fix: handle empty string

.gitignore

@@ -5,3 +5,5 @@ instance/
 __pycache__/
 signal_targets.txt
 sqlite.db
+substitutions.yaml
+test.env

server/Dockerfile

@@ -14,7 +14,7 @@ RUN python3 -m pip install --no-cache-dir --break-system-packages -r req.txt
 
 # precreate database directory for mount (will otherwise be created at before_first_request)
 COPY ./ .
-RUN mkdir /app/instance/
+RUN mkdir -p /app/instance/
 
 EXPOSE 5000/tcp
 

server/interface.py

@@ -7,6 +7,7 @@ import subprocess
 import os
 import datetime
 import secrets
+import yaml
 
 import ldaptools
 import messagetools
@@ -27,6 +28,16 @@ db = SQLAlchemy(app)
 
 BAD_DISPATCH_ACCESS_TOKEN = "Invalid or missing dispatch-access-token parameter in URL"
 
+def _apply_substitution(string):
+
+    if not string:
+        return string
+
+    for replace, match in app.config["SUBSTITUTIONS"].items():
+        string = string.replace(match, replace)
+
+    return string
+
 class WebHookPaths(db.Model):
 
     __tablename__ = "webhook_paths"
@@ -85,8 +96,8 @@ class DispatchObject(db.Model):
             "timestamp" : self.timestamp,
             "phone" : self.phone,
             "email" : self.email,
-            "title" : self.title,
-            "message" : self.message,
+            "title" : _apply_substitution(self.title),
+            "message" : _apply_substitution(self.message),
             "uuid" : self.dispatch_secret,
             "method" : self.method,
             "error" : self.dispatch_error,
@@ -414,6 +425,15 @@ def create_app():
         app.config["SETTINGS_ACCESS_TOKEN"] = os.environ["SETTINGS_ACCESS_TOKEN"]
         app.config["DISPATCH_ACCESS_TOKEN"] = os.environ["DISPATCH_ACCESS_TOKEN"]
 
+    substitution_config_file = os.environ.get("SUBSTITUTION_MAP") or "substitutions.yaml"
+    app.config["SUBSTITUTIONS"] = {}
+    if os.path.isfile(substitution_config_file):
+        with open(substitution_config_file) as f:
+            app.config["SUBSTITUTIONS"] = yaml.safe_load(f)
+
+    print("Loaded subs:", substitution_config_file, app.config["SUBSTITUTIONS"], file=sys.stderr)
+
+
 if __name__ == "__main__":
 
     parser = argparse.ArgumentParser(description='Simple Telegram Notification Interface',

server/req.txt

@@ -1,4 +1,5 @@
 python-ldap
+pyyaml
 flask
 flask-sqlalchemy
 sqlalchemy