How to use Paramiko to collect server metrics

Paramiko allows collecting server metrics remotely. This tutorial shows how to gather system information. This is very useful for monitoring.

Establishing an SSH Connection

First, establish a secure SSH connection to the server. This is the foundation for remote commands. This requires valid credentials.

import paramiko

def connect_to_server(hostname, username, password):
    try:
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(hostname, username, password)
        return ssh
    except Exception as e:
        print(f"Connection error: {e}")
        return None

ssh = connect_to_server("your_hostname", "your_username", "your_password")

Executing Commands Remotely

Use exec_command() to run commands on the server. This retrieves the output of the commands. This is how we get metrics.

import paramiko

def execute_command(ssh, command):
    try:
        stdin, stdout, stderr = ssh.exec_command(command)
        output = stdout.read().decode().strip()
        return output
    except Exception as e:
        print(f"Command execution error: {e}")
        return None

if ssh:
    uptime = execute_command(ssh, "uptime")
    print(f"Server Uptime: {uptime}")

Collecting CPU Usage

Use commands like top or mpstat to get CPU usage. Parse the output to extract relevant metrics. This provides insights into system load.

import paramiko
import re

if ssh:
    cpu_info = execute_command(ssh, "mpstat 1 1 | tail -1") # Get last line of mpstat
    if cpu_info:
        cpu_idle = float(cpu_info.split()[-1])
        cpu_usage = 100 - cpu_idle
        print(f"CPU Usage: {cpu_usage:.2f}%")

Collecting Memory Usage

Use the free -h command to get memory information. Parse the output to extract memory usage. This helps monitor memory resources.

import paramiko

if ssh:
    mem_info = execute_command(ssh, "free -h | grep Mem")
    if mem_info:
        mem_parts = mem_info.split()
        total_mem = mem_parts[1]
        used_mem = mem_parts[2]
        print(f"Total Memory: {total_mem}, Used Memory: {used_mem}")

Collecting Disk Space

Use the df -h command to get disk space information. Parse the output to extract disk usage. This helps monitor available storage.

import paramiko

if ssh:
    disk_info = execute_command(ssh, "df -h | grep /dev/vda1") # Change /dev/vda1 to your disk
    if disk_info:
      disk_parts = disk_info.split()
      used_space = disk_parts[2]
      available_space = disk_parts[3]
      print(f"Used Space: {used_space}, Available Space: {available_space}")

if ssh:
    ssh.close()