From 061916c1d5576526b2c45509986e22a325087bf1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauri=20V=C3=B5sandi?= <lauri@k-space.ee>
Date: Wed, 21 Sep 2022 12:35:12 +0300
Subject: [PATCH] Initial commit

---
 .drone.yml      |  2 ++
 Dockerfile      |  3 ++
 README.md       |  3 ++
 bind-sidecar.py | 89 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 97 insertions(+)
 create mode 100644 .drone.yml
 create mode 100644 Dockerfile
 create mode 100644 README.md
 create mode 100755 bind-sidecar.py

diff --git a/.drone.yml b/.drone.yml
new file mode 100644
index 0000000..e7b5dfa
--- /dev/null
+++ b/.drone.yml
@@ -0,0 +1,2 @@
+kind: template
+load: docker.yaml
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..973f069
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,3 @@
+FROM harbor.k-space.ee/k-space/microservice-base
+ADD bind-sidecar.py /
+ENTRYPOINT /bind-sidecar.py
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a93426c
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# Meta operator
+
+Meta operator allows creating operators without building any binaries
diff --git a/bind-sidecar.py b/bind-sidecar.py
new file mode 100755
index 0000000..f23204b
--- /dev/null
+++ b/bind-sidecar.py
@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+import asyncio
+import ecs_logging
+import logging
+import os
+import sys
+from kubernetes_asyncio.client.api_client import ApiClient
+from kubernetes_asyncio import client, config, watch
+from time import time
+
+# Get the Logger
+logger = logging.getLogger()
+logger.setLevel(logging.INFO)
+
+# Add an ECS formatter to the Handler
+handler = logging.StreamHandler()
+handler.setFormatter(ecs_logging.StdlibFormatter())
+logger.addHandler(handler)
+
+ZONEFILE_TEMPLATE = """
+@ IN SOA ns1.%(zone)s. hostmaster.%(zone)s. (2022060820 300 300 300 300)
+    NS ns1.%(zone)s.
+ns1 A  %(ip)s
+"""
+
+_, ip = sys.argv
+
+PATH_CONFIG = "/var/bind/bind.conf"
+PATH_ZONEFILE = "/var/bind/db.%s"
+
+active_zones = set()
+
+
+def update_config():
+    with open(PATH_CONFIG + ".part", "w") as fh:
+        for zone in active_zones:
+            path = PATH_ZONEFILE % zone
+            fh.write("zone \"%s\" { type master; file \"%s\"; };\n" % (zone, path))
+    os.rename(PATH_CONFIG + ".part", PATH_CONFIG)
+
+
+async def update_loop(v1, apps_api, api_instance, revision):
+    flt = "codemowers.io", "v1alpha1", "bindzones"
+    method = api_instance.list_cluster_custom_object
+    w = watch.Watch()
+    latest_version = None
+    logger.info("Subscribing to updates")
+    async for event in w.stream(method, *flt, resource_version=latest_version):
+        latest_version = event["object"]["metadata"]["resourceVersion"]
+        if event["type"] == "ADDED":
+            zone = event["object"]["metadata"]["name"]
+            active_zones.add(zone)
+            path = PATH_ZONEFILE % zone
+            logger.info("Adding zone: %s", zone)
+            if not os.path.exists(path):
+                with open(path + ".part", "w") as fh:
+                    fh.write(ZONEFILE_TEMPLATE % {
+                        "ip": ip,
+                        "zone": zone
+                    })
+                os.rename(path + ".part", path)
+            update_config()
+        elif event["type"] == "DELETED":
+            logger.info("Removing zone: %s", zone)
+            active_zones.remove(zone)
+            os.unlink(PATH_ZONEFILE % event["object"]["metadata"]["name"])
+
+
+async def main():
+    if os.getenv("KUBECONFIG"):
+        await config.load_kube_config()
+    else:
+        config.load_incluster_config()
+    async with ApiClient() as api:
+        v1 = client.CoreV1Api(api)
+        apps_api = client.AppsV1Api()
+        api_instance = client.CustomObjectsApi(api)
+        revision = str(time())
+        while True:
+            try:
+                await update_loop(v1, apps_api, api_instance, revision)
+            except asyncio.exceptions.TimeoutError:
+                pass
+
+
+if __name__ == "__main__":
+    loop = asyncio.new_event_loop()
+    loop.run_until_complete(main())
+    loop.close()