Add letsencrypt auto renew api

app.py

@@ -9,19 +9,39 @@
 DIR = os.path.dirname(os.path.realpath(__file__))
 ROOT = os.path.join(DIR, 'docs', '_build', 'html')
 
+def find_key(token):
+    if token == os.environ.get("ACME_TOKEN"):
+        return os.environ.get("ACME_KEY")
+    for k, v in os.environ.items():
+        if v == token and k.startswith("ACME_TOKEN_"):
+            n = k.replace("ACME_TOKEN_", "")
+            return os.environ.get("ACME_KEY_{}".format(n))
+
+
 app = Flask(__name__)
+
 if 'DYNO' in os.environ:
-        sslify = SSLify(app)
+    sslify = SSLify(app, skips=['.well-known'])
+
 
 @app.route('/<path:path>')
 def static_proxy(path):
     """Static files proxy"""
     return send_from_directory(ROOT, path)
 
+
 @app.route('/')
 def index_redirection():
     """Redirecting index file"""
     return send_from_directory(ROOT, 'index.html')
 
+
+@app.route("/.well-known/acme-challenge/<token>")
+def acme(token):
+    key = find_key(token)
+    if key is None: abort(404)
+    return key
+
+
 if __name__ == "__main__":
     app.run(debug=True)