Added comprehensive documentation of the two-tier load balancing setup:
- Hetzner Cloud Load Balancer (external layer, managed by Hetzner CCM)
- Kubernetes LoadBalancer services (internal layer, k3s ServiceLB)
Key points documented:
- Traffic flow from external client through both LB layers to pod
- Why LoadBalancer service type is required (CCM integration)
- Historical context of the migration from hostPort to Hetzner LB
- Service definitions and port configurations
Updated:
- apps/stalwart/README.md: Added Network Architecture section
- infrastructure/networking/NETWORK_ARCHITECTURE.md: Enhanced Stalwart
section with two-tier architecture details and updated traffic flows
Resolves documentation gap identified in DEV-439.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
Add comprehensive Network Architecture section explaining:
- Two-tier load balancing (K8s LoadBalancer + Hetzner LB)
- Why LoadBalancer service type is required (Hetzner CCM auto-management)
- Traffic flow from external clients to Stalwart pods
- Warning against changing to NodePort (breaks CCM integration)
This documents the investigation from DEV-439, confirming that the current
LoadBalancer service setup is correct and necessary for our infrastructure.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
Extends commit 291feb9 by adding stalwart-config (stalwart.toml) to the
copy-config initContainer. The previous fix only handled bootstrap-config
but missed stalwart-config, which was the root cause of CrashLoopBackOff
identified in DEV-426 stability testing.
Root cause: commit 693fcd3 introduced stalwart-config ConfigMap with
subPath mount. During pod restarts, Kubernetes subPath ConfigMap mounting
race leaves stalwart.toml empty/unparseable, causing:
"Failed to parse data store settings at /etc/stalwart/stalwart.toml:
expected value at line 1 column 1"
This completes the hardening by ensuring BOTH config files (config.json
and stalwart.toml) are atomically copied before Stalwart starts.
Fixes: DEV-433, DEV-431
Ref: stack.basicstack.de/apps/stalwart/STABILITY-VERIFICATION-2026-08-01.md
Co-Authored-By: Paperclip <noreply@paperclip.ing>
