Update 'Hello Postgres cluster' example to replace deprecated `bitnamilegacy` image

Open running_pg_cluster_in_docker/1. Hello Postgres cluster/docker-compose.yml and inspect the two PostgreSQL service image references. Update both references to soldevelo/postgresql-repmgr:17.6.0, then run the existing Docker Compose example to confirm the cluster still starts with its current configuration.

Hi,

I was exploring your excellent collection of SQL scripts and Docker examples, and I noticed that the running_pg_cluster_in_docker/1. Hello Postgres cluster/docker-compose.yml file uses the bitnamilegacy/postgresql-repmgr:17.6.0 Docker image.

The Problem
As the namespace implies, bitnamilegacy contains deprecated artifacts that are no longer actively maintained. Using this legacy repository in an educational/reference example is risky because these images do not receive necessary updates or CVE security patches. Users copying this docker-compose.yml for their own projects will unknowingly deploy an unmaintained database cluster.

Proposed Solution
I suggest switching to soldevelo/postgresql-repmgr.
This image is a free, actively maintained, and fully open-source drop-in replacement.

Crucially, it is perfectly compatible with your current example:

• It preserves the exact same environment variables, repmgr logic, and internal paths.
• Your Docker Compose setup will continue to work immediately without any structural changes, but it will be backed by a secure, actively supported image.

(Note: SolDevelo maintains a growing library of open-source, Bitnami-compatible images to help the community move away from deprecated or paywalled artifacts. You can find the source code and other images here: https://github.com/SolDevelo/containers)

Suggested Changes in running_pg_cluster_in_docker/1. Hello Postgres cluster/docker-compose.yml:

# Old
    container_name: postgres_1
    image: docker.io/bitnamilegacy/postgresql-repmgr:17.6.0
...
    container_name: postgres_2
    image: docker.io/bitnamilegacy/postgresql-repmgr:17.6.0

# New
    container_name: postgres_1
    image: docker.io/soldevelo/postgresql-repmgr:17.6.0
...
    container_name: postgres_2
    image: docker.io/soldevelo/postgresql-repmgr:17.6.0

I would be happy to submit a Pull Request to update this reference so your example remains robust and follows best security practices. Would you be open to that?