adjunctions VS containers

To specify a representing type I can generically derive Representable via More a `ShapedBy` [a].

It worked perfectly for months until this morning, when I woke up to my database in a crashloop and my service completely unavailable. Why? It turns out K8s had to restart the PostgreSQL pod, which then loaded the latest 15.* version of the Docker image. Unfortunately for me, that image was buggy and sent my database down to into oblivion.

[https://github.com/bitnami/containers/tree/main/bitnami/kafka](https://github.com/bitnami/containers/tree/main/bitnami/kafka)

Of course that requires a more complex setup for the database server itself, but thanks to Bitnami's mariadb-galera Docker image and Helm chart, I've managed to get to something rather manageable for our purposes:

If you're writing your own application, it's easy to define different addresses for writing to and reading from a replicated database, respecting the role of each copy. But a lot of useful software already around assumes a single connection is needed, and there's no simple way to get around that. That's why you need specific intermediaries or proxies like Pgpool-II for PostgreSQL, that can appear to applications as a single entity, redirecting queries to the appropriate backend database depending on it's contents:

As mentioned previously, it is based on the one of Bitnami’s containers. Details about environment variables available to be set can be found on Bitnami’s GitHub. Here, we set up the default admin account and database credentials. Additionally, we set the proxy option to "edge" which basically means that communication with Keycloak will happen over HTTP and not over HTTPS protocol. This is acceptable as the Nginx reverse proxy will handle SSL for us.

There are multiple benefits of using the images from Bitnami. We can refer to their github repo for additional details. The Bitnami image from cassandra provides us the option to override few of the configurations in the cassandra.yaml file by passing the values as environment variables. For eg: When we provide an environment variable - CASSANDRA_CLUSTER_NAME – to the container, the value of this variable gets updated in the cassandra.yaml -> cluster_name field.

Have a look at the postgresql readme file to see the value they add: https://github.com/bitnami/containers/tree/main/bitnami/post...

When you use a bunch of different containers from Bitnami, you'll start to notice common configuration patterns which make managing the containers easier.

On the flipside, the additional configuration sometimes contradicts to the official documentation, so that can add complexity from time to time.

https://github.com/bitnami/containers https://bitnami.com/stack/mariadb/containers