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Python Code Samples

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37 matches
System design patterns easy

How to Build a Health Check System with Instance Up and Down Status in Python

Track instance health by marking them up or down and simulating health checks with a mock class in Python.

health-check monitoring system-design
Python
from datetime import datetime
import random

class HealthChecker:
    def __init__(self):
        self.status = {}
    
    def mark_up(self, instance_id):
        self.status[instance_id] = {
            "state": "up",
            "last_check": datetime.now().isoformat(),
            "healthy": True
        }
    
  …
14 0 Open
API design & gRPC easy

How to Implement a REST DELETE Mock Server Returning 204 in Python

A minimal HTTP server mock that responds to DELETE requests with 204, 404, or 403 statuses based on the resource ID.

http-server rest mock
Python
import json
from http.server import BaseHTTPRequestHandler, HTTPServer

class MockHandler(BaseHTTPRequestHandler):
    def do_DELETE(self):
        if self.path.startswith("/api/resource/"):
            resource_id = self.path.split("/")[-1]
            if resource_id == "42":
                # Successful delete: 204 …
12 0 Open
API design & gRPC easy

How to Poll an Operation Status Endpoint in Python

Mock a polling endpoint in Python that simulates checking an async operation's status until it completes or times out.

polling api async
Python
import time
import random


def poll_status(url: str, timeout: float = 5.0) -> dict:
    """Mock a polling endpoint that eventually returns a completed status."""
    start = time.time()
    while time.time() - start < timeout:
        # Simulate delayed response
        time.sleep(0.2)
        # 80% chance to report …
13 0 Open
API design & gRPC easy

How to mock a REST POST endpoint in Python

Create a simple mock REST server that responds to POST requests with a 201 status and a JSON body.

http mock api
Python
import json
from http.server import BaseHTTPRequestHandler, HTTPServer


class MockHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        content_length = int(self.headers.get("Content-Length", 0))
        body = self.rfile.read(content_length) if content_length else b"{}"
        try:
            data = json…
12 0 Open
API design & gRPC easy

Return Proper HTTP Status Codes Table in Python

Mock HTTP status code table with proper numeric and textual representations, including formatted status lines and a filtered table view.

http-status api mock
Python
# Mock HTTP status code table with proper numeric and textual representations

codes = {
    200: "OK",
    201: "Created",
    204: "No Content",
    301: "Moved Permanently",
    302: "Found",
    304: "Not Modified",
    400: "Bad Request",
    401: "Unauthorized",
    403: "Forbidden",
    404: "Not Found",
    50…
13 0 Open
Observability & SRE easy

How to Check Service Readiness Dependencies in Python

This code simulates a readiness check for external dependencies (database, cache, queue) with mock availability data and reports readiness status.

readiness dependencies health-check
Python
import sys
from datetime import datetime


def check_dependencies(config):
    results = []
    for dep, required in config.items():
        available = mock_availability(dep)
        status = "READY" if available >= required else "NOT READY"
        results.append((dep, available, required, status))
    return result…
11 0 Open
Observability & SRE easy

How to Create a Deep Health Check Database in Python

Setup a SQLite-backed health check database, insert mock data with response times and statuses, and generate a report ordered by most recent check.

sqlite health-check database
Python
import sqlite3
from datetime import datetime, timedelta
from pathlib import Path

DB_PATH = Path("deep_health_check.db")


def setup_database():
    conn = sqlite3.connect(DB_PATH)
    cursor = conn.cursor()
    cursor.execute("""
        CREATE TABLE IF NOT EXISTS health_checks (
            id INTEGER PRIMARY KEY AU…
14 0 Open
Observability & SRE easy

How to Ship Logs to an Aggregator Endpoint in Python

Ship batched log entries to a mock HTTP aggregator endpoint with proper error handling and response status.

logging requests json
Python
import json
import requests
from datetime import datetime, timezone

LOG_ENTRIES = [
    {"timestamp": "2024-01-15T10:00:00Z", "level": "INFO", "message": "Server started"},
    {"timestamp": "2024-01-15T10:00:05Z", "level": "WARN", "message": "High memory usage"},
    {"timestamp": "2024-01-15T10:00:10Z", "level": "E…
13 0 Open
Database scaling & optimization easy

How to Mock Replica Lag Monitoring in Python

Simulates database replica lag with a mock monitor class that generates realistic lag metrics and health statuses.

replica-lag monitoring simulation
Python
import time
import random
from datetime import datetime, timedelta

class MockReplicaLagMonitor:
    def __init__(self, replicas=3, base_lag=0.5, jitter=0.2):
        self.replicas = [f"replica-{i}" for i in range(replicas)]
        self.base_lag = base_lag
        self.jitter = jitter
        self.last_write = dateti…
12 0 Open
Production deployment patterns easy

How to Build a Synthetic Monitor Mock in Python

Simulates a synthetic monitoring system in Python that collects latency samples, averages them, and reports service status as UP or DEGRADED.

monitoring dataclass simulation
Python
import random
import time
from dataclasses import dataclass, field
from statistics import mean


@dataclass
class SyntheticMonitor:
    service: str
    endpoint: str
    latency_ms: list[float] = field(default_factory=list)

    def check(self) -> float:
        latency = random.uniform(50.0, 250.0)
        self.late…
13 0 Open
Production deployment patterns easy

How to Create a Liveness Probe HTTP Mock in Python

Build a lightweight HTTP server in Python that mimics a Kubernetes-style liveness endpoint, returning JSON health status for local testing.

http healthcheck mock-server
Python
import http.server
import threading
import time


class LivenessHandler(http.server.BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/healthz":
            self.send_response(200)
            self.send_header("Content-Type", "application/json")
            self.end_headers()
            self.wfi…
15 0 Open
Production deployment patterns easy

How to Mock Docker Image Non-Root User in Python

This Python class simulates Docker image layers and inspects whether the final user is a non-root user, returning UID, GID, and security status.

docker security mock
Python
from pathlib import Path


class DockerImageMock:
    def __init__(self, name, tag):
        self.name = name
        self.tag = tag
        self.layers = []
        self.user = "root"

    def add_file(self, path, content):
        self.layers.append({"file": path, "content": content})

    def set_user(self, usernam…
11 0 Open
Production deployment patterns easy

How to build a maintenance mode page in Python

Mock a service maintenance status page that computes remaining downtime and lists affected features from a simple class.

maintenance status datetime
Python
from datetime import datetime

class MaintenanceMode:
    """Mock a maintenance mode status page for a service."""
    
    def __init__(self, service_name: str, scheduled_end: str):
        self.service_name = service_name
        self.scheduled_end = datetime.fromisoformat(scheduled_end)
        self.affected_featur…
13 0 Open

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