Python 3.8 fixes.

README.rst

@@ -30,6 +30,17 @@ Usage::
   $ cd modoboa-installer
   $ sudo ./run.py <your domain>
 
+.. note::
+
+   On some systems (Ubuntu 20.04 for example), you might encounter the
+   following issue::
+
+     /usr/bin/env: 'python': No such file or directory
+
+   If so, try to run the command like this::
+
+     $ sudo python3 run.py <your domain>
+
 A configuration file will be automatically generated the first time
 you run the installer, please don't copy the
 ``installer.cfg.template`` file manually.

modoboa_installer/database.py

@@ -1,7 +1,6 @@
 """Database related tools."""
 
 import os
-import platform
 import pwd
 import stat
 
@@ -143,7 +142,7 @@ class MySQL(Database):
 
     def install_package(self):
         """Preseed package installation."""
-        name, version, _id = platform.linux_distribution()
+        name, version, _id = utils.dist_info()
         name = name.lower()
         if name == "debian":
             mysql_name = "mysql" if version.startswith("8") else "mariadb"

modoboa_installer/scripts/postfix.py

@@ -35,9 +35,9 @@ class Postfix(base.Installer):
     def install_packages(self):
         """Preconfigure postfix package installation."""
         if "centos" in utils.dist_name():
-            config = configparser.SafeConfigParser()
+            config = configparser.ConfigParser()
             with open("/etc/yum.repos.d/CentOS-Base.repo") as fp:
-                config.readfp(fp)
+                config.read_file(fp)
             config.set("centosplus", "enabled", "1")
             config.set("centosplus", "includepkgs", "postfix-*")
             config.set("base", "exclude", "postfix-*")

modoboa_installer/utils.py

@@ -73,17 +73,26 @@ def exec_cmd(cmd, sudo_user=None, pinput=None, login=True, **kwargs):
     return process.returncode, output
 
 
-def dist_name():
-    """Try to guess the distribution name."""
+def dist_info():
+    """Try to return information about the system we're running on."""
     try:
         # Python 3.8 and up way
         import distro
-        name, version, _id = distro.linux_distribution()
-    except ImportError as e:
+        return distro.linux_distribution()
+    except ImportError:
         # Python 3.7 and down way
         import platform
-        name, version, _id = platform.linux_distribution()
-    return "unknown" if not name else name.lower()
+        return platform.linux_distribution()
+    printcolor(
+        "Failed to retrieve information about your system, aborting.",
+        RED)
+    sys.exit(1)
+
+
+def dist_name():
+    """Try to guess the distribution name."""
+    name, version, _id = dist_info()
+    return name.lower()
 
 
 def mkdir(path, mode, uid, gid):

run.py

@@ -79,9 +79,9 @@ def main(input_args):
     utils.check_config_file(args.configfile, args.interactive, args.upgrade)
     if args.stop_after_configfile_check:
         return
-    config = configparser.SafeConfigParser()
+    config = configparser.ConfigParser()
     with open(args.configfile) as fp:
-        config.readfp(fp)
+        config.read_file(fp)
     if not config.has_section("general"):
         config.add_section("general")
     config.set("general", "domain", args.domain)