Add letsencrypt support in the nginx container

nginx/letsencrypt.py

@@ -0,0 +1,29 @@
+#!/usr/bin/python
+
+import os
+import time
+import subprocess
+
+
+command = [
+    "certbot",
+    "-n", "--agree-tos", # non-interactive
+    "-d", os.environ["HOSTNAMES"],
+    "-m", "{}@{}".format(os.environ["POSTMASTER"], os.environ["DOMAIN"]),
+    "certonly", "--standalone",
+    "--cert-name", "mailu",
+    "--preferred-challenges", "http", "--http-01-port", "8000",
+    "--keep-until-expiring",
+    "--rsa-key-size", "4096",
+    "--config-dir", "/certs/letsencrypt",
+    "--post-hook", "/config.py"
+]
+
+# Wait for nginx to start
+time.sleep(5)
+
+# Run certbot every hour
+while True:
+    subprocess.call(command)
+    time.sleep(3600)
+