Do not override secret key...

modoboa_installer/scripts/modoboa.py

@@ -188,6 +188,14 @@ class Modoboa(base.Installer):
                 "handle_mailboxes": True,
                 "account_auto_removal": True
             },
+            # FIXME: since we rewrite all parameters, the secret key
+            # previously created will disappear. As a quick fix, we
+            # recreate a new one here but it will mess up opened
+            # sessions if the installer is used to upgrade an existing
+            # database...
+            "core": {
+                "secret_key": utils.random_key()
+            },
             "modoboa_amavis": {
                 "am_pdp_mode": "inet",
             },

modoboa_installer/utils.py

@@ -208,3 +208,17 @@ def convert_version_to_int(version):
         number += num << total_bits
         total_bits += bits
     return number
+
+
+def random_key(l=16):
+    """Generate a random key.
+
+    :param integer l: the key's length
+    :return: a string
+    """
+    punctuation = """!#$%&()*+,-./:;<=>?@[]^_`{|}~"""
+    population = string.digits + string.ascii_letters + punctuation
+    while True:
+        key = "".join(random.sample(population * l, l))
+        if len(key) == l:
+            return key