feat: add Consul-based global ID generator with fallback mechanism

Co-authored-by: aider (openrouter/openai/o3-mini-high) <aider@aider.chat>

amqp/service/consul_global_id_generator.py

@@ -95,3 +95,110 @@ def get_unique_instance_id() -> int:
         logger.error(f"Could not connect to Consul or an unexpected error occurred: {e}")
         return generate_fallback_id()  # Fallback if Consul is completely unreachable
 
+import os
+import logging
+import random
+import socket
+import time
+from typing import Optional
+
+import consul
+
+# Configuration from environment variables with defaults
+CONSUL_HOST = os.environ.get('CONSUL_HOST', 'localhost')
+CONSUL_PORT = int(os.environ.get('CONSUL_PORT', 8500))
+CONSUL_COUNTER_KEY = 'service/ids/counter'
+MAX_RETRIES = 5  # Max attempts for atomic update
+RETRY_DELAY_SECONDS = 0.1  # Delay between retries for atomic update
+
+logger = logging.getLogger(__name__)
+
+
+def generate_fallback_id() -> int:
+    """
+    Generate a fallback ID when Consul is not available.
+    Uses a combination of timestamp, hostname hash, and random number.
+    
+    Returns:
+        int: A reasonably unique integer ID
+    """
+    # Get current timestamp in milliseconds
+    timestamp = int(time.time() * 1000)
+    
+    # Get hostname and hash it to an integer
+    hostname = socket.gethostname()
+    hostname_hash = hash(hostname) % 10000  # Limit to 4 digits
+    
+    # Generate a random number
+    random_part = random.randint(0, 9999)  # 4 digits
+    
+    # Combine all parts into a single integer
+    # Format: TTTTTTTTTTT-HHHH-RRRR (T=timestamp, H=hostname hash, R=random)
+    unique_id = (timestamp * 100000000) + (hostname_hash * 10000) + random_part
+    
+    logger.warning(f"Using fallback ID generation method: {unique_id}")
+    return unique_id
+
+
+def get_unique_instance_id() -> int:
+    """
+    Get a globally unique ID from Consul.
+    Uses Consul's atomic Compare-And-Set operations to safely increment a counter.
+    Falls back to a local generation method if Consul is unavailable.
+    
+    Returns:
+        int: A globally unique integer ID
+    """
+    try:
+        # Connect to Consul
+        c = consul.Consul(host=CONSUL_HOST, port=CONSUL_PORT)
+        
+        # Try to get the current counter value
+        index, data = c.kv.get(CONSUL_COUNTER_KEY)
+        
+        # If the key doesn't exist yet, create it with initial value
+        if data is None:
+            logger.info(f"Initializing Consul counter at {CONSUL_COUNTER_KEY}")
+            if c.kv.put(CONSUL_COUNTER_KEY, "1"):
+                return 1
+            else:
+                logger.error("Failed to initialize Consul counter")
+                return generate_fallback_id()
+        
+        # Get the current value
+        current_value = int(data['Value'].decode('utf-8'))
+        new_value = current_value + 1
+        
+        # Try to atomically update the counter
+        for attempt in range(MAX_RETRIES):
+            # Use Compare-And-Set to ensure atomicity
+            success = c.kv.put(
+                CONSUL_COUNTER_KEY, 
+                str(new_value), 
+                cas=data['ModifyIndex']
+            )
+            
+            if success:
+                logger.debug(f"Successfully obtained unique ID: {new_value}")
+                return new_value
+            
+            # If CAS failed, someone else updated the value, retry
+            logger.debug(f"CAS update failed on attempt {attempt+1}, retrying...")
+            time.sleep(RETRY_DELAY_SECONDS)
+            
+            # Get the latest value for the next attempt
+            index, data = c.kv.get(CONSUL_COUNTER_KEY)
+            if data is None:
+                logger.error("Counter disappeared during update")
+                return generate_fallback_id()
+                
+            current_value = int(data['Value'].decode('utf-8'))
+            new_value = current_value + 1
+        
+        # If we've exhausted all retries, use the fallback
+        logger.error(f"Failed to update counter after {MAX_RETRIES} attempts")
+        return generate_fallback_id()
+        
+    except Exception as e:
+        logger.error(f"Error accessing Consul: {str(e)}")
+        return generate_fallback_id()