Kamailio Shared Memory to Prometheus Exporter

kamailio_shm_to_prom.py

# Script to dump Kamailio shared memory stats to Prometheus
# Nick Jones - 2025
#Writeup about what this does and why it's here is at:
# https://nickvsnetworking.com/profiling-kamailio-module-memory-usage/

import time
import subprocess
import re
from prometheus_client import start_http_server, Gauge

# Create Prometheus Gauge metrics
KAMAILIO_SHM_STATS = Gauge(
    "kamailio_shm_stats",
    "Kamailio shared memory statistics",
    ["module", "key"]
)

KAMAILIO_SHM_TOTALS = Gauge(
    "kamailio_shm_totals",
    "Kamailio shared memory totals per module",
    ["module"]
)

def execute_kamcmd():
    """
    Execute the 'kamcmd mod.stats all shm' command and return its output.
    """
    try:
        result = subprocess.run(
            ["kamcmd", "mod.stats", "all", "shm"],
            capture_output=True,
            text=True,
            check=True
        )
        return result.stdout
    except subprocess.CalledProcessError as e:
        print(f"Error executing 'kamcmd mod.stats all shm': {e}")
        return None

def parse_kamcmd_output(output):
    """
    Parse the output of 'kamcmd mod.stats all shm' into a structured format.
    """
    data = {}
    totals = {}
    module = None
    for line in output.splitlines():
        line = line.strip()
        if line.startswith("Module:"):
            module = line.split(":")[1].strip()
            data[module] = {}
            totals[module] = 0  # Initialize total for the module
        elif line.startswith("Total:"):
            if module:
                # Extract the total value
                total_value = int(line.split(":")[1].strip())
                totals[module] = total_value
        elif line and module:
            # Match lines like "counters_prefork_init(211): 213248"
            match = re.match(r"(.+?)\(\d+\):\s+(\d+)", line)
            if match:
                key = match.group(1).strip()
                value = int(match.group(2))
                data[module][key] = value
    return data, totals

def update_metrics(data, totals):
    """
    Update Prometheus metrics with the parsed data and totals.
    """
    for module, metrics in data.items():
        # Update individual metrics
        for key, value in metrics.items():
            KAMAILIO_SHM_STATS.labels(module=module, key=key).set(value)
        # Update the total for the module
        KAMAILIO_SHM_TOTALS.labels(module=module).set(totals.get(module, 0))

def main():
    # Start the Prometheus HTTP server on port 9097
    start_http_server(9097)
    print("Prometheus metrics server started on port 9097")

    # Run in an infinite loop
    while True:
        # Execute the kamcmd command
        output = execute_kamcmd()
        if output:
            # Parse the output
            data, totals = parse_kamcmd_output(output)
            # Update Prometheus metrics
            update_metrics(data, totals)
            print("Metrics updated")
        else:
            print("Failed to fetch metrics")

        # Wait for 60 seconds before the next update
        time.sleep(60)

if __name__ == "__main__":
    main()