feat(decision): add MCP namespace strategy in platform cluster (#13)

* chore: update authors.yaml

* feat(decision): add MCP namespace strategy in platform cluster

* rephrase

Co-authored-by: Valentin Gerlach <valentin.gerlach@sap.com>

* rephrase

Co-authored-by: Valentin Gerlach <valentin.gerlach@sap.com>

* update consequences

Co-authored-by: Valentin Gerlach <valentin.gerlach@sap.com>

* fix: authors file

* fix: complie error because of {}

---------

Co-authored-by: Valentin Gerlach <valentin.gerlach@sap.com>

Author: maximiliantech

adrs/2025-08-12-mcp-namespace-strategy.md

@@ -0,0 +1,27 @@
+---
+authors:
+  - MaximilianTechritz
+---
+
+# MCP Namespace Strategy for Platform Cluster
+
+## Context and Problem Statement
+
+In the openMCP platform, we need to determine how to organize resources in the Platform Cluster that belong to Managed Control Planes (MCPs). Each MCP represents a separate tenant or customer environment that needs to be isolated and managed independently. The key question is: Should every MCP on the Platform Cluster have its own Namespace to ensure proper isolation, resource management, and security boundaries?
+
+Without proper namespace isolation, MCPs could interfere with each other, leading to security vulnerabilities, resource conflicts, and operational complexity.
+
+## Considered Options
+
+1. **`mcp-{hash-mcp-name-and-namespace}`** - Create namespaces using a hash of the MCP name and original namespace (hash < 63 chars)
+2. **`mcp-{uid}`** - Create namespaces using the UID of the MCP resource
+
+## Decision Outcome
+
+Option 1: `mcp-{hash-mcp-name-and-namespace`, because it provides unique namespace isolation for each MCP while avoiding conflicts and maintaining deterministic naming that survives backup/restore operations. Option 2 would have been simpler but does not work well with backup/restore scenarios, as the UID changes after a restore operation, breaking the link between the MCP and its namespace.
+
+The hash algorithm we will use with Option 1 is [SHAKE128](https://pkg.go.dev/crypto/sha3#SumSHAKE128). It is an 128-bit algorithm that is FIPS compliant. The 128-bit output allows us to print the hash in the UUID v8 format. So the namespace could look something like `mcp-3f4b2c1d-8e9a-7b6c-5d4e-3f2a1b0c9d8e`.
+
+### Consequences
+
+- The old hash function `K8sNameHash` should not be used anymore.

adrs/authors.yml

@@ -5,3 +5,10 @@ ValentinGerlach:
   image_url: /img/authors/ValentinGerlach.png
   socials:
     github: ValentinGerlach
+
+MaximilianTechritz:
+  name: Maximilian Techritz
+  title: openMCP Contributor
+  url: https://github.com/maximiliantech
+  socials:
+    github: maximiliantech