Charmed PostgreSQL K8s

  • By Canonical Data Platform
Channel Revision Published Runs on
latest/stable 20 20 Sep 2022
Ubuntu 20.04
14/stable 73 18 Apr 2023
Ubuntu 22.04
14/candidate 73 18 Apr 2023
14/beta 73 18 Apr 2023
14/edge 92 Yesterday
juju deploy postgresql-k8s --channel 14/stable
Show information


Enable Security in your PostgreSQL deployment

This is part of the Charmed PostgreSQL Tutorial. Please refer to this page for more information and the overview of the content.

Transport Layer Security (TLS)

TLS is used to encrypt data exchanged between two applications; it secures data transmitted over the network. Typically, enabling TLS within a highly available database, and between a highly available database and client/server applications, requires domain-specific knowledge and a high level of expertise. Fortunately, the domain-specific knowledge has been encoded into Charmed PostgreSQL K8s. This means (re-)configuring TLS on Charmed PostgreSQL K8s is readily available and requires minimal effort on your end.

Again, relations come in handy here as TLS is enabled via relations; i.e. by relating Charmed PostgreSQL K8s to the TLS Certificates Charm. The TLS Certificates Charm centralises TLS certificate management in a consistent manner and handles providing, requesting, and renewing TLS certificates.

Configure TLS

Before enabling TLS on Charmed PostgreSQL K8s we must first deploy the tls-certificates-operator charm:

juju deploy tls-certificates-operator --config generate-self-signed-certificates="true" --config ca-common-name="Tutorial CA"

Wait until the tls-certificates-operator is up and active, use juju status --watch 1s to monitor the progress:

Model     Controller  Cloud/Region        Version  SLA          Timestamp
tutorial  charm-dev   microk8s/localhost  2.9.42   unsupported  12:18:05+01:00

App                        Version  Status   Scale  Charm                      Channel    Rev  Address         Exposed  Message
postgresql-k8s                      active       2  postgresql-k8s             14/stable  56  no
tls-certificates-operator           waiting      1  tls-certificates-operator  stable     22  no       installing agent

Unit                          Workload    Agent  Address       Ports  Message
postgresql-k8s/0*             active      idle         Primary
postgresql-k8s/1              active      idle
tls-certificates-operator/0*  active      idle

Note: this tutorial uses self-signed certificates; self-signed certificates should not be used in a production cluster.

To enable TLS on Charmed PostgreSQL K8s, relate the two applications:

juju relate postgresql-k8s tls-certificates-operator

Add external TLS certificate

Use openssl to connect to the PostgreSQL and check the TLS certificate in use:

> openssl s_client -starttls postgres -connect | grep Issuer
depth=1 C = US, CN = Tutorial CA
verify error:num=19:self-signed certificate in certificate chain

Congratulations! PostgreSQL is now using TLS certificate generated by the external application tls-certificates-operator.

Remove external TLS certificate

To remove the external TLS and return to the locally generate one, unrelate applications:

juju remove-relation postgresql-k8s tls-certificates-operator

Check the TLS certificate in use:

> openssl s_client -starttls postgres -connect
no peer certificate available
No client certificate CA names sent

The Charmed PostgreSQL K8s application is not using TLS anymore.

Help us improve this documentation

Most of this documentation can be collaboratively discussed and changed on the respective topic in the doc category of the Charmhub forum. See the documentation guidelines if you’d like to contribute.

Last updated a month ago. Help improve this document in the forum.