB Agent. For the MongoDB Agent certificate, ensure that you meet the following requirements:
    • The Common Name in the TLS certificate is not empty.
    • The combined Organization and Organizational Unit in each TLS certificate differs from the Organization and Organizational Unit in the TLS certificate for your replica set members.

• You must possess the CA certificate and the key that you used to sign your TLS certificates.

Important

For fresh Kubernetes Operator installations starting with version 1.13, the Kubernetes Operator uses kubernetes.io/tls secrets to store TLS certificates and private keys for Ops Manager and MongoDB resources.

Previous Kubernetes Operator versions required you to concatenate your TLS certificates and private keys into a PEM file and store this file in an Opaque secret.

To maintain backwards compatibility, the Kubernetes Operator continues to support storing PEM files in Opaque secrets. Support of this feature might be removed in a future release.

We recommend that you upgrade to Kubernetes Operator version 1.15.1 or later.

If you have a broken Application Database after upgrading to Kubernetes Operator version 1.14.0 or 1.15.0, see Ops Manager in Failed State.

Create X.509 Certificates for a Replica Set

1

Configure kubectl to default to your namespace.

If you have not already, run the following command to execute all kubectl commands in the namespace you created:

copy

kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>

2

Create the secret for your replica set’s TLS certificate.

Run this kubectl command to create a new secret that stores the replica set’s certificate:

copy

kubectl create secret tls <prefix>-<metadata.name>-cert \
  --cert=<replica-set-tls-cert> \
  --key=<replica-set-tls-key>

Note

You must prefix your secrets with <prefix>-<metadata.name>.

Example

If you call your deployment my-replica-set and you set the prefix to mdb, you must name the TLS secret for the client TLS communications mdb-my-replica-set-cert. Also, you must name the TLS secret for internal cluster authentication (if enabled) mdb-my-replica-set-clusterfile.

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

To learn about your options for secret storage, see Configure Secret Storage.

3

Create the secret for your agent’s X.509 certificate.

Run this kubectl command to create a new secret that stores the agent’s X.509 certificate:

copy

kubectl create secret tls <prefix>-<metadata.name>-agent-certs \
  --cert=<agent-tls-cert> \
  --key=<agent-tls-key>

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

4

Create the ConfigMap to link your CA with your deployment.

Run this kubectl command to link your CA to your replica set:

copy

kubectl create configmap custom-ca --from-file=ca-pem

5

Copy the sample replica set resource.

Change the settings of this YAML file to match your desired replica set configuration.

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-replica-set>
spec:
  members: 3
  version: "4.2.2-ent"
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
            # Must match metadata.name in ConfigMap file
  credentials: <mycredentials>
  type: ReplicaSet
  persistent: true

copy

  security:
    tls:
      ca: <custom-ca>
    certsSecretPrefix: <prefix>
    authentication:
      enabled: true
      modes: ["X509"]
...

6

Paste the copied example section into your existing replica set resource.

Open your preferred text editor and paste the object specification at the end of your resource file in the spec section.

7

Configure the TLS settings for your replica set resource using a Custom Certificate Authority.

To enable TLS in your deployment, configure the following settings in your Kubernetes object:

Key	Type	Necessity	Description	Example
spec.security .tls.ca	string	Required	Add the ConfigMap’s name that stores the custom CA that you used to sign your deployment’s TLS certificates.	<custom-ca>
spec.security .certsSecretPrefix	string	Required	Add the <prefix> of the secret name that contains your MongoDB deployment’s TLS certificates. Example If you call your deployment my-replica-set and you set the prefix to mdb, you must name the TLS secret for the client TLS communications mdb-my-replica-set-cert. Also, you must name the TLS secret for internal cluster authentication (if enabled) mdb-my-replica-set-clusterfile.	devDb

8

Configure the general X.509 settings for your replica set resource.

To enable TLS and X.509 in your deployment, configure the following settings in your Kubernetes object:

Key	Type	Necessity	Description	Example
spec.security .authentication .enabled	boolean	Required	Set this value to true to enable authentication on the MongoDB deployment.	true
spec.security .authentication .modes	array	Conditional	Set this value to ["X509"].	["X509"]

9

Save your replica set config file.

10

Apply your changes to your replica set deployment.

Invoke the following Kubernetes command to update your replica set:

copy

kubectl apply -f <replica-set-conf>.yaml

11

Track the status of your deployment.

To check the status of your MongoDB Kubernetes resource, invoke the following command:

copy

kubectl get mdb <resource-name> -o yaml -w

The -w flag means “watch”. With the “watch” flag set, the output refreshes immediately when the configuration changes until the status phase achieves the Running state.

See Troubleshoot the Kubernetes Operator for information about the resource deployment statuses.

Renew X.509 Certificates for a Replica Set

If you have already created certificates, we recommend that you renew them periodically using the following procedure.

1

Configure kubectl to default to your namespace.

If you have not already, run the following command to execute all kubectl commands in the namespace you created:

copy

kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>

2

Renew the secret for your TLS certificates.

Run this kubectl command to renew an existing secret that stores the replica set’s certificates:

copy

kubectl create secret tls <prefix>-<metadata.name>-cert \
  --cert=<replica-set-tls-cert> \
  --key=<replica-set-tls-key> \
  --dry-run=client \
   -o yaml |
kubectl apply -f -

This example covers a three-member replica set. If you have more than three members, you can add them to the certificate using the --from-file option.

3

Renew the secret for your agents’ X.509 certificates.

Run this kubectl command to renew an existing secret that stores the agents’ X.509 certificates:

copy

kubectl create secret tls <prefix>-<metadata.name>-agent-certs \
  --cert=<agent-tls-cert> \
  --key=<agent-tls-key> \
  --dry-run=client \
   -o yaml |
kubectl apply -f -

Configure X.509 Client Authentication for a Sharded Cluster

Prerequisites

Before you secure your replica set using TLS encryption, complete the following:

• Deploy the Sharded Cluster that you want to secure

• Generate one TLS certificate for each of the following components:

  • Each shard in your sharded cluster. Ensure that you add SANs for each Kubernetes pod that hosts a shard member to the certificate.

    In your TLS certificates, the SAN for each shard pod must use the following format:

    copy

    <pod-name>.<metadata.name>-sh.<namespace>.svc.cluster.local
    

  • Your config servers. Ensure that you add SANs for each Kubernetes pod that hosts your config servers to the certificate.

    In your TLS certificates, the SAN for each config server pod must use the following format:

    copy

    <pod-name>.<metadata.name>-cs.<namespace>.svc.cluster.local
    

  • Your mongos instances. Ensure that you add SANs for each Kubernetes pod that hosts a mongos to the certificate.

    In your TLS certificates, the SAN for each mongos pod must use this format:

    copy

    <pod-name>.<metadata.name>-svc.<namespace>.svc.cluster.local
    

  • Your project’s MongoDB Agent. For the MongoDB Agent certificate, ensure that you meet the following requirements:
    • The Common Name in the TLS certificate is not empty.
    • The combined Organization and Organizational Unit in each TLS certificate differs from the Organization and Organizational Unit in the TLS certificate for your replica set members.

• You must possess the CA certificate and the key that you used to sign your TLS certificates.

Important

For fresh Kubernetes Operator installations starting with version 1.13, the Kubernetes Operator uses kubernetes.io/tls secrets to store TLS certificates and private keys for Ops Manager and MongoDB resources.

Previous Kubernetes Operator versions required you to concatenate your TLS certificates and private keys into a PEM file and store this file in an Opaque secret.

To maintain backwards compatibility, the Kubernetes Operator continues to support storing PEM files in Opaque secrets. Support of this feature might be removed in a future release.

We recommend that you upgrade to Kubernetes Operator version 1.15.1 or later.

If you have a broken Application Database after upgrading to Kubernetes Operator version 1.14.0 or 1.15.0, see Ops Manager in Failed State.

Create X.509 Certificates for a Sharded Cluster

1

Configure kubectl to default to your namespace.

If you have not already, run the following command to execute all kubectl commands in the namespace you created:

copy

kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>

2

Create the secret for your Shards’ TLS certificates.

Run this kubectl command to create a new secret that stores the sharded cluster shards’ certificates:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-0-cert \
  --cert=<shard-0-tls-cert> \
  --key=<shard-0-tls-key>

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-1-cert \
  --cert=<shard-1-tls-cert> \
  --key=<shard-1-tls-key>

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

3

Create the secret for your config servers’ TLS certificate.

Run this kubectl command to create a new secret that stores the sharded cluster config servers’ certificate:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-config-cert \
  --cert=<config-tls-cert> \
  --key=<config-tls-key>

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

4

Create the secret for your mongos servers’ TLS certificate.

Run this kubectl command to create a new secret that stores the sharded cluster mongos certificate:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-mongos-cert \
  --cert=<mongos-tls-cert> \
  --key=<mongos-tls-key>

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

5

Create the secret for your agent’s X.509 certificate.

Run this kubectl command to create a new secret that stores the agent’s X.509 certificate:

copy

kubectl create secret tls <prefix>-<metadata.name>-agent-certs \
  --cert=<agent-tls-cert> \
  --key=<agent-tls-key>

If you’re using HashiCorp Vault as your secret storage tool, you can Create a Vault Secret instead.

6

Copy the sample sharded cluster resource.

Change the settings of this YAML file to match your desired sharded cluster configuration.

---
apiVersion: mongodb.com/v1
kind: MongoDB
metadata:
  name: <my-sharded-cluster>
spec:
  shardCount: 2
  mongodsPerShardCount: 3
  mongosCount: 2
  configServerCount: 3
  version: "4.2.2-ent"
  opsManager:
    configMapRef:
      name: <configMap.metadata.name>
            # Must match metadata.name in ConfigMap file
  credentials: <mycredentials>
  type: ShardedCluster
  persistent: true

copy

  security:
    tls:
      ca: <custom-ca>
    certsSecretPrefix: <prefix>
    authentication:
      enabled: true
      modes: ["X509"]
...

7

Paste the copied example section into your existing sharded cluster resource.

Open your preferred text editor and paste the object specification at the end of your resource file in the spec section.

8

Configure the TLS settings for your sharded cluster resource using a Custom Certificate Authority.

To enable TLS in your deployment, configure the following settings in your Kubernetes object:

Key	Type	Necessity	Description	Example
spec.security .tls.ca	string	Required	Add the ConfigMap’s name that stores the custom CA that you used to sign your deployment’s TLS certificates.	<custom-ca>
spec.security .certsSecretPrefix	string	Required	Add the <prefix> of the secret name that contains your MongoDB deployment’s TLS certificates. Example If you call your deployment my-replica-set and you set the prefix to mdb, you must name the TLS secret for the client TLS communications mdb-my-replica-set-cert. Also, you must name the TLS secret for internal cluster authentication (if enabled) mdb-my-replica-set-clusterfile.	devDb

9

Configure the general X.509 settings for your sharded cluster resource.

To enable TLS and X.509 in your deployment, configure the following settings in your Kubernetes object:

Key	Type	Necessity	Description	Example
spec.security .authentication .enabled	boolean	Required	Set this value to true to enable authentication on the MongoDB deployment.	true
spec.security .authentication .modes	array	Conditional	Set this value to ["X509"].	["X509"]

10

Save your sharded cluster config file.

11

Update and restart your sharded cluster deployment.

In any directory, invoke the following Kubernetes command to update and restart your {k8sResource}}:

copy

kubectl apply -f <sharded-cluster-conf>.yaml

12

Track the status of your deployment.

To check the status of your MongoDB Kubernetes resource, invoke the following command:

copy

kubectl get mdb <resource-name> -o yaml -w

The -w flag means “watch”. With the “watch” flag set, the output refreshes immediately when the configuration changes until the status phase achieves the Running state.

See Troubleshoot the Kubernetes Operator for information about the resource deployment statuses.

Renew X.509 Certificates for a Sharded Cluster

If you have already created certificates, we recommend that you renew them periodically using the following procedure.

1

Configure kubectl to default to your namespace.

If you have not already, run the following command to execute all kubectl commands in the namespace you created:

copy

kubectl config set-context $(kubectl config current-context) --namespace=<metadata.namespace>

2

Renew the secret for your Shards’ TLS certificates.

Run this kubectl command to renew an existing secret that stores the sharded cluster shards’ certificates:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-0-cert \
  --cert=<shard-0-tls-cert> \
  --key=<shard-0-tls-key> \
  --dry-run=client \
  -o yaml |
kubectl apply -f -

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-1-cert \
  --cert=<shard-1-tls-cert> \
  --key=<shard-1-tls-key> \
  --dry-run=client \
  -o yaml |
kubectl apply -f -

3

Renew the secret for your config server’s TLS certificates.

Run this kubectl command to renew an existing secret that stores the sharded cluster config server’s certificates:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-config-cert \
  --cert=<config-tls-cert> \
  --key=<config-tls-key> \
  --dry-run=client \
  -o yaml |
kubectl apply -f -

4

Renew the secret for your mongos server’s TLS certificates.

Run this kubectl command to renew an existing secret that stores the sharded cluster mongos certificates:

copy

kubectl -n mongodb create secret tls <prefix>-<metadata.name>-mongos-cert \
  --cert=<mongos-tls-cert> \
  --key=<mongos-tls-key> \
  --dry-run=client \
  -o yaml |
kubectl apply -f -

5

Renew the secret for your agents’ X.509 certificates.

Run this kubectl command to renew an existing secret that stores the agents’ X.509 certificates:

copy

kubectl create secret tls <prefix>-<metadata.name>-agent-certs \
  --cert=<agent-tls-cert> \
  --key=<agent-tls-key> \
  --dry-run=client \
   -o yaml |
kubectl apply -f -

© MongoDB, Inc 2008-present. MongoDB, Mongo, and the leaf logo are registered trademarks of MongoDB, Inc.