From 4c37d080146c8661e409ed7d566854dcf9601e74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tam=C3=A1s=20G=C3=A9rczei?= <tamas@gerczei.eu>
Date: Sun, 2 Aug 2020 11:23:16 +0200
Subject: [PATCH] initial prototype

---
 hap.py           | 25 +++++++++++++++++++++++++
 requirements.txt |  1 +
 2 files changed, 26 insertions(+)
 create mode 100755 hap.py
 create mode 100644 requirements.txt

diff --git a/hap.py b/hap.py
new file mode 100755
index 0000000..158e886
--- /dev/null
+++ b/hap.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+# "Have-A-Port" | ephemeral port picker for LoadBalancer-type Kubernetes services in clusters with a single-address external address pool
+from kubernetes import client, config
+import random
+
+SVC_TYPE = 'LoadBalancer'
+
+# load client configuration (kubeconfig)
+config.load_kube_config()
+
+# establish API connection
+connection = client.CoreV1Api()
+# query service objects
+all_services = connection.list_service_for_all_namespaces(watch=False)
+
+# determine ports in use
+ports_per_svc = [ svc.spec.ports for svc in all_services.items if svc.spec.type == SVC_TYPE]
+used_ports = [svc_port.port for svc_ports in ports_per_svc for svc_port in svc_ports]
+
+# determine available ports
+full_port_range = (range(49152, 65536)) # https://tools.ietf.org/html/rfc6335#section-8.1.2
+available_ports = list(set(full_port_range) - set(used_ports))
+
+# pick an available port
+print(random.choice(available_ports))
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..77043e3
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+kubernetes==10.0.1