feat: instead of setting environment variables, render input template…

… to output file

with-qubesdb

@@ -1,24 +1,38 @@
 #!/usr/bin/env python3
 import argparse
 import subprocess
+from jinja2 import Template
 
 from qubesdb import QubesDB
 
-if __name__ == "__main__":
-    parser = argparse.ArgumentParser(description="Use -k/--key one or more times to read the specified key from QubesDB.  All subsequent arguments will be interpreted as the command to be invoked with those keys set as environment variables.")
-    parser.add_argument("-k", "--key", action="append")
-    args = parser.parse_known_args()
 
+def get_env(args):
     env = {}
     try:
         db = QubesDB()
-        for key in args[0].key or []:
+        for key in args or []:
             value = db.read(f"/vm-config/{key}")
-            env[key] = value or ''
-
-        if len(args[1]) > 0:
-            cmd = subprocess.Popen(args[1], env=env)
-            cmd.wait()
+            env[key] = (value or "").decode()
 
     finally:
-        db.close()
+        db.close()
+
+    return env
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Use -k/--key one or more times to read the specified key from QubesDB.  The input template will be written to the output file with those variables substituted."
+    )
+    parser.add_argument("-k", "--key", action="append")
+    parser.add_argument("input")
+    parser.add_argument("output")
+    args = parser.parse_args()
+    env = get_env(args.key)
+
+    with open(args.input) as input_f:
+        template = Template(input_f.read())
+
+    with open(args.output, "w") as output_f:
+        rendered = template.render(**env)
+        output_f.write(rendered)