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Reconfigure Postgres TLS/SSL (Transport Encryption)
KubeDB supports reconfigure i.e. add, remove, update and rotation of TLS/SSL certificates, changing issuer for existing Postgres database via a PostgresOpsRequest. This tutorial will show you how to use KubeDB to reconfigure TLS/SSL encryption.
Before You Begin
At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
Install
cert-manger
v1.0.0 or later to your cluster to manage your SSL/TLS certificates from here.Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.
To keep things isolated, this tutorial uses a separate namespace called
demo
throughout this tutorial.$ kubectl create ns demo namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/postgres folder in GitHub repository kubedb/docs.
Add TLS to a Postgres database
Here, We are going to create a Postgres database without TLS and then reconfigure the database to use TLS.
Deploy Postgres without TLS
In this section, we are going to deploy a Postgres Replicaset database without TLS. In the next few sections we will reconfigure TLS using PostgresOpsRequest
CRD. Below is the YAML of the Postgres
CR that we are going to create,
apiVersion: kubedb.com/v1
kind: Postgres
metadata:
name: ha-postgres
namespace: demo
spec:
replicas: 3
storageType: Durable
deletionPolicy: WipeOut
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
version: "13.13"
Let’s create the Postgres
CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/ha-postgres.yaml
postgres.kubedb.com/ha-postgres created
Now, wait until ha-postgres
has status Ready
. i.e,
$ kubectl get pg -n demo
NAME VERSION STATUS AGE
ha-postgres 13.13 Ready 87s
$ kubectl dba describe postgres ha-postgres -n demo
Name: ha-postgres
Namespace: demo
CreationTimestamp: Mon, 19 Aug 2024 13:38:28 +0600
Labels: <none>
Replicas: 3 total
Status: Ready
StorageType: Durable
Volume:
StorageClass: standard
Capacity: 1Gi
Access Modes: RWO
Paused: false
Halted: false
Termination Policy: WipeOut
Service:
Name: ha-postgres
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=ha-postgres
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=postgreses.kubedb.com
Annotations: <none>
Type: ClusterIP
IP: 10.96.193.243
Port: primary 5432/TCP
TargetPort: db/TCP
Endpoints: 10.244.0.76:5432
Port: coordinatclient 2379/TCP
TargetPort: coordinatclient/TCP
Endpoints: 10.244.0.76:2379
Service:
Name: ha-postgres-pods
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=ha-postgres
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=postgreses.kubedb.com
Annotations: <none>
Type: ClusterIP
IP: None
Port: db 5432/TCP
TargetPort: db/TCP
Endpoints: 10.244.0.76:5432,10.244.0.78:5432,10.244.0.80:5432
Port: coordinator 2380/TCP
TargetPort: coordinator/TCP
Endpoints: 10.244.0.76:2380,10.244.0.78:2380,10.244.0.80:2380
Port: coordinatclient 2379/TCP
TargetPort: coordinatclient/TCP
Endpoints: 10.244.0.76:2379,10.244.0.78:2379,10.244.0.80:2379
Service:
Name: ha-postgres-standby
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=ha-postgres
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=postgreses.kubedb.com
Annotations: <none>
Type: ClusterIP
IP: 10.96.65.45
Port: standby 5432/TCP
TargetPort: db/TCP
Endpoints: 10.244.0.78:5432,10.244.0.80:5432
Auth Secret:
Name: ha-postgres-auth
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=ha-postgres
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=postgreses.kubedb.com
Annotations: <none>
Type: kubernetes.io/basic-auth
Data:
password: 16 bytes
username: 8 bytes
Topology:
Type Pod StartTime Phase
---- --- --------- -----
primary ha-postgres-0 2024-08-19 13:38:34 +0600 +06 Running
ha-postgres-1 2024-08-19 13:38:41 +0600 +06 Running
ha-postgres-2 2024-08-19 13:38:48 +0600 +06 Running
AppBinding:
Metadata:
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"kubedb.com/v1","kind":"Postgres","metadata":{"annotations":{},"name":"ha-postgres","namespace":"demo"},"spec":{"deletionPolicy":"WipeOut","replicas":3,"storage":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"},"storageType":"Durable","version":"13.13"}}
Creation Timestamp: 2024-08-19T07:38:31Z
Labels:
app.kubernetes.io/component: database
app.kubernetes.io/instance: ha-postgres
app.kubernetes.io/managed-by: kubedb.com
app.kubernetes.io/name: postgreses.kubedb.com
Name: ha-postgres
Namespace: demo
Spec:
App Ref:
API Group: kubedb.com
Kind: Postgres
Name: ha-postgres
Namespace: demo
Client Config:
Service:
Name: ha-postgres
Path: /
Port: 5432
Query: sslmode=disable
Scheme: postgresql
Parameters:
API Version: appcatalog.appscode.com/v1alpha1
Kind: StashAddon
Stash:
Addon:
Backup Task:
Name: postgres-backup-13.1
Restore Task:
Name: postgres-restore-13.1
Secret:
Name: ha-postgres-auth
Type: kubedb.com/postgres
Version: 13.13
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Successful 2m KubeDB Operator Successfully created governing service
Normal Successful 2m KubeDB Operator Successfully created Service
Normal Successful 2m KubeDB Operator Successfully created Service
Normal Successful 2m KubeDB Operator Successfully created Postgres
Normal Successful 49s KubeDB Operator Successfully patched Postgres
Now, we can connect to this database through psql
and verify that the TLS is disabled.
$ kubectl get secrets -n demo ha-postgres-auth -o jsonpath='{.data.\username}' | base64 -d
postgres
$ kubectl get secrets -n demo ha-postgres-auth -o jsonpath='{.data.\password}' | base64 -d
U6(h_pYrekLZ2OOd
$ kubectl exec -it -n demo ha-postgres-0 -- bash
Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init)
ha-postgres-0:/$ psql -h ha-postgres.demo.svc -U postgres
Password for user postgres:
psql (13.13)
Type "help" for help.
postgres=#
postgres=# SELECT name, setting FROM pg_settings WHERE name IN ('ssl');
name | setting
------+---------
ssl | off
(1 row)
We can verify from the above output that TLS is disabled for this database.
Create Issuer/ ClusterIssuer
Now, We are going to create an example Issuer
that will be used to enable SSL/TLS in Postgres. Alternatively, you can follow this cert-manager tutorial to create your own Issuer
.
- Start off by generating a ca certificates using openssl.
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=ca/O=kubedb"
Generating a RSA private key
................+++++
........................+++++
writing new private key to './ca.key'
-----
- Now we are going to create a ca-secret using the certificate files that we have just generated.
$ kubectl create secret tls postgres-ca \
--cert=ca.crt \
--key=ca.key \
--namespace=demo
secret/postgres-ca created
Now, Let’s create an Issuer
using the postgres-ca
secret that we have just created. The YAML
file looks like this:
apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
name: pg-issuer
namespace: demo
spec:
ca:
secretName: postgres-ca
Let’s apply the YAML
file:
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/issuer.yaml
issuer.cert-manager.io/pg-issuer created
$ kubectl get issuer -n demo
NAME READY AGE
pg-issuer True 11s
Issuer is ready(true).
Create PostgresOpsRequest
In order to add TLS to the database, we have to create a PostgresOpsRequest
CRO with our created issuer. Below is the YAML of the PostgresOpsRequest
CRO that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: add-tls
namespace: demo
spec:
type: ReconfigureTLS
databaseRef:
name: ha-postgres
tls:
sslMode: verify-full
clientAuthMode: cert
issuerRef:
name: pg-issuer
kind: Issuer
apiGroup: "cert-manager.io"
certificates:
- alias: client
subject:
organizations:
- postgres
organizationalUnits:
- client
apply: Always
Here,
spec.databaseRef.name
specifies that we are performing reconfigure TLS operation onha-postgres
database.spec.type
specifies that we are performingReconfigureTLS
on our database.spec.tls.issuerRef
specifies the issuer name, kind and api group.spec.tls.certificates
specifies the certificates.
Let’s create the PostgresOpsRequest
CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/add-tls.yaml
postgresopsrequest.ops.kubedb.com/add-tls created
Verify TLS Enabled Successfully
Let’s wait for PostgresOpsRequest
to be Successful
. Run the following command to watch PostgresOpsRequest
CRO,
$ kubectl get pgops -n demo add-tls
NAME TYPE STATUS AGE
add-tls ReconfigureTLS Successful 5m23s
We can see from the above output that the PostgresOpsRequest
has succeeded.
Now, Let’s exec into a database primary pods to see if certificates are added there.
$ kubectl exec -it -n demo ha-postgres-0 -- bash
Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init)
ha-postgres-0:/$ ls -R /tls
tls:
certs
tls/certs:
client exporter server
tls/certs/client:
ca.crt client.crt client.key
tls/certs/exporter:
ca.crt tls.crt tls.key
tls/certs/server:
ca.crt server.crt server.key
All the certs are added. Now lets connect with the postgres using client certs
$ kubectl exec -it -n demo ha-postgres-0 -- bash
Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init)
ha-postgres-0:/$ psql -h ha-postgres.demo.svc -U postgres -d "sslmode=verify-full sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key"
psql (13.13)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Type "help" for help.
postgres=#
We can see our connection is now SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Lets check whether ssl is on.
postgres=# SELECT name, setting
postgres-# FROM pg_settings
postgres-# WHERE name IN ('ssl', 'ssl_cert_file', 'ssl_key_file');
name | setting
---------------+------------------------------
ssl | on
ssl_cert_file | /tls/certs/server/server.crt
ssl_key_file | /tls/certs/server/server.key
(3 rows)
Note: We by default set local connection to trust. So you can connect to postgres without password or certificate from inside of the pods.
$ kubectl exec -it -n demo ha-postgres-0 -- bash Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init) ha-postgres-0:/$ psql psql (13.13) Type "help" for help. postgres=#
Rotate Certificate
Now we are going to rotate the certificate of this database. First let’s check the current expiration date of the certificate.
kubectl get secrets -n demo ha-postgres-client-cert -o jsonpath='{.data.ca\.crt}' | base64 -d | openssl x509 -noout -dates
notBefore=Aug 21 05:25:05 2024 GMT
notAfter=Nov 19 05:25:05 2024 GMT
So, the certificate will expire on this time Nov 19 05:25:05 2024 GMT
.
Create PostgresOpsRequest
Now we are going to increase it using a PostgresOpsRequest. Below is the yaml of the ops request that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: rotate-tls
namespace: demo
spec:
type: ReconfigureTLS
databaseRef:
name: ha-postgres
tls:
rotateCertificates: true
Here,
spec.databaseRef.name
specifies that we are performing reconfigure TLS operation onha-postgres
database.spec.type
specifies that we are performingReconfigureTLS
on our database.spec.tls.rotateCertificates
specifies that we want to rotate the certificate of this database.
Let’s create the PostgresOpsRequest
CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/rotate-tls.yaml
postgresopsrequest.ops.kubedb.com/rotate-tls created
Verify Certificate Rotated Successfully
Let’s wait for PostgresOpsRequest
to be Successful
. Run the following command to watch PostgresOpsRequest
CRO,
$ kubectl get pgops -n demo
NAME TYPE STATUS AGE
rotate-tls ReconfigureTLS Successful 3m10s
We can see from the above output that the PostgresOpsRequest
has succeeded. And we can check that the tls.crt has been updated.
$ kubectl get secrets -n demo ha-postgres-client-cert -o jsonpath='{.data.tls\.crt}' | base64 -d | openssl x509 -noout -dates
notBefore=Aug 21 05:40:49 2024 GMT
notAfter=Nov 19 05:40:49 2024 GMT
$ kubectl get secrets -n demo ha-postgres-server-cert -o jsonpath='{.data.tls\.crt}' | base64 -d | openssl x509 -noout -dates
notBefore=Aug 21 05:40:49 2024 GMT
notAfter=Nov 19 05:40:49 2024 GMT
As we can see from the above output, the certificate has been rotated successfully.
Change Issuer/ClusterIssuer
Now, we are going to change the issuer of this database.
- Let’s create a new ca certificate and key using a different subject
CN=ca-update,O=kubedb-updated
.
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=ca-updated/O=kubedb-updated"
Generating a RSA private key
..............................................................+++++
......................................................................................+++++
writing new private key to './ca.key'
-----
- Now we are going to create a new ca-secret using the certificate files that we have just generated.
$ kubectl create secret tls postgres-new-ca \
--cert=ca.crt \
--key=ca.key \
--namespace=demo
secret/postgres-new-ca created
Now, Let’s create a new Issuer
using the postgres-new-ca
secret that we have just created. The YAML
file looks like this:
apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
name: pg-new-issuer
namespace: demo
spec:
ca:
secretName: postgres-new-ca
Let’s apply the YAML
file:
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/new-issuer.yaml
issuer.cert-manager.io/pg-new-issuer created
Create PostgresOpsRequest
In order to use the new issuer to issue new certificates, we have to create a PostgresOpsRequest
CRO with the newly created issuer. Below is the YAML of the PostgresOpsRequest
CRO that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: change-issuer
namespace: demo
spec:
type: ReconfigureTLS
databaseRef:
name: ha-postgres
tls:
issuerRef:
name: pg-new-issuer
kind: Issuer
apiGroup: "cert-manager.io"
Here,
spec.databaseRef.name
specifies that we are performing reconfigure TLS operation onha-postgres
database.spec.type
specifies that we are performingReconfigureTLS
on our database.spec.tls.issuerRef
specifies the issuer name, kind and api group.
Let’s create the PostgresOpsRequest
CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/change-issuer.yaml
postgresopsrequest.ops.kubedb.com/change-issuer created
Verify Issuer is changed successfully
Let’s wait for PostgresOpsRequest
to be Successful
. Run the following command to watch PostgresOpsRequest
CRO,
$ kubectl get pgops -n demo change-issuer
NAME TYPE STATUS AGE
change-issuer ReconfigureTLS Successful 3m54s
We can see from the above output that the PostgresOpsRequest
has succeeded.
Now, Let’s exec into a database node and find out the ca subject to see if it matches the one we have provided.
$ kubectl get secrets -n demo ha-postgres-client-cert -o jsonpath='{.data.ca\.crt}' | base64 -d | openssl x509 -noout -subject
subject=CN = ca-updated, O = kubedb-updated
$ kubectl get secrets -n demo ha-postgres-server-cert -o jsonpath='{.data.ca\.crt}' | base64 -d | openssl x509 -noout -subject
subject=CN = ca-updated, O = kubedb-updated
# other way to check this is
$ kubectl exec -it -n demo ha-postgres-0 -- bash
Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init)
ha-postgres-0:/$ cat /tls/certs/server/ca.crt
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
Now you can check here.
We can see from the above output that, the subject name matches the subject name of the new ca certificate that we have created. So, the issuer is changed successfully.
Remove TLS from the Database
Now, we are going to remove TLS from this database using a PostgresOpsRequest.
Create PostgresOpsRequest
Below is the YAML of the PostgresOpsRequest
CRO that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: remove-tls
namespace: demo
spec:
type: ReconfigureTLS
databaseRef:
name: ha-postgres
tls:
clientAuthMode: md5
remove: true
timeout: 5m
apply: IfReady
Here,
spec.databaseRef.name
specifies that we are performing reconfigure TLS operation onha-postgres
database.spec.type
specifies that we are performingReconfigureTLS
on our database.spec.tls.remove
specifies that we want to remove tls from this database.spec.tls.clientAuthMode
defines clientAuthentication mode after removing tls. It can’t becert
. Possible values aremd5
scram
.
Let’s create the PostgresOpsRequest
CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/postgres/reconfigure-tls/remove-tls.yaml
postgresopsrequest.ops.kubedb.com/remove-tls created
Verify TLS Removed Successfully
Let’s wait for PostgresOpsRequest
to be Successful
. Run the following command to watch PostgresOpsRequest
CRO,
$ kubectl get pgops -n demo remove-tls
NAME TYPE STATUS AGE
remove-tls ReconfigureTLS Successful 4m
Now first verify if we can connect without using certs.
$ kubectl get secrets -n demo ha-postgres-auth -o jsonpath='{.data.\username}' | base64 -d
postgres
$ kubectl get secrets -n demo ha-postgres-auth -o jsonpath='{.data.\password}' | base64 -d
U6(h_pYrekLZ2OOd
kubectl exec -it -n demo ha-postgres-0 -- bash
Defaulted container "postgres" out of: postgres, pg-coordinator, postgres-init-container (init)
ha-postgres-0:/$ psql -h ha-postgres.demo.svc -U postgres
Password for user postgres:
psql (13.13)
Type "help" for help.
postgres=# SELECT name, setting
postgres-# FROM pg_settings
postgres-# WHERE name IN ('ssl', 'ssl_cert_file', 'ssl_key_file');
name | setting
---------------+------------
ssl | off
ssl_cert_file | server.crt
ssl_key_file | server.key
SSL is off now.
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
kubectl delete postgres -n demo ha-postgres
kubectl delete issuer -n demo pg-issuer pg-new-issuer
kubectl delete postgresopsrequest add-tls remove-tls rotate-tls change-issuer
kubectl delete ns demo
Next Steps
- Detail concepts of Postgres object.
- Monitor your Postgres database with KubeDB using out-of-the-box Prometheus operator.
- Monitor your Postgres database with KubeDB using out-of-the-box builtin-Prometheus.
- Use private Docker registry to deploy Postgres with KubeDB.
- Use kubedb cli to manage databases like kubectl for Kubernetes.
- Detail concepts of Postgres object.
- Want to hack on KubeDB? Check our contribution guidelines.