From 71c8709d47edc937c35a210f3fa7bf5171e88909 Mon Sep 17 00:00:00 2001
From: Florian Paul Azim Hoberg <gyptazy@gyptazy.ch>
Date: Fri, 12 Jul 2024 13:55:17 +0200
Subject: [PATCH] feature(API): Add ProxLB API

Fixes: #8
---
 proxlb           | 80 +++++++++++++++++++++++++++++++++++++++++++++++-
 requirements.txt |  6 +++-
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/proxlb b/proxlb
index 57aa7a3..5825b49 100755
--- a/proxlb
+++ b/proxlb
@@ -22,6 +22,11 @@
 
 import argparse
 import configparser
+try:
+    import http.server
+    _api_ = True
+except:
+    _api_ = False
 import json
 import logging
 import os
@@ -35,6 +40,7 @@ import re
 import requests
 import sys
 import time
+import threading
 import urllib3
 
 
@@ -45,6 +51,9 @@ __author__  = "Florian Paul Azim Hoberg <gyptazy@gyptazy.ch> @gyptazy"
 __errors__ = False
 
 
+# Global Vars
+node_statistics_rebalanced = {}
+
 # Classes
 ## Logging class
 class SystemdHandler(logging.Handler):
@@ -71,6 +80,38 @@ class SystemdHandler(logging.Handler):
             self.handleError(record)
 
 
+class ProxLBAPIHandler(http.server.BaseHTTPRequestHandler):
+    """ Class to handle ProxLB API requests. """
+    def do_GET(self):
+        self.send_response(200)
+        self.send_header('Content-type', 'text/html')
+        self.send_header(__appname__, __version__)
+        self.end_headers()
+
+        if self.path == '/health':
+            http_content = '{"healthy": True, "action": True}'
+            
+            self.wfile.write(http_content.encode('utf-8'))
+
+        elif self.path == '/cluster/placement/nextnode':
+            self.wfile.write(json.dumps(global_nextnode).encode('utf-8'))
+
+        elif self.path == '/cluster/placement/statistics/current/vms':
+            self.wfile.write(json.dumps(global_vm_statistics).encode('utf-8'))
+
+        elif self.path == '/cluster/placement/statistics/current/nodes':
+            self.wfile.write(json.dumps(global_node_statistics).encode('utf-8'))
+
+        elif self.path == '/cluster/placement/statistics/rebalanced/vms':
+            self.wfile.write(json.dumps(global_vm_statistics_rebalanced).encode('utf-8'))
+
+        elif self.path == '/cluster/placement/statistics/rebalanced/nodes':
+            self.wfile.write(json.dumps(global_node_statistics_rebalanced).encode('utf-8'))
+
+        else:
+            http_content = '{"action": False}'
+            self.wfile.write(http_content.encode('utf-8'))
+
 # Functions
 def initialize_logger(log_level, log_handler):
     """ Initialize ProxLB logging handler. """
@@ -195,6 +236,38 @@ def initialize_config_options(config_path):
     return proxmox_api_host, proxmox_api_user, proxmox_api_pass, proxmox_api_ssl_v, balancing_method, \
          balanciness, ignore_nodes, ignore_vms, daemon, schedule
 
+def create_global_vars(node_statistics, vm_statistics, node_statistics_rebalanced,
+                        vm_statistics_rebalanced, balancing_method, balanciness):
+    """ Create global variables for ProxLB API. """
+    global global_node_statistics
+    global global_vm_statistics
+    global global_node_statistics_rebalanced
+    global global_vm_statistics_rebalanced
+    global global_balancing_method
+    global global_balanciness
+    global global_nextnode
+
+    global_node_statistics            = node_statistics
+    global_vm_statistics              = vm_statistics
+    global_node_statistics_rebalanced = node_statistics_rebalanced
+    global_vm_statistics_rebalanced   = vm_statistics_rebalanced
+    global_balancing_method           = balancing_method
+    global_balanciness                = balanciness
+    global_nextnode                   = __get_most_free_resources_node(balancing_method, node_statistics)
+
+
+def initialize_proxlb_api(_api_):
+    """ Initialize ProxLB API endpoint. """
+    error_prefix = 'Error: [proxlb-api]:'
+    info_prefix  = 'Info: [proxlb-api]:'
+
+    logging.info(f'{info_prefix} Starting ProxLB API endpoint.')
+    try:
+        httpd = http.server.HTTPServer(('0.0.0.0', 9091), ProxLBAPIHandler)
+        httpd.serve_forever()
+    except:
+        logging.critical(f'{error_prefix} ProxLB API could not be started.')
+
 
 def api_connect(proxmox_api_host, proxmox_api_user, proxmox_api_pass, proxmox_api_ssl_v):
     """ Connect and authenticate to the Proxmox remote API. """
@@ -602,7 +675,7 @@ def print_table_cli(table):
 def main():
     """ Run ProxLB for balancing VM workloads across a Proxmox cluster. """
     # Initialize PAS.
-    initialize_logger('CRITICAL', 'SystemdHandler()')
+    initialize_logger('INFO', 'SystemdHandler()')
     app_args = initialize_args()
     config_path = initialize_config_path(app_args)
     pre_validations(config_path)
@@ -628,6 +701,11 @@ def main():
         # Validate for any errors
         post_validations()
 
+        # Start ProxLB API
+        if _api_:
+            create_global_vars(node_statistics, vm_statistics, node_statistics_rebalanced, vm_statistics_rebalanced, balancing_method, balanciness)
+            threading.Thread(target=initialize_proxlb_api(_api_), name="ProxLB_API").start()
+
         # Validate daemon service
         validate_daemon(daemon, schedule)
 
diff --git a/requirements.txt b/requirements.txt
index 4adb81f..215313b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,9 @@
 argparse
 configparser
+http.server
+json
 proxmoxer
+random
 requests
-urllib3
\ No newline at end of file
+threading
+urllib3