Charmed PostgreSQL VM Tutorial > 6. Enable security

Enable security with TLS

Transport Layer Security (TLS) is a protocol used to encrypt data exchanged between two applications. Essentially, it secures data transmitted over a network.

Typically, enabling TLS internally within a highly available database or between a highly available database and client/server applications requires a high level of expertise. This has all been encoded into Charmed PostgreSQL so that configuring TLS requires minimal effort on your end.

TLS is enabled by integrating Charmed PostgreSQL with the Self Signed Certificates Charm. This charm centralises TLS certificate management consistently and handles operations like providing, requesting, and renewing TLS certificates.

In this section, you will learn how to enable security in your PostgreSQL deployment using TLS encryption.

Configure TLS

Before enabling TLS on Charmed PostgreSQL VM, we must deploy the self-signed-certificates charm:

juju deploy self-signed-certificates --config ca-common-name="Tutorial CA"

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

Model     Controller  Cloud/Region         Version  SLA          Timestamp
tutorial  overlord    localhost/localhost  3.1.7    unsupported  10:31:40+01:00

App                        Version  Status  Scale  Charm                      Channel    Rev  Exposed  Message
postgresql                          active      2  postgresql                 14/stable  281  no       
self-signed-certificates            active      1  self-signed-certificates   stable     72   no       

Unit                          Workload  Agent  Machine  Public address  Ports  Message
postgresql/0*                 active    idle   0        10.89.49.129           Primary
postgresql/1                  active    idle   1        10.89.49.197           
self-signed-certificates/0*   active    idle   3        10.89.49.185           

Machine  State    Address       Inst id        Series  AZ  Message
0        started  10.89.49.129  juju-a8a31d-0  jammy       Running
1        started  10.89.49.197  juju-a8a31d-1  jammy       Running
4        started  10.89.49.185  juju-a8a31d-3  jammy       Running

Add external TLS certificate

To enable TLS on Charmed PostgreSQL VM, integrate the two applications:

juju integrate postgresql self-signed-certificates

Check the TLS certificate in use:

Use openssl to connect to the PostgreSQL and check the TLS certificate in use. Note that your leader unit’s IP address will likely be different to the one shown below:

> openssl s_client -starttls postgres -connect 10.89.49.129:5432 | 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 self-signed-certificates.

Remove external TLS certificate

To remove the external TLS, remove the integration:

juju remove-relation postgresql self-signed-certificates

Check the TLS certificate in use:

> openssl s_client -starttls postgres -connect 10.89.49.129:5432
...
no peer certificate available
---
No client certificate CA names sent
...

The Charmed PostgreSQL VM application is not using TLS anymore.