First working certificate generation code, related to #35

admin/Dockerfile

@@ -10,6 +10,13 @@ COPY requirements.txt .
 COPY start.sh /start.sh
 
 RUN pip install -r requirements.txt
+
+# Temporarily install certbot from source while waiting for 0.10
+RUN git clone https://github.com/certbot/certbot /certbot \
+ && cd /certbot \
+ && pip install -e ./acme \
+ && pip install -e ./
+
 RUN pybabel compile -d mailu/translations
 
 CMD ["/start.sh"]

admin/mailu/__init__.py

@@ -28,7 +28,9 @@ default_config = {
     'DKIM_PATH': '/dkim/{domain}.{selector}.key',
     'DKIM_SELECTOR': 'dkim',
     'BABEL_DEFAULT_LOCALE': 'en',
-    'BABEL_DEFAULT_TIMEZONE': 'UTC'
+    'BABEL_DEFAULT_TIMEZONE': 'UTC',
+    'ENABLE_CERTBOT': False,
+    'CERTS_PATH': '/certs'
 }
 
 # Load configuration from the environment if available
@@ -61,6 +63,10 @@ if not app.debug or os.environ.get('WERKZEUG_RUN_MAIN') == 'true':
 def get_locale():
     return flask.request.accept_languages.best_match(translations)
 
+# Certbot configuration
+if app.config['ENABLE_CERTBOT']:
+    from mailu import certbot
+
 # Finally setup the blueprint and redirect /
 from mailu import admin
 app.register_blueprint(admin.app, url_prefix='/admin')

admin/mailu/certbot.py

@@ -0,0 +1,68 @@
+from mailu import app, scheduler
+
+import subprocess
+import os
+
+
+def certbot_command(subcommand, *args):
+    """ Run a certbot command while specifying the standard parameters.
+    """
+    command = [
+        "certbot", subcommand,
+        "-n",
+        "--work-dir", "/tmp",
+        "--logs-dir", "/tmp",
+        "--config-dir", app.config["CERTS_PATH"],
+        *args
+    ]
+    result = subprocess.run(command, stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE)
+    return result
+
+
+def certbot_install(domain):
+    """ Install certificates for the given domain. Return True if a reload
+    is required.
+    """
+    must_reload = False
+    path = app.config["CERTS_PATH"]
+    cert = os.path.join(path, "cert.pem")
+    key = os.path.join(path, "key.pem")
+    live_cert = os.path.join(path, "live", domain, "fullchain.pem")
+    live_key = os.path.join(path, "live", domain, "privkey.pem")
+    if not os.path.islink(cert) or os.readlink(cert) != live_cert:
+        must_reload = True
+        os.unlink(cert)
+        os.symlink(live_cert, cert)
+    if not os.path.islink(key) or os.readlink(key) != live_key:
+        must_reload = True
+        os.unlink(key)
+        os.symlink(live_key, key)
+    return must_reload
+
+
+@scheduler.scheduled_job('date')
+@scheduler.scheduled_job('cron', hour=2, minute=0)
+def generate_cert():
+    print("Generating TLS certificates using Certbot")
+    domain = app.config["DOMAIN"]
+    email = "{}@{}".format(app.config["POSTMASTER"], domain)
+    result = certbot_command(
+        "certonly",
+        "--standalone",
+        "--agree-tos",
+        "--preferred-challenges", "http",
+        "--email", email,
+        "-d", domain,
+        # The port is hardcoded in the nginx image as well, we should find
+        # a more suitable way to go but this will do until we have a proper
+        # daemon handling certbot stuff
+        "--http-01-port", "8081"
+    )
+    if result.returncode:
+        print("Error while generating certificates:\n{}".format(
+            result.stdout.decode("utf8") + result.stdout.decode("utf8")))
+    else:
+        print("Successfully generated or renewed TLS certificates")
+        must_reload = certbot_install(domain)
+        

admin/run.py

@@ -2,6 +2,6 @@ import os
 
 
 if __name__ == "__main__":
-    os.environ["DEBUG"] = "true"
+    os.environ["DEBUG"] = "True"
     from mailu import app
     app.run()

nginx/nginx.conf

@@ -76,5 +76,9 @@ http {
           return 403;
         }
       }
+
+      location /.well-known/acme-challenge {
+        proxy_pass http://admin:8081;
+      }
     }
 }