Merge branch 'feature-environment' into 'master'

Added environment support

Closes #1

See merge request !1

root/usr/share/teco/pve-ldap-sync

 #!/bin/python3
 # This script is maintained by https://gitlab.teco.edu/it/debian/teco-pve-autoremove-subscription-message
 
-from argparse import ArgumentParser
+from argparse import ArgumentParser, Action
+from os import environ
 from pprint import PrettyPrinter
+
 from ldap import initialize, SCOPE_SUBTREE
 from ldap.ldapobject import LDAPObject
 from proxmoxer import ProxmoxAPI
@@ -16,6 +18,9 @@ ldap_groups = 'ou=Group'
 
 proxmox_host = 'proxmox.teco.edu'
 proxmox_port = '443'
+proxmox_user = None
+proxmox_realm = None
+proxmox_password = None
 proxmox_ssl_check = True
 proxmox_ldap_realm = 'ldap'
 proxmox_ldap_managed_groups = ['IT', 'Staff', 'Students']
@@ -39,6 +44,20 @@ dry_run = False
 be_verbose = False
 
 
+# for parsing environment variables as parameters
+class EnvDefault(Action):
+    def __init__(self, envvar, required=True, default=None, **kwargs):
+        if not default and envvar:
+            if envvar in environ:
+                default = environ[envvar]
+        if required and default:
+            required = False
+        super(EnvDefault, self).__init__(default=default, required=required, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        setattr(namespace, self.dest, values)
+
+
 def log(msg):
     if isinstance(msg, str):
         print(msg)
@@ -51,23 +70,32 @@ def verbose(msg):
         log(msg)
 
 
-def login():
-    global dry_run, be_verbose
+def parse_arguments():
+    global dry_run, be_verbose, proxmox_user, proxmox_realm, proxmox_password
     parser = ArgumentParser(description='Synchronizes the TECO LDAP to the Proxmox User database.')
     parser.add_argument('-u', '--user',
+                        envvar='LDAP_SYNC_PROXMOX_USER',
+                        action=EnvDefault,
                         dest='user',
                         required=True,
                         help='Required argument. Specify the user for Proxmox. '
-                             'The user needs at least PVEUserAdmin role for /access.')
+                             'The user needs at least PVEUserAdmin role for /access. '
+                             'You can also pass this value via LDAP_SYNC_PROXMOX_USER environment variable.')
     parser.add_argument('-r', '--realm',
+                        envvar='LDAP_SYNC_PROXMOX_REALM',
+                        action=EnvDefault,
                         dest='realm',
                         required=True,
-                        help='The Login Realm of the previously specified user')
+                        help='The Login Realm of the previously specified user'
+                             'You can also pass this value via LDAP_SYNC_PROXMOX_REALM environment variable.')
     parser.add_argument('-p', '--password',
+                        envvar='LDAP_SYNC_PROXMOX_PASSWORD',
+                        action=EnvDefault,
                         dest='password',
                         metavar='PASS',
                         required=True,
-                        help='The password for the previously specified user')
+                        help='The password for the previously specified user'
+                             'You can also pass this value via LDAP_SYNC_PROXMOX_PASSWORD environment variable.')
     parser.add_argument('-n', '--dry-run',
                         dest='dry_run',
                         action='store_const',
@@ -83,6 +111,12 @@ def login():
     args = parser.parse_args()
     dry_run = args.dry_run
     be_verbose = args.verbose
+    proxmox_user = args.user
+    proxmox_realm = args.realm
+    proxmox_password = args.password
+
+
+def login():
     verbose('Connecting to LDAP...')
     ldap = initialize(ldap_uri,
                       bytes_mode=False)
@@ -91,8 +125,8 @@ def login():
     proxmox = ProxmoxAPI(host=proxmox_host,
                          backend='https',
                          port=proxmox_port,
-                         user='{}@{}'.format(args.user, args.realm),
-                         password=args.password,
+                         user='{}@{}'.format(proxmox_user, proxmox_realm),
+                         password=proxmox_password,
                          verify_ssl=proxmox_ssl_check)
     verbose('done.')
     return ldap, proxmox
@@ -243,6 +277,7 @@ def sync(proxmox: ProxmoxAPI, ldap_user_dict: dict, proxmox_user_dict: dict):
 
 
 def main():
+    parse_arguments()
     (ldap, proxmox) = login()
     ldap_group_dict: dict = get_ldap_groups(ldap)
     ldap_user_dict: dict = get_ldap_users(ldap, ldap_group_dict)