Add ${RANDOM} variable to config file

examples/npbackup.conf.dist

@@ -37,7 +37,10 @@ repo:
 prometheus:
   ## Supervision
   metrics: true
-  backup_job: ${HOSTNAME} # ${HOSTNAME} is a variable which can be replaced with a constant string
+   # ${HOSTNAME} is a variable
+   # ${RANDOM}[n] is a variable containing 'n' random alphanumeric char
+   # The following example allows to have multiple hosts with the same hostname
+  backup_job: ${HOSTNAME}-${RANDOM}
   # Prometheus metrics destination can be a http / https server with optional basic authentication (pushgateway), or a file path for node textfile collector to pickup
   destination: #  https://push.monitoring.example.tld/metrics/job/${BACKUP_JOB} where ${BACKUP_JOB} is defined in prometheus_backup_job
   # prometheus instance, becomes exported_instance when using a push gateway
@@ -65,3 +68,5 @@ options:
   # every 10 NPBackup runs, we'll try an autoupgrade. Never set this lower than 2 since failed upgrades will prevent backups from succeeding
   interval: 10
   backup_admin_password: NPBackup_00
+  # Available variables: ${HOSTNAME}, ${RANDOM}[n]
+  host_identity: ${HOSTNAME}-${RANDOM}[3]

npbackup/configuration.py

@@ -7,15 +7,19 @@ __intname__ = "npbackup.configuration"
 __author__ = "Orsiris de Jong"
 __copyright__ = "Copyright (C) 2022-2023 NetInvent"
 __license__ = "GPL-3.0-only"
-__build__ = "2023020101"
+__build__ = "2023020102"
-__version__ = "1.5.0 for npbackup 2.2.0+"
+__version__ = "1.6.0 for npbackup 2.2.0+"
 
+from typing import Tuple, Optional
 import sys
 from ruamel.yaml import YAML
 from logging import getLogger
+import re
 from cryptidy import symmetric_encryption as enc
+from ofunctions.random import random_string
 from npbackup.customization import ID_STRING
 
+
 # Try to import a private key, if not available, fallback to the default key
 try:
     from npbackup._private_secret_keys import AES_KEY, DEFAULT_BACKUP_ADMIN_PASSWORD
@@ -57,7 +61,7 @@ empty_config_dict = {
 }
 
 
-def decrypt_data(config_dict):
+def decrypt_data(config_dict: dict) -> dict:
     try:
         for option in ENCRYPTED_OPTIONS:
             try:
@@ -95,7 +99,7 @@ def decrypt_data(config_dict):
     return config_dict
 
 
-def encrypt_data(config_dict):
+def encrypt_data(config_dict: dict) -> dict:
     for option in ENCRYPTED_OPTIONS:
         try:
             if config_dict[option["section"]][option["name"]]:
@@ -121,7 +125,7 @@ def encrypt_data(config_dict):
     return config_dict
 
 
-def is_encrypted(config_dict):
+def is_encrypted(config_dict: dict) -> bool:
     try:
         is_enc = True
         for option in ENCRYPTED_OPTIONS:
@@ -142,25 +146,54 @@ def is_encrypted(config_dict):
         # NoneType
         return False
 
+def has_random_variables(config_dict: dict) -> Tuple[bool, dict]:
+    """
+    Replaces ${RANDOM}[n] with n random alphanumeric chars
+    """
+    is_modified = False
+    for section in config_dict.keys():
+        for entry in config_dict[section].keys():
+            if isinstance(config_dict[section][entry], str):
+                matches = re.search(r"\${RANDOM}\[(.*)\]", config_dict[section][entry])
+                print(matches)
+                if matches:
+                    try:
+                        char_quantity = int(matches.group(1))
+                    except (ValueError, TypeError):
+                        char_quantity = 1
+                    print(random_string(char_quantity))
+                    config_dict[section][entry] = re.sub(r"\${RANDOM}\[.*\]", random_string(char_quantity), config_dict[section][entry])
+                    is_modified = True
+    return is_modified, config_dict
 
-def load_config(config_file):
+
+def load_config(config_file: str) -> Optional[dict]:
     """
     Using ruamel.yaml preserves comments and order of yaml files
     """
+    try:
         logger.debug("Using configuration file {}".format(config_file))
         with open(config_file, "r", encoding="utf-8") as file_handle:
             # RoundTrip loader is default and preserves comments and ordering
             yaml = YAML(typ="rt")
             config_dict = yaml.load(file_handle)
+            is_modified, config_dict = has_random_variables(config_dict)
+            if is_modified:
+                logger.info("Handling random variables in configuration files")
+                save_config(config_file, config_dict)
             if not is_encrypted(config_dict):
                 logger.info("Encrypting non encrypted data in configuration file")
                 config_dict = encrypt_data(config_dict)
                 save_config(config_file, config_dict)
             config_dict = decrypt_data(config_dict)
             return config_dict
+    except OSError:
+        logger.critical("Cannot load configuration file from %s", config_file)
+        return None
 
 
-def save_config(config_file, config_dict):
+def save_config(config_file: str, config_dict: dict) -> bool:
+    try:
         with open(config_file, "w", encoding="utf-8") as file_handle:
             if not is_encrypted(config_dict):
                 config_dict = encrypt_data(config_dict)
@@ -168,3 +201,7 @@ def save_config(config_file, config_dict):
             yaml.dump(config_dict, file_handle)
         # Since we deal with global objects in ruamel.yaml, we need to decrypt after saving
         config_dict = decrypt_data(config_dict)
+        return True
+    except OSError:
+        logger.critical("Cannot save configuartion file to %s", config_file)
+        return False

npbackup/requirements.txt

@@ -6,6 +6,7 @@ ofunctions.misc>=1.5.2
 ofunctions.process>=1.4.0
 ofunctions.threading>=2.0.0
 ofunctions.platform>=1.3.0
+ofunctions.random
 python-pidfile>=3.0.0
 pysimplegui>=4.6.0
 requests