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Glossary

  • Agile: An umbrella term for a collection of frameworks and techniques that together enable teams and individuals to work in a way that is typified by collaboration, prioritization, iterative and incremental delivery, and time-boxing. These are several specific methods (or frameworks) that are classed as Agile, such as Scrum, Lean, and Kanban.

  • APIRouter: A FastAPI class used to organize and decouple endpoint routing. It allows developers to split large applications into multiple modular files, preventing monolithic architecture. See [[textbooks/fastapi/index]] for usage.

  • ARP Cache: The local table used by an operating system to map IP addresses to physical MAC addresses. Following Keepalived or Kube-VIP failovers, stale entries in this cache on client machines can lead to connection timeouts (e.g. connect: no route to host). See [[how-to/post-power-outage-recovery]].

  • acme-companion: A companion Docker container for nginx-proxy that automates the creation, renewal, and installation of Let's Encrypt SSL certificates by monitoring Docker events and verifying domains via HTTP-01 challenges. See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • Build-time Serialization: The build-time process of scanning, parsing, and converting dynamic file-based resources (such as Markdown files) into a static, optimized payload (like JSON). This technique decouples the physical content repository from the production backend environment, maximizing security and eliminating runtime parsing overhead. See [[how-to/build-zettelkasten-graph-fastapi]] for practical details.

  • Breakpoint (Responsive): A specific screen width threshold defined in CSS media queries (e.g., @media (max-width: 1023.98px)) that triggers layout and styling changes to adapt the user interface to different devices. See [[textbooks/fastapi/index]].

  • change: The addition, modification, or removal of anything that could have a direct or indirect effect on services.

  • change authority: The person or group who authorizes a change.

  • CI: (Configuration Item) Any component that needs to be managed in order to deliver an IT service.

  • cordon: (Kubernetes) Marking a node as unschedulable so that the Kubernetes scheduler will not place any new pods on it. Existing pods continue running. Used before maintenance operations. See also: drain, uncordon.

  • CIR: (Continual Improvement Register) A structured database or document that is used to track and manage improvement opportunities.

  • Circular Import Mitigation: The software engineering practice of resolving cyclic dependencies between modules (e.g., Module A importing Module B while Module B imports Module A). Common techniques include moving shared instantiation logic to a third, independent module or utilizing local imports inside functions. See [[textbooks/fastapi/index]] for a theoretical breakdown.

  • Cache-Buster: A mechanism used to force browser clients to bypass their local cache and fetch the latest version of a static asset (such as CSS or JS). This is achieved by appending a unique query parameter signature (e.g., ?v=1.0.1) to the asset URL, altering its cache key. See [[learning/fastapi/static-files]].

  • Cache Layer (Docker): An intermediate read-only image layer generated during the execution of an instruction in a Dockerfile. Subsequent builds reuse these cached layers to accelerate build times, unless forced to compile cleanly using the --no-cache flag. See [[how-to/deploy-docker-compose-updates]].

  • Container Recreation: The process of destroying a running Docker container and launching a fresh instance built from an updated image. Simply rebuilding an image does not automatically apply modifications to a running container; recreation is required (e.g. via docker compose up -d). See [[how-to/deploy-docker-compose-updates]].

  • Colima: A lightweight, command-line container runtime for macOS (and Linux) that serves as an open-source alternative to Docker Desktop. It provisions a minimal Linux VM to run the Docker daemon. See [[how-to/setup-local-dev-docker-colima]].

  • continual improvement practice: The practice of aligning an organization's practices and services with changing business needs through the ongoing identification and improvement of all elements involved in the effective management of products and services.

  • cost: The amount of money spent on a specific activity or resource. Cost can also be expressed in non-monetary terms.

  • CRI: (Container Runtime Interface) The plugin interface which enables kubelet to use a wide variety of container runtimes, without the need to recompile Kubernetes.

  • CSF: (critical success factor) A necessary precondition for the achievement of intended results.

  • customer: The role that defines the requirements for a service and takes responsibility for the outcomes of service consumption.

  • CX: (customer experience) The sum of functional and emotional interactions with a service and service provider as perceived by a customer.

  • D3.js Force Simulation: A physics engine provided by the D3.js library that models physical forces (like charge, gravity, and link distance) between nodes and connections. It dynamically calculates coordinate positions in the client's browser to render interactive force-directed graph visualizations. See [[how-to/build-zettelkasten-graph-fastapi]] for practical details.

  • Database Portability: The architectural practice of designing database connections to adapt dynamically to the environment (e.g. falling back to a local zero-dependency SQLite file for local testing and connecting to a PostgreSQL container when running under Docker). See [[textbooks/fastapi/index]].

  • Decorator: A Python syntax construct that modifies the behavior of a function, method, or class. In web frameworks like FastAPI, decorators are used to bind URL routes to handler functions. See [[textbooks/fastapi/index]].

  • demand: Input to the Service Value System based on opportunities and needs from internal and external stakeholders.

  • Dependency Deadlock: A scenario where service components fail to boot successfully because they depend on other services that are either offline or scheduled to start after them (such as Kubernetes pods crashlooping because the dynamic NFS storage provider cannot reach the offline NAS array). See [[how-to/post-power-outage-recovery]].

  • DevOps: An organizational culture that aims to improve the flow of value to customers. DevOps focuses on culture, automation, Lean, measurement, and sharing (CALMS).

  • .dockerignore: A configuration file used in Docker builds to specify files and folders (such as local .venv or temporary database directories) that should be excluded from the build context, preventing host environment pollution from corrupting the container filesystem. See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • DKMS: (Dynamic Kernel Module Support) A framework that enables generating Linux kernel modules whose sources reside outside the kernel source tree. Commonly used for proprietary drivers like NVIDIA.

  • drain: (Kubernetes) The process of safely evicting all pods from a node and marking it as unschedulable (cordoned). Used to prepare a node for maintenance, upgrades, or shutdown. See also: cordon, uncordon.

  • event: Any change of state that has significance for the management of a service or other configuration item (CI).

  • FastAPI: A modern, high-performance web framework for building APIs with Python 3.8+ based on standard Python type hints. Features automatic OpenAPI documentation, automatic validation, and serialization. See [[textbooks/fastapi/index]].

  • feedback loop: A technique whereby the outputs of one part of a system are used as inputs to the same part of the system.

  • File-Watching VM Barrier: The boundary in virtualized development environments (like Docker containers running inside a macOS hypervisor VM) where host filesystem modification events fail to propagate to the guest OS. This requires configuring watchers to actively poll directories. See [[textbooks/containerization/index]].

  • four dimensions of service management: The four perspectives that are critical to the effective and efficient facilitation of value for customers and other stakeholders in the form of products and services.

  • Function: A reusable block of code designed to perform a specific task, taking input arguments and returning outputs.

  • governance: The means by which an organization is directed and controlled.

  • holistic: The treatment of the system as a whole and not just the sum of its parts.

  • HBA: (Host Bus Adapter) A circuit board and/or integrated circuit adapter that provides I/O processing and physical connectivity between a host system and storage devices. Often flashed to "IT Mode" for software RAID (ZFS).

  • incident: An unplanned interruption to a service, or reduction in the quality of a service.

  • information and technology: One of the four dimensions of service management. It includes the information and knowledge used to deliver services, and the information and technologies used to manage all aspects of the Service Value System.

  • IT asset: Any financially valuable component that can contribute to delivery of an IT product or service.

  • ITIL: Best-practice guidance for IT service management.

  • ITIL guiding principles: Recommendations that can guide an organization in all circumstances, regardless of changes in its goals, strategies, types of work, or management structure.

  • ITIL service value chain: An operating model for service providers that covers all the key activities required to effectively manage products and services.

  • JBOD: (Just a Bunch Of Disks) A storage architecture using multiple hard drives exposed directly to the operating system as individual disks, allowing software like ZFS to manage them instead of a hardware RAID controller.

  • Kanban: A method for visualizing work, identifying potential blockages and resource conflicts, and managing work in progress.

  • known error: A problem that has been analyzed but has not been resolved.

  • lazydocker: A terminal-based user interface (TUI) dashboard for managing Docker containers, images, volumes, and networks. See [[how-to/setup-local-dev-docker-colima]].

  • KPI: (key performance indicator) An important metric used to evaluate the success in meeting an objective.

  • Kube-VIP: A lightweight Kubernetes load-balancing tool that provides a highly available virtual IP (VIP) address for control plane nodes, managing VIP bindings dynamically to prevent API server access loss. See [[how-to/post-power-outage-recovery]].

  • Lean: An approach that focuses on improving workflows by maximizing value through the elimination of waste.

  • metric: A measurement or calculation that is monitored or reported for management and improvement.

  • MIME Sniffing: A mechanism by which web browsers examine the content of a byte stream to deduce the file type, rather than relying strictly on the server-provided Content-Type header. To mitigate security vulnerabilities, this behavior can be blocked using the X-Content-Type-Options: nosniff header, which forces the browser to obey the server's declared MIME type.

  • Mixed Content: A security mechanism where web browsers loading a page over a secure connection (https://) block active resources (such as CSS stylesheets or script files) requested over an insecure connection (http://) to prevent interception and manipulation. See [[reference/web-development/fastapi-static-files]].

  • mission: The overall purpose and intentions of an organization.

  • MVP: (Minimum Viable Product) A product with just enough features to satisfy early customers, and to provide feedback for future product development.

  • node: (Kubernetes) A machine (physical or virtual) that is part of a Kubernetes cluster. Control-plane nodes manage the cluster; worker nodes run application workloads.

  • NFS: (Network File System) A distributed file system protocol allowing a client computer to access files over a network much like local storage. Used in Kubernetes for ReadWriteMany persistent volumes.

  • Negative Margin (CSS): A styling technique where negative values are applied to an element's margin (e.g., margin-left: -2.5rem), pulling the element outward beyond its parent container's standard padding bounds. Commonly used to create full-bleed elements or expand nested structures on mobile screens. See [[textbooks/fastapi/index]].

  • Nginx Reverse Proxy: A server that sits in front of backend applications and forwards client requests to those applications based on rules like domain names. Commonly used to host multiple Docker containers on the same server sharing ports 80 and 443. See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • only-system (Python Preference): A configuration setting in the uv package manager (UV_PYTHON_PREFERENCE=only-system) that forces it to resolve dependencies against the host or container's system-installed Python interpreter, preventing it from downloading standalone python runtimes that would create broken virtualenv symlinks in multi-stage builds. See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • opportunity: Options or possibilities to add value for stakeholders or otherwise improve the organization.

  • organization: A person or a group of people that has its own functions with responsibilities, authorities, and relationships to achieve its objectives.

  • organizations and people: One of the four dimensions of service management. It ensures that the way an organization is structured and managed, as well as its roles, responsibilities, and systems of authority and communication, is well defined and supports its overall strategy and operating model.

  • outcome: A result for a stakeholder enabled by one or more outputs.

  • output: A tangible or intangible deliverable of an activity.

  • partners and suppliers: One of the four dimensions of service management. It encompasses the relationships an organization has with other organizations that are involved in the design, development, deployment, delivery, support, and/or continual improvement of services.

  • partnership: A relationship between two organizations that involves working closely together to achieve common goals and objectives.

  • performance: A measure of what is achieved or delivered by a system, person, team, practice, or service.

  • pod: (Kubernetes) The smallest deployable unit in Kubernetes. A pod wraps one or more containers and provides them with a shared network namespace and storage volumes.

  • practice: Sets of organizational resources designed for performing work or accomplishing an objective.

  • problem: A cause, or potential cause, of one or more incidents.

  • process: A set of interrelated or interacting activities that transform inputs into outputs. Processes define the sequence of actions and their dependencies.

  • product: A configuration of an organization's resources designed to offer value for a consumer.

  • Proxy Headers: HTTP request headers (such as X-Forwarded-Proto, X-Forwarded-For, and X-Forwarded-Port) injected by reverse proxies to convey the original client connection properties to the backend application server. See [[reference/web-development/fastapi-static-files]].

  • psycopg: A modern PostgreSQL database adapter library for Python, conforming to the PEP 249 DB-API standard. See [[textbooks/fastapi/index]].

  • release: A version of a service or other configuration item, or a collection of configuration items, that is made available for use.

  • Request Body: JSON (or other format) data transmitted within the body of an HTTP request (such as POST or PUT) to an API. In FastAPI, request bodies are typically defined and validated using Pydantic models. See [[textbooks/fastapi/index]].

  • resource: Personnel, material, finance or other entity required for the execution of an activity or the achievement of an objective. Resources used by an organization may be owned by the organization or used according to an agreement with the resource owner.

  • Response: The payload or data returned by an API endpoint to the client after processing a request (e.g. JSON, HTML, plain text, or binary files). See [[textbooks/fastapi/index]].

  • Restore on AC Power Loss: A motherboard UEFI/BIOS power management setting that determines whether a physical server automatically boots back up when utility power is restored after a blackout. See [[how-to/post-power-outage-recovery]].

  • risk: A possible event that could cause harm or loss, or make it more difficult to achieve objectives. Risk can also be defined as uncertainty of outcome, and can be used in the context of measuring the probability of positive outcomes as well as negative outcomes.

  • Route: A URL path mapped to a specific handler function in a web application or API. In FastAPI, routes are declared using decorator syntax on the application or router instance. See [[textbooks/fastapi/index]].

  • Secure Boot: A UEFI feature that prevents malicious software and unauthorized operating systems from loading during the boot process. It strictly blocks unsigned kernel modules (like DKMS proprietary drivers).

  • service: A means of enabling value co-creation by facilitating outcomes that customers want to achieve, without the customer having to manage specific costs and risks.

  • service catalog: Structured information about all the services and service offerings for a service provider, relevant for a specific target audience.

  • service consumption: Activities performed by an organization to consume services. It includes the management of the consumer's resources needed to use the service, service actions performed by users, and the receiving (acquiring) of goods (if required).

  • service desk: The point of communication between the service provider and all of its users.

  • service management: A set of specialized organizational capabilities for enabling value for customers in the form of services.

  • service offering: A formal description of one or more services, designed to address the needs of a target consumer group. A service offering may include goods, access to resources, and service actions.

  • service provider: A role performed by an organization in a service relationship to provide services to consumers.

  • service provision: Activities performed by an organization to provide services. It includes management of the provider's resources; configured to deliver the service, ensuring access to these resources for users; fulfillment of the agreed service actions; service level management; and continual improvement. It may also include the supply of goods.

  • service relationship: A cooperation between a service provider and service consumer. Service relationships include service provision, service consumption, and service relationship management.

  • service relationship management: Joint activities performed by a service provider and a service consumer to ensure continual value co-creation based on agreed and available service offerings.

  • service request: A request from a user or user's authorized representative that initiates a service action which has been agreed as a normal part of service delivery.

  • Shared Docker Network: An external Docker network that acts as a bridge, allowing completely independent Docker Compose projects to communicate securely with each other (such as a reverse proxy routing to separate backend stacks). See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • SLA: (Service Level Agreement) A documented agreement between a service provider and a customer that identifies both services required and the expected level of service.

  • sponsor: The role that authorizes budget for service consumption. Can also be used to describe an organization or individual that provides financial or other support for an initiative.

  • SSL Termination: The process of decrypting SSL/TLS encrypted traffic at a proxy, load balancer, or web server before passing the unencrypted HTTP traffic to the backend application server, relieving backend containers of cryptographic overhead. See [[how-to/host-multiple-docker-projects-with-shared-nginx-proxy]].

  • Strict MIME-Type Checking: A security enforcement mechanism where web browsers refuse to load, execute, or apply external assets (such as CSS stylesheets or JavaScript files) unless the server transmits them with the precise, correct Content-Type header (e.g. text/css for style sheets). This security boundary prevents cross-site script execution and style injection. See [[learning/fastapi/static-files]] and [[how-to/configure-fastapi-static-mime]] for diagnostic steps.

  • supplier: A stakeholder responsible for providing services that are used by an organization.

  • SVS: (Service Value System) A model representing how all the components and activities of an organization work together to facilitate value creation.

  • systems thinking: A holistic approach to analysis that focuses on the way that a system's constituent parts work, interrelate, and interact over time, and within the context of other systems.

  • TOC: (Theory of Constraints) A method of continual improvement that involves identifying the weakest link in the value chain (i.e. the constraint) and then making systematic improvements until it is no longer the weakest link.

  • uncordon: (Kubernetes) Marking a previously cordoned node as schedulable again, allowing the Kubernetes scheduler to place new pods on it. Typically performed after maintenance is complete and the node has rejoined the cluster. See also: cordon, drain.

  • user: The role that uses services.

  • utility: The functionality offered by a product or service to meet a particular need. Utility can be summarized as "what the service does" and can be used to determine whether a service is "fit for purpose." To have utility, a service must either support the performance of the consumer or remove constraints from the consumer. Many services do both.

  • vanilla CSS: Plain CSS code written directly in standard stylesheet files without using utility-first compilation frameworks (like Tailwind CSS) or processors (like Sass).

  • UX: (user experience) The sum of functional and emotional interactions with a service and service provider as perceived by a user.

  • value: The perceived benefits, usefulness, and importance of something.

  • value stream: A step in the value chain that an organization takes in the creation of value.

  • value stream and processes: One of the four dimensions of service management. It defines the activities, workflows, controls, and procedures needed to achieve the agreed objectives.

  • vision: A defined aspiration of what an organization would like to become in the future.

  • warranty: Assurance that a product or service will meet agreed requirements. Warranty can be summarized as "how the service performs" and can be used to determine whether a service is "fit for use." Warranty often relates to service levels aligned with the needs of service consumers. This may be based on a formal agreement, or it may be a marketing message or brand image. Warranty typically addresses such areas as the availability of the service, its capacity, levels of security, and continuity. A service may be said to provide acceptable assurance, or "warranty," if all defined and agreed conditions are met.

  • Wikilinks: A shorthand hypertext syntax (typically formatted as [[Page Name]]) popularized by wikis and personal knowledge management tools (such as Obsidian). It allows direct cross-referencing between related articles or notes without specifying raw filesystem paths. See [[how-to/build-zettelkasten-graph-fastapi]] for practical details.

  • workaround: A solution that reduces or eliminates the impact of an incident or problem for which a full resolution is not yet available. Some workarounds reduce the likelihood of incidents.