Resolving DNAT Rule Shadowing and Port Mismatch on Eltex Gateways

Summary A critical connectivity failure occurred during the implementation of a Destination Network Address Translation (DNAT) policy on an Eltex gateway. The intent was to expose internal services (HTTP and SSH) to a public network by mapping a public “UPLINK” address to private server IPs. However, the configuration logic contained overlapping rules and protocol mismatches, … Read more

How to fix dumpdata failures in Wagtail 7.3 by cleaning orphaned pages

Summary An upgrade from Wagtail 7.2.3 to 7.3.1 caused the manage.py dumpdata command to fail when attempting to export wagtailcore using the –natural-foreign and –natural-primary flags. The failure manifests as a DoesNotExist exception during the serialization process, specifically when the Django serializer attempts to resolve a relationship to a Page object that the database claims … Read more

Debugging a MediaWiki‑MariaDB Docker Compose stack that silently fails due to pl

Summary This postmortem covers a common Docker Compose misconfiguration when deploying MediaWiki against MariaDB. The supplied docker-compose.yml contains placeholder tokens (—) in place of real values for the container name, database password, and other critical fields. While the structure of the compose file is mostly sound, these missing values prevent the stack from starting correctly … Read more

Fixing PowerShell HTML Parsing Quirks Mode with Doctype

Summary A production automation script failed to correctly parse and manipulate HTML structures using the HTMLFile COM object in PowerShell. Specifically, the DOM parser treated the <footer> tag as an empty, self-closing element rather than a container. This caused subsequent attempts to modify child elements or read the outer HTML of the container to return … Read more

Preventing Postgres search_path Drift During Spring Boot Migrations

Summary During a production migration, an application failed to locate newly created tables, leading to UndefinedTableException errors in the Spring Boot service. The investigation revealed that the tables were being created in the public schema by default, while the application’s connection string and search path were configured to look for a specific tenant-specific schema. This … Read more

Avoid Dependency Conflicts with Virtual Environment Practices

Summary Poor environment management in Python projects leads to dependency conflicts, reproducibility issues, and team collaboration breakdowns. This postmortem examines the critical importance of proper virtual environment setup and dependency management for Python projects. Root Cause The fundamental issue stems from not isolating project dependencies through virtual environments. Without isolation: Global package installations create version … Read more

Fixing .NET Config Binder Issues with Enumerable Properties in a Production Outa

Summary A production outage was triggered when a critical configuration update failed to propagate to a service. The issue stemmed from a misunderstanding of how the Microsoft.Extensions.Configuration.Binder interacts with collection types and static properties. While the configuration existed in appsettings.json, the application continued to operate with empty default values, leading to unauthorized access attempts and … Read more