Add HELM Chart

[24367dfa]

I would like to contribute a helm chart for cleanURI. Do you have any preferences on the organization of the HELM Chart?

[penguineer]

I like the way Bitnami charts are organized (esp. with respect to the configuration).

Assumptions (or at least very likely config structures) you can make:

• The RabbitMQ deployment is external and can be expected to be available.
• Direct Queuing, i.e. output queue of one service will be input queue of another service. Ideally: If input is not defined, take the output as a default.
• Shared RabbitMQ account secrets, or a common secret as default when deviations are not specified
• Only the API Gateway will ever expose a REST API, the other components communicate via RabbitMQ.

The cut of the components is based on expected scaling, if this were a big deployment.

At some point there will be a Redis-based cache component, but not yet. Redis will also be expected to be deployed externally.

As there is no persistence layer involved, the Micronaut components start very fast (< 1s) on my machine.

[penguineer]

The component versions are a moving target. It should be easy to update and adjust them.

[24367dfa]

@penguineer Should the helm chart render a configmap for each component oder do you prefer setting the environment variables directly inside the deployment?

and would you prefer a generic sub-chart, that gets configured for each component (see https://helm.sh/docs/topics/charts/#the-chartyaml-file) or a dedicated subchart for each component?