chore: prevent installing recommended packages (e.g. installing cron leads to installing exim without it).

cmdeploy/src/cmdeploy/deployers.py

@@ -6,7 +6,7 @@ import os
 import shutil
 import subprocess
 import sys
-from io import StringIO
+from io import BytesIO, StringIO
 from pathlib import Path
 
 from chatmaild.config import read_config
@@ -478,6 +478,14 @@ class ChatmailDeployer(Deployer):
         self.mail_domain = mail_domain
 
     def install(self):
+        files.put(
+            name="Disable installing recommended packages globally",
+            src=BytesIO(b'APT::Install-Recommends "false";\n'),
+            dest="/etc/apt/apt.conf.d/00InstallRecommends",
+            user="root",
+            group="root",
+            mode="644",
+        )
         apt.update(name="apt update", cache_time=24 * 3600)
         apt.upgrade(name="upgrade apt packages", auto_remove=True)