Concepts in DevOps & Cloud, page 13
Self-Hosted Runners: Bring Your Own CI/CD Hardware
A self-hosted runner is your own machine executing CI/CD jobs, giving you full control over its environment and network. Use it for private network access or custom hardware. The footgun: you are now responsible for all security, updates, and maintenance.
Kubernetes DNS: How Pods Find Each Other
Kubernetes DNS gives services and pods stable, human-readable names so you don't have to track ephemeral IP addresses. It's how a frontend pod finds a backend service.
Securing Cloud Database Endpoints
Treat your database endpoint like a public API, even if it's "internal." A Zero Trust approach verifies every connection request, granting access based on identity and context, not network location. This prevents unauthorized data access, a top cloud threat.
Pipeline Templates: Reusable CI/CD Building Blocks
Think of pipeline templates as versioned, shareable functions for your CI/CD. Instead of copy-pasting YAML, you import a standardized block of logic for tasks like security scanning or deployment.
Beyond 'Root Cause': Proximate vs. Contributing Factors
A proximate cause is an incident's final trigger, while contributing factors are the conditions that made it possible. This helps post-mortems move beyond blame to find systemic risks.
Managed Database Backups: Your Cloud's Undo Button
Think of managed backups as your cloud provider's automated safety net for your database. It periodically saves snapshots, letting you restore to a point in time after a failure.
Dynamic Pipelines: Parent-Child vs. Multi-Project
Break up monolithic CI/CD pipelines into smaller, independent ones. Use parent-child pipelines for dynamic jobs in one project (like a monorepo), or multi-project pipelines to coordinate across repos. The footgun: the parent pipeline doesn't wait by default.
Swiss Cheese Model: Layered Defenses Against Failure
Think of system defenses as slices of Swiss cheese. An accident happens only when the holes—weaknesses in each layer—align. It's used in post-mortems to see how small failures combine into a major outage.
Kubernetes Ingress: The Cluster's Smart Receptionist
Ingress acts as a smart receptionist for your cluster, routing external HTTP/S traffic to internal services based on host or path. This lets you expose many apps with one load balancer.
Policy as Code in CI/CD with OPA
Treat pipeline rules as code using Open Policy Agent (OPA) to automate guardrails. Instead of scripts, write declarative policies to check test coverage or validate dependency licenses.
Hindsight Bias: The 'Knew-It-All-Along' Postmortem Trap
Hindsight bias makes past failures seem obvious. In postmortems, this leads to blaming engineers for not seeing what's now clear, instead of fixing the system. The footgun is judging past decisions with present knowledge, which hides real systemic flaws.
Ingress Controller: Your Cluster's Smart Reverse Proxy
An Ingress Controller is the traffic cop for your Kubernetes cluster, directing external HTTP/S requests to the correct internal services. It exposes multiple services under a single IP, handling host and path routing.
Database Multi-AZ: High Availability vs. Read Scaling
Multi-AZ deployment is like a hot spare database in another datacenter for automatic failover. It's for critical systems where downtime is costly. The footgun is assuming all standbys serve reads; only the 'cluster' type does, not the 'instance' type.
Kubernetes LoadBalancer: Your App's Public Entry Point
A Kubernetes LoadBalancer Service automatically provisions a cloud provider's load balancer to expose your app externally. It's the simplest way to get a public IP, but creating one per service is expensive and inflexible. Use an Ingress for more control.
Managed Key-Value Databases: Scaling Without Server Chores
A managed key-value database is like an outsourced dictionary. You give it a key, it returns a value, and the cloud provider handles all scaling and server management. It's used for session stores or user profiles where you need fast lookups by a known ID.
Terraform: Manage Infrastructure as Code
Terraform lets you define cloud infrastructure—servers, databases, networks—in a text file, like a blueprint. It reads this file and builds everything for you, making setups on AWS, GCP, or Azure repeatable.
Managed Document Databases: Your Data, Their Ops
A managed document database is like a fully-staffed warehouse for your data. You store JSON-like objects, and the provider handles security, maintenance, and scaling. It's the default for cloud apps, but the convenience isn't free—watch for surprise bills.
AWS CloudFormation: Your AWS Infrastructure as a Blueprint
AWS CloudFormation is your infrastructure's blueprint. Declare AWS resources in a YAML/JSON file, and AWS builds it. This is perfect for creating repeatable, version-controlled environments.
Declarative vs. Imperative Automation
Declarative automation defines the desired end state (“what”), not the steps to get there (“how”). It's used in tools like Kubernetes to manage complex infrastructure, letting the system figure out the details.
Managed In-Memory Data Store: Speed Without the Sysadmin
A managed in-memory store is a high-speed valet for your data, sitting between your app and database to serve requests at microsecond latency. Use it for database acceleration or session stores. The footgun is treating it as a permanent database.
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