Add letsencrypt support in the nginx container

nginx/Dockerfile

@@ -1,8 +1,8 @@
 FROM alpine:edge
 
-RUN apk add --no-cache nginx nginx-mod-mail python py-jinja2
+RUN apk add --no-cache nginx nginx-mod-mail python py-jinja2 certbot openssl
 
 COPY conf /conf
-COPY start.py /start.py
+COPY *.py /
 
 CMD /start.py

nginx/conf/nginx.conf

@@ -21,7 +21,8 @@ http {
     server {
       listen 80;
 
-      {% if TLS_FLAVOR != 'notls' %}
+      # TLS configuration
+      {% if TLS and not TLS_ERROR %}
       listen 443 ssl;
 
       ssl_protocols TLSv1.1 TLSv1.2;
@@ -29,8 +30,8 @@ http {
       ssl_prefer_server_ciphers on;
       ssl_session_timeout 5m;
       ssl_session_cache shared:SSL:50m;
-      ssl_certificate /certs/cert.pem;
-      ssl_certificate_key /certs/key.pem;
+      ssl_certificate {{ TLS[0] }};
+      ssl_certificate_key {{ TLS[1] }};
 
       add_header Strict-Transport-Security max-age=15768000;
 
@@ -39,7 +40,18 @@ http {
       }
       {% endif %}
 
+      {% if TLS_FLAVOR == 'letsencrypt' %}
+      location ^~ /.well-known/acme-challenge/ {
+          proxy_pass http://localhost:8000;
+      }
+      {% endif %}
+
       # Actual logic
+      {% if TLS_ERROR %}
+      location / {
+        return 403
+      }
+      {% else %}
       {% if WEBMAIL != 'none' %}
       location / {
         return 301 $scheme://$host/webmail/;
@@ -52,6 +64,9 @@ http {
       {% endif %}
 
       {% if ADMIN == 'true' %}
+      location /admin {
+        return 301 $scheme://$host/admin/ui;
+      }
       location /admin/ui {
         rewrite ^/admin/(.*) /$1 break;
         proxy_pass http://admin;
@@ -64,11 +79,12 @@ http {
         proxy_pass http://webdav:5232;
       }
       {% endif %}
+      {% endif %}
     }
 }
 
 mail {
-    server_name {{ HOSTNAME }};
+    server_name {{ HOSTNAMES.split(",")[0] }};
     auth_http http://{{ ADMIN_ADDRESS }}/internal/nginx;
     proxy_pass_error_message on;
 

nginx/config.py

@@ -0,0 +1,27 @@
+#!/usr/bin/python
+
+import jinja2
+import os
+import socket
+	
+convert = lambda src, dst, args: open(dst, "w").write(jinja2.Template(open(src).read()).render(**args))
+
+args = os.environ.copy()
+
+if "ADMIN_ADDRESS" not in os.environ:
+    args["ADMIN_ADDRESS"] = socket.gethostbyname("admin")
+
+args["TLS"] = {
+    "cert": ("/certs/cert.pem", "/certs/key.pem"),
+    "letsencrypt": ("/certs/letsencrypt/live/mailu/fullchain.pem",
+        "/certs/letsencrypt/live/mailu/privkey.pem"),
+    "notls": None
+}[args["TLS_FLAVOR"]]
+
+if args["TLS"] and not all(os.path.exists(file_path) for file_path in args["TLS"]):
+    print("Missing cert or key file, disabling TLS")
+    args["TLS_ERROR"] = "yes"
+
+
+convert("/conf/nginx.conf", "/etc/nginx/nginx.conf", args)
+os.system("nginx -s reload")

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)
+

nginx/start.py

@@ -1,13 +1,15 @@
 #!/usr/bin/python
 
-import jinja2
 import os
-import socket
-	
-convert = lambda src, dst: open(dst, "w").write(jinja2.Template(open(src).read()).render(**os.environ))
+import subprocess
+
 
 # Actual startup script
-if "ADMIN_ADDRESS" not in os.environ:
-    os.environ["ADMIN_ADDRESS"] = socket.gethostbyname("admin")
-convert("/conf/nginx.conf", "/etc/nginx/nginx.conf")
+if not os.path.exists("/certs/dhparam.pem") and os.environ["TLS_FLAVOR"] != "notls":
+    os.system("openssl dhparam -out /certs/dhparam.pem 4096")
+
+if os.environ["TLS_FLAVOR"] == "letsencrypt":
+    subprocess.Popen(["/letsencrypt.py"])
+
+subprocess.call(["/config.py"])
 os.execv("/usr/sbin/nginx", ["nginx", "-g", "daemon off;"])