Debugging Nextcloud slowness My Nextcloud setup is architected as a 3-tier application: it is frontend by a Nginx proxy, served by apache, and data is stored in MySQL, Redis and a NFS server for static files. Problem: Loading the frontpage takes ~10 seconds. Client-side investigation To start the investigation, I opened the network tab of Firefox, and re-loaded the page. Looking at the Timings tab, we can see that the client spent 9.29s waiting for the server. It's a single page proces...

Metallb on Kubernetes NodePorts limitations My original problem was fairly simple: I wanted my kubernetes cluster to serve webpages in HTTPS. I started by running a simple Nginx server in a Pod. Kubernetes would allocate an IP address when creating the pod, but: The IP address was from a private network, which would make it unreachable from the internet. The IP address would change every time I re-created the Pod. Kubernetes solve the second problem with the notion of Service. It is essent...

Debugging IPVS for Kubernetes Symptom A ssh daemon runs in a container called gogs, listening on port 22. A service, also called gogs forwards port 31443 on the node to the internal port 22. However I cannot seem to login using ssh -p 31443 localhost from any kubernetes node. $ k describe service/gogs | grep -A3 "^Port" Port: http 50001/TCP TargetPort: 3000/TCP NodePort: http 31444/TCP Endpoints: 10.244.2.239:3000 Port: ...