Configure TLS Certificates

This section provides guidance on the creation of TLS certificates for each component of MongoDB, and the creation of Kubernetes Secrets in each of your Kubernetes clusters to mount the TLS certificates securely into the appropriate Kubernetes Pods.

The process outlined below utilizes Cert Manager for creating the TLS certificates. However, note that this is an opinionated guide, and CertManager is not supported by MongoDB. Moreover, CertManager is only one of many ways in which you can add TLS certificates to your Kubernetes clusters. Additionally, self-signed certificates may not be suitable for production deployments, depending on the security requirements of your organization. If you require publicly trusted certificates configure your Issuer accordingly or provide the TLS certificate directly. To learn more, see Set Up a cert-manager Integration.

Prerequisites

Before you begin, perform the following tasks:

Install kubectl.
Install Helm.
Set the K8S_CLUSTER_*_CONTEXT_NAME environment variables as explained in the GKE Clusters guide.

Source Code

You can find all included source code in the MongoDB Kubernetes Operator repository.

Procedure

Add the Helm charts repo.

1 helm repo add jetstack https://charts.jetstack.io --force-update

Use Helm to install cert-manager.

1 helm upgrade --install \
2   cert-manager jetstack/cert-manager \
3   --kube-context "${K8S_CLUSTER_0_CONTEXT_NAME}" \
4   --namespace cert-manager \
5   --create-namespace \
6   --set crds.enabled=true

Release "cert-manager" does not exist. Installing it now.
NAME: cert-manager
LAST DEPLOYED: Thu May 22 14:12:18 2025
NAMESPACE: cert-manager
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
cert-manager v1.17.2 has been deployed successfully!
In order to begin issuing certificates, you will need to set up a ClusterIssuer
or Issuer resource (for example, by creating a 'letsencrypt-staging' issuer).
More information on the different types of issuers and how to configure them
can be found in our documentation:
https://cert-manager.io/docs/configuration/
For information on how to configure cert-manager to automatically provision
Certificates for Ingress resources, take a look at the `ingress-shim`
documentation:
https://cert-manager.io/docs/usage/ingress/

Create a certificate issuer.

1 kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
2 apiVersion: cert-manager.io/v1
3 kind: ClusterIssuer
4 metadata:
5   name: selfsigned-cluster-issuer
6 spec:
7   selfSigned: {}
8 EOF
9 
10 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready clusterissuer selfsigned-cluster-issuer
11 
12 kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
13 apiVersion: cert-manager.io/v1
14 kind: Certificate
15 metadata:
16   name: my-selfsigned-ca
17   namespace: cert-manager
18 spec:
19   isCA: true
20   commonName: my-selfsigned-ca
21   secretName: root-secret
22   privateKey:
23     algorithm: ECDSA
24     size: 256
25   issuerRef:
26     name: selfsigned-cluster-issuer
27     kind: ClusterIssuer
28 EOF
29 
30 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready -n cert-manager certificate my-selfsigned-ca
31 
32 kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
33 apiVersion: cert-manager.io/v1
34 kind: ClusterIssuer
35 metadata:
36   name: my-ca-issuer
37 spec:
38   ca:
39     secretName: root-secret
40 EOF
41 
42 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready clusterissuer my-ca-issuer

Verify creation of the issuer.

1 kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
2 apiVersion: cert-manager.io/v1
3 kind: Certificate
4 metadata:
5   name: test-selfsigned-cert
6   namespace: cert-manager
7 spec:
8   dnsNames:
9     - example.com
10   secretName: test-selfsigned-cert-tls
11   issuerRef:
12     name: my-ca-issuer
13     kind: ClusterIssuer
14 EOF
15 
16 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait -n cert-manager --for=condition=Ready certificate test-selfsigned-cert
17 
18 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" delete -n cert-manager certificate test-selfsigned-cert

certificate.cert-manager.io/test-selfsigned-cert created
certificate.cert-manager.io/test-selfsigned-cert condition met
certificate.cert-manager.io "test-selfsigned-cert" deleted

Create CA configMap.

If your Ops Manager TLS certificate is signed by a custom CA, the CA certificate must also contain additional certificates that allows the agents to download MongoDB binaries from the internet. To create the TLS certificate(s), create a ConfigMap to hold the CA certificate:

1 mkdir -p certs
2 
3 openssl s_client -showcerts -verify 2 \
4 -connect downloads.mongodb.com:443 -servername downloads.mongodb.com < /dev/null \
5 | awk '/BEGIN/,/END/{ if(/BEGIN/){a++}; out="certs/cert"a".crt"; print >out}'
6 
7 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" get secret root-secret -n cert-manager -o jsonpath="{.data['ca\.crt']}" | base64 --decode > certs/ca.crt
8 cat certs/ca.crt certs/cert2.crt certs/cert3.crt  >> certs/mms-ca.crt
9 
10 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" create cm ca-issuer -n "${MDB_NAMESPACE}" --from-file=ca-pem=certs/mms-ca.crt --from-file=mms-ca.crt=certs/mms-ca.crt
11 kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" create cm ca-issuer -n "${OM_NAMESPACE}" --from-file=ca-pem=certs/mms-ca.crt --from-file=mms-ca.crt=certs/mms-ca.crt

Back

Deploy the Operator

Multi-Cluster Ops Manager

1	helm upgrade --install \
2	cert-manager jetstack/cert-manager \
3	--kube-context "${K8S_CLUSTER_0_CONTEXT_NAME}" \
4	--namespace cert-manager \
5	--create-namespace \
6	--set crds.enabled=true

1	kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
2	apiVersion: cert-manager.io/v1
3	kind: ClusterIssuer
4	metadata:
5	name: selfsigned-cluster-issuer
6	spec:
7	selfSigned: {}
8	EOF
9
10	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready clusterissuer selfsigned-cluster-issuer
11
12	kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
13	apiVersion: cert-manager.io/v1
14	kind: Certificate
15	metadata:
16	name: my-selfsigned-ca
17	namespace: cert-manager
18	spec:
19	isCA: true
20	commonName: my-selfsigned-ca
21	secretName: root-secret
22	privateKey:
23	algorithm: ECDSA
24	size: 256
25	issuerRef:
26	name: selfsigned-cluster-issuer
27	kind: ClusterIssuer
28	EOF
29
30	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready -n cert-manager certificate my-selfsigned-ca
31
32	kubectl apply --context "${K8S_CLUSTER_0_CONTEXT_NAME}" -f - <<EOF
33	apiVersion: cert-manager.io/v1
34	kind: ClusterIssuer
35	metadata:
36	name: my-ca-issuer
37	spec:
38	ca:
39	secretName: root-secret
40	EOF
41
42	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" wait --for=condition=Ready clusterissuer my-ca-issuer

1	mkdir -p certs
2
3	openssl s_client -showcerts -verify 2 \
4	-connect downloads.mongodb.com:443 -servername downloads.mongodb.com < /dev/null \
5	\| awk '/BEGIN/,/END/{ if(/BEGIN/){a++}; out="certs/cert"a".crt"; print >out}'
6
7	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" get secret root-secret -n cert-manager -o jsonpath="{.data['ca\.crt']}" \| base64 --decode > certs/ca.crt
8	cat certs/ca.crt certs/cert2.crt certs/cert3.crt >> certs/mms-ca.crt
9
10	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" create cm ca-issuer -n "${MDB_NAMESPACE}" --from-file=ca-pem=certs/mms-ca.crt --from-file=mms-ca.crt=certs/mms-ca.crt
11	kubectl --context "${K8S_CLUSTER_0_CONTEXT_NAME}" create cm ca-issuer -n "${OM_NAMESPACE}" --from-file=ca-pem=certs/mms-ca.crt --from-file=mms-ca.crt=certs/mms-ca.crt