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How to Implement Region Failover Config in Python with Primary and Secondary Mock
This Python class simulates regional failover: it tracks active region, switches to secondary on primary failure, and allows manual recovery.
import time
class RegionFailoverConfig:
def __init__(self, primary, secondary):
self.primary = primary
self.secondary = secondary
self.active = primary
self.failover_count = 0
self.healthy = True
def check_health(self):
"""Mock health check - returns True if ac…How to Implement Retry with Exponential Backoff for Cloud API 429 Errors in Python
Implement a retry-with-backoff loop in Python to handle 429 throttling errors from cloud APIs, using exponential delay between attempts.
import time
import random
import requests
def api_call(attempt):
"""Mock cloud API that returns 429 for the first two attempts."""
if attempt < 2:
return 429, "Too Many Requests"
return 200, {"data": "success"}
def retry_with_backoff(api_func, max_retries=3, base_delay=0.1):
for attempt in …How to Mock AWS SQS Send Receive Delete in Python
Build an in-memory mock of the SQS send, receive, and delete message flow for local testing.
import json
from collections import deque
from uuid import uuid4
class MockSQSQueue:
def __init__(self, name):
self.name = name
self._messages = deque()
self._in_flight = {}
def send_message(self, body, attributes=None):
message_id = str(uuid4())
message = {
…How to Mock AWS Secrets Manager in Python
Create a lightweight mock of AWS Secrets Manager's get_secret_value API to test secret retrieval without cloud dependencies.
import json
from typing import Optional
class MockSecretsManager:
"""A simple mock of AWS Secrets Manager's get_secret_value API."""
def __init__(self):
self._secrets: dict[str, str] = {}
def create_secret(self, secret_id: str, secret_value: str) -> None:
"""Store a secret value under a…How to Mock Auto Scaling Policy Scale Out in Python
Define a mock auto-scaling function that scales out capacity by a factor up to a max, simulating AWS-like events.
def mock_scale_out(current_capacity: int, max_capacity: int, scale_factor: int = 1) -> tuple:
"""
Mock auto-scaling policy: scales out by the specified factor
if capacity allows, capped at max_capacity.
"""
if current_capacity >= max_capacity:
return current_capacity, False
new_cap…How to Mock Azure Key Vault Secret Get in Python
Mock an Azure Key Vault client's get_secret method with unittest.mock to test functions that retrieve secret values without hitting the real service.
import unittest
from unittest.mock import MagicMock, patch
def get_secret(key_vault_client, secret_name):
"""Retrieve a secret value from an Azure Key Vault client."""
secret = key_vault_client.get_secret(secret_name)
return secret.value
class TestKeyVaultSecretGet(unittest.TestCase):
def test_get_…How to Mock Azure Service Bus Queue in Python
A lightweight in-memory mock of the Azure Service Bus queue API for local testing without cloud dependencies.
import json
import time
from collections import deque
class ServiceBusQueueMock:
def __init__(self, queue_name):
self.queue_name = queue_name
self._messages = deque()
self._dead_letter_queue = deque()
self._message_counter = 0
def send_message(self, body, message_id=None, prop…How to Mock CloudFront Invalidation Paths in Python
Build a sorted, deduplicated list of CloudFront invalidation paths from a set of file paths, adding implicit index.html entries.
import argparse
def build_invalidation_paths(files, include_index=True):
"""
Create CloudFront invalidation paths from a list of files.
Converts file names to root-relative paths and optionally adds /index.html.
"""
paths = []
for f in files:
f = f.strip()
if not f:
…How to Mock DynamoDB with a Simple Dict Store in Python
A lightweight in-memory DynamoDB mock that stores items in a dict and supports put, get, and query-by-value operations for local testing.
import json
from typing import Any, Dict, Optional
class MockDynamoDB:
def __init__(self) -> None:
self._store: Dict[str, Dict[str, Any]] = {}
def put_item(self, table_name: str, item: Dict[str, Any]) -> None:
key = str(item.get("id"))
if table_name not in self._store:
se…How to Mock ELB Target Health Status in Python
Simulate AWS Elastic Load Balancer target health checks with a Python dict that mutates status and healthy host counts.
from random import randint
def elb_target_mock_status(target_id, healthy=True):
targets = {
1: {"Id": "i-001", "Status": "healthy", "Port": 80, "HealthyHostCount": 1},
2: {"Id": "i-002", "Status": "unhealthy", "Port": 80, "HealthyHostCount": 0},
3: {"Id": "i-003", "Status": "healthy", "Por…How to Mock GCP Cloud Functions HTTP Events in Python
Simulate a GCP Cloud Functions HTTP event with a Python mock handler that constructs a realistic event payload and returns a JSON response.
import json
from datetime import datetime, timezone
def mock_http_event(data):
"""Simulate a GCP Cloud Function HTTP event."""
event = {
"event_id": "mock-event-12345",
"timestamp": datetime.now(timezone.utc).isoformat(),
"event_type": "google.cloud.functions.http",
"resource"…How to Mock Pulumi Stack Outputs in Python
Create a dict-like mock of Pulumi stack outputs for local testing and scripts without running pulumi.
from collections import defaultdict
class StackOutputMock:
def __init__(self, outputs: dict):
self.outputs = dict(outputs)
def export(self):
return self.outputs
def get(self, key: str, default=None):
return self.outputs.get(key, default)
def keys(self):
r…How to Mock RDS Snapshot Create and Restore in Python
Mock AWS RDS snapshot creation and restore operations in Python tests using moto and boto3 without hitting real AWS services.
import boto3
from moto import mock_rds
@mock_rds
def create_and_restore_snapshot():
client = boto3.client("rds", region_name="us-east-1")
client.create_db_instance(
DBInstanceIdentifier="my-db",
DBInstanceClass="db.t3.micro",
Engine="postgres",
AllocatedStorage=20,
Mas…How to Paginate a List with a Generator in Python
Define a generator that yields list items in fixed-size pages, simulating pagination for cloud resource APIs.
from typing import List, Iterator
def paginate_generator(items: List[str], page_size: int = 3) -> Iterator[List[str]]:
"""Yield items in fixed-size chunks with a mock pagination pattern."""
for i in range(0, len(items), page_size):
yield items[i:i + page_size]
if __name__ == "__main__":
resources…How to Parse Cloud JSON Data in Python
A helper function that safely parses JSON payloads from cloud services into a clean dict with defaults and error handling.
import json
from typing import Dict, Any
def parse_cloud_data(payload: str) -> Dict[str, Any]:
"""Parse a JSON payload from a cloud service into a clean dict."""
try:
data = json.loads(payload)
return {
"status": data.get("status", "unknown"),
"region": data.get("region…How to Parse Terraform Output JSON in Python
Parse Terraform's JSON output into a flat dictionary of values using the standard library json module.
import json
def parse_terraform_output(raw_output):
"""Parse Terraform JSON output into a flat dict of values."""
try:
data = json.loads(raw_output)
except json.JSONDecodeError as e:
raise ValueError(f"Invalid JSON: {e}")
return {key: value["value"] for key, value in data.items()}
i…How to Parse an AWS API Gateway Proxy Event in Python
Extract and parse common fields from a mock API Gateway proxy event, turning the JSON body into a native Python dict.
import json
from typing import Any, Dict, Optional
def parse_proxy_event(event: Dict[str, Any]) -> Dict[str, Any]:
"""Extract and parse common fields from an API Gateway proxy event."""
body = event.get("body", "")
if isinstance(body, str):
body = json.loads(body) if body else {}
elif body is…How to Validate AWS Security Group Ingress Rules in Python
Validates AWS security group ingress rules (protocol, port ranges, CIDR, description) and returns a list of errors or OK.
from dataclasses import dataclass
from typing import List, Optional
@dataclass
class SecurityGroupRule:
protocol: str
port_range: tuple
cidr: str
description: str = ""
def validate_ingress_rule(rule: SecurityGroupRule) -> List[str]:
"""Validate a security group ingress rule against common AWS pat…How to Validate Data Fields and Types in Python
Validate required fields and type correctness in a Python dictionary with small helper functions, returning a list of clear error messages.
import json
from typing import Any, Dict, List
def validate_data(data: Dict[str, Any], required_fields: List[str]) -> List[str]:
"""Check required fields exist and are non-empty. Return list of errors."""
errors = []
for field in required_fields:
value = data.get(field)
if value is None o…How to mock EC2 describe-instances tag filtering in Python
Simulate AWS EC2 describe-instances with tag-based filtering using a mock dataset and conditional list comprehension.
import json
from datetime import datetime, timezone
def mock_describe_instances(tag_key: str, tag_value: str) -> list[dict]:
"""Simulate EC2 describe-instances with tag filtering."""
all_instances = [
{"InstanceId": "i-0abc123", "State": "running", "Tags": [{"Key": "Name", "Value": "web-server"}, {"K…How to mock boto3 S3 upload file wrapper in Python
Wrap an S3 put_object call in a testable function that returns metadata, and mock boto3 to verify the upload without touching AWS.
import boto3
import io
def upload_file_to_s3(file_obj, bucket, key, object_metadata=None):
"""Upload a file-like object to S3 and return a metadata dict."""
s3 = boto3.client("s3")
content = file_obj.read()
s3.put_object(
Bucket=bucket,
Key=key,
Body=content,
Metadata=…How to mock boto3 S3 upload in Python
Shows how to mock the boto3 S3 client with unit tests and wrap an upload function to return a dictionary with status details.
import boto3
from unittest.mock import Mock, patch
class S3Uploader:
def __init__(self, bucket_name):
self.bucket_name = bucket_name
self.s3 = boto3.client("s3", region_name="us-east-1")
def upload_file(self, local_path, s3_key):
self.s3.upload_file(local_path, self.bucket_name, s3_ke…How to plan reserved capacity from a CSV in Python
Read a CSV of workloads with csv.DictReader and compute a mock reserved capacity plan with headroom per service.
import csv
import io
def plan_reserved_capacity(workloads_csv: str) -> list[dict]:
"""Read a CSV of workloads and return a plan for reserved capacity per service."""
reader = csv.DictReader(io.StringIO(workloads_csv))
plan = []
for row in reader:
service = row["service"]
avg_load = fl…Mock Route53 change_resource_record_sets in Python
This code demonstrates how to mock AWS Route53 change_resource_record_sets API calls using the botocore Stubber, allowing you to test DNS update logic without touching real infrastructure.
import boto3
from botocore.exceptions import ClientError
def mock_change_resource_record_sets():
"""Demonstrates Route53 change_resource_record_sets with a mock client."""
# Create a mock Route53 client
route53 = boto3.client('route53', region_name='us-east-1',
aws_access_key_id…Browse by section
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