ADR 0031 - Naming scheme for Servala cluster names and URLs

Author

Nicolas Bigler

Owner

Schedar

Reviewers

Date Created

2025-04-11

Date Updated

2025-04-11

Status

draft

Tags

servala,naming,scheme,cluster
Summary

With the launch of Servala we will have multiple clusters running on different cloud providers and on different regions. To ensure consistency and ease of management, it is important to establish a naming scheme for these clusters. This ADR outlines the proposed naming scheme for Servala cluster names and URLs.

Context

Cluster names

We have two different kind of clusters for Servala: * Control-plane clusters: Those run Crossplane and contain all the Crossplane resources like functions, composites, api-server etc. * Service clusters: Those run the workloads that are managed by Crossplane.

To properly distinguish and identify each cluster, the cluster name should contain the following information: * The CSP where the cluster is running: Cloudscale, Exoscale, etc. * The region where the cluster is running: ch-gva-2, lpg1, etc. * The type of cluster: control or service * The stage of the cluster: test, prod * A counter for each cluster to ensure uniqueness.

Lieutenant already gives us part of the naming scheme. Each cluster should be prefixed with c- followed by the tenant, so that it’s easy for users to identify which tenant owns the cluster.

URLs

We have two different URLs that are important: * The Kubernetes API endpoint * The apps endpoint of OpenShift for applications on the service clusters

The defaults in OpenShift are:

  • api.[clustername].domain.tld

  • *.apps.[clustername].domain.tld

Decision

Cluster names

Putting all the information above together we propose the following naming scheme for Servala cluster names:

c-servala-[TYPE]-[CSP]-[REGION]-[STAGE][COUNTER]

TYPE

The type of the cluster. control or service

CSP

The CSP where the cluster is running. cloudscale, exoscale, etc.

REGION

The region on the CSP where the cluster is running. ch-gva-2, lpg1, etc. Use the same naming as the CSP.

STAGE

The stage of the cluster. test, prod, etc

COUNTER

A unique counter for each cluster

Examples:

  • First production control-plane cluster running on Cloudscale in the lpg1 zone: c-servala-control-cloudscale-lpg1-prod1

  • Second test service cluster running on Exoscale in the ch-gva-2 region: c-servala-service-exoscale-ch-gva-2-test2

URLs

We have a dedicated domain for servala clusters: servala.com and will use that domain for all clusters

The control-plane clusters API should be reachable under the following URL: api.[csp]-[region]-[stage][counter].control.servala.com

The apps domain for the services should be: *.apps.[csp]-[region]-[stage][counter].servala.com

Examples:

  • First production control-plane cluster running on Cloudscale in the lpg1 region: api.cloudscale-lpg1-prod1.control.servala.com

  • Second test service cluster running on Exoscale in the ch-gva-2 region: api.exoscale-ch-gva-2-test2.control.servala.com