Skip to content

README.md

Latest commit

 

History

History
60 lines (44 loc) · 1.9 KB

README.md

File metadata and controls

60 lines (44 loc) · 1.9 KB

Example Applications

Minimal Erlang and Elixir applications for testing kubectl-beam.

Short Names vs Long Names

Short names (-sname): Node name without dots (e.g., myapp@podname) Long names (-name): Node name with dots (e.g., myapp@10.244.0.5 or myapp@pod.namespace.svc.cluster.local)

Key differences:

  • Short names work when nodes can find each other without DNS (same network segment)
  • Long names use DNS resolution and work across networks
  • IP addresses contain dots, so they count as long names
  • Nodes with different name types cannot communicate with each other

In Kubernetes, long names are typically preferred since pods get FQDNs via the DNS service.

Structure

examples/
├── erlang-app/          # Rebar3 + relx
├── elixir-app/          # Mix releases
└── k8s/                 # Pod manifests
    ├── erlang-app-name.yaml
    ├── erlang-app-sname.yaml
    ├── elixir-app-name.yaml
    └── elixir-app-sname.yaml

Local Testing

# Setup (requires Docker, kind, kubectl)
./setup-local.sh

# Connect
kubectl beam erl erlang-app-sname --cookie test_cookie_secret
kubectl beam erl erlang-app-name --cookie test_cookie_secret -l
kubectl beam iex elixir-app-sname --cookie test_cookie_secret
kubectl beam iex elixir-app-name --cookie test_cookie_secret -l

# Run integration tests
make test-integration

Configuration

Cookie: test_cookie_secret (set via RELEASE_COOKIE env var) EPMD: Port 4369 Distribution: Ports 9100-9109

Note: Example apps use POD_IP environment variable for the node host part. Since IP addresses contain dots (e.g., 10.244.0.5), they are treated as long names by Erlang. The -sname examples would not work in practice with IP addresses - they're included for testing the kubectl-beam tool only.

Cleanup

kubectl delete -f k8s/
kind delete cluster --name kubectl-beam-test