azure-defaults

name: azure-defaults description: 'UTILITY SKILL — Azure infrastructure defaults: regions, tags, naming (CAF), AVM-first policy, security baseline, unique suffix patterns. WHEN: "Azure naming convention", "CAF naming", "resource tags", "AVM module", "security baseline", "region default". USE FOR: any agent generating or planning Azure resources. DO NOT USE FOR: artifact template structures (use azure-artifacts), pricing lookups (read references/pricing-guidance.md on demand).' compatibility: Works with Claude Code, GitHub Copilot, VS Code, and any Agent Skills compatible tool. license: MIT metadata: author: jonathan-vella version: "2.0" category: azure-infrastructure

Azure Defaults Skill

IaC-flavoured mirror of the canonical Azure defaults declared in .github/copilot-instructions.md. Deep-dive content lives in references/ — load on demand.

Canonical source rule: if the tables below disagree with copilot-instructions.md, the canonical declaration wins. This skill restates them for IaC-output convenience only.

Quick Reference (Load First)

Default Regions

Required Tags (Azure Policy Enforced)

These 9 lowercase tags are the APEX baseline — they mirror the org-wide resource-group tag-deny policy (every key must exist on the RG or the deployment is denied). Use lowercase keys (mixing owner + Owner triggers AmbiguousPolicyEvaluationPaths). Always defer to 04-governance-constraints.md for the project's actual required list — discovered policy always wins.

Unique Suffix Pattern

Generate ONCE, pass to ALL modules:

var uniqueSuffix = uniqueString(resourceGroup().id)

Security Baseline (5-Line Summary)

For AVM pitfalls and deprecation patterns, read references/security-baseline-full.md.

Cost Monitoring Baseline

Non-negotiable for prod. Governance (04-governance-constraints.json cost_monitoring.*) always wins. Budget thresholds: 5 notifications (actual 80/100/125 + forecast 100/125). Required: budget + Action Group (AVM, create-or-reuse via preflight) + subscription-scoped anomaly alert. Opt-out via cost_monitoring_mode ∈ {enforced, minimal, deferred} (minimal/deferred non-prod only).

For the full contract, AVM lookup, governance precedence, and exception schema, read references/cost-alerts-baseline.md. For stack-specific snippets, read references/cost-alerts-bicep.md or references/cost-alerts-terraform.md.

VNet Planning Baseline

Interactive. Architect Phase 6b (between 6a SKU confirmation and Step 7 pricing) runs the gate whenever either trigger holds: (a) any services[].requires[] row contains vnet-integration or private-endpoints, OR (b) any services[].service_name is in the vnet-attached whitelist (App Gateway, AKS, VM/VMSS, APIM internal, Bastion, Azure Firewall, VPN/ER Gateway, NAT Gateway, App Gateway for Containers). Default address space 10.0.0.0/16 (greenfield; at least /22). Recommendation style: a single subnet table followed by per-row Apply edit / Skip / Done askMe loop. Opt-out via vnet_planning_mode ∈ {guided, fast, deferred} (deferred blocked for prod). Governance network_constraints always wins.

For the full contract — trigger contract, askQuestions templates, subnet sizing matrix per workload with Microsoft Learn citations, CIDR math, existing-VNet validation, AVM modules — read references/vnet-planning.md.

Deprecated Services (Do NOT Recommend for Greenfield)

Never recommend deprecated services (Azure AD B2C, Redis Enterprise E50, CDN WAF classic, App Gateway v1, CDN Standard Microsoft) for greenfield. Full retirement table + replacement guidance: references/deprecated-services.md.

Engine / Runtime Version Currency

For any managed service with a selectable engine or runtime version (MySQL / PostgreSQL, Redis, AKS Kubernetes version, Cosmos API, App Service runtime), pin the latest GA LTS version and confirm it against the service's version-support policy at plan time. Two failure modes to avoid:

• Retiring versions carried over from an older template (e.g. MySQL 8.0, whose standard support ends 2026-04-30). The version literal is a creative decision — resolve it live, don't copy it from a prior project.
• Innovation / preview releases (e.g. MySQL 9.x) for durable data workloads. Innovation releases exclude HA, replicas, and automated backups and have a short server lifecycle.

Example: MySQL Flexible Server → version: '8.4' (GA LTS → 8.4.x), not the retiring 8.0 or the innovation 9.x. A major-version change on an existing server is a separate concern — see iac-common/known-deploy-issues.md.

CAF Naming Conventions

For extended abbreviations and length-constraint examples, read references/naming-full-examples.md.

Azure Verified Modules (AVM)

1. ALWAYS check AVM availability first
2. ALWAYS pin to the latest published stable version — resolve live at plan time; never reuse a pin from a prior project or training data
3. Use AVM defaults for SKUs when available
4. NEVER write raw Bicep/TF for a resource that has an AVM module

For module paths, the live-lookup procedure (MCR for Bicep, registry.terraform.io for Terraform, MCP equivalents), the validator (npm run validate:avm-versions:freeze — MUST run before apex-recall complete-step 4), and the structured pin_policy schema for stale-pin exceptions, read references/avm-modules.md.

Rules

All baseline rules (region, tags, security, cost monitoring, deprecated services) are stated in Quick Reference above — that is the canonical form. The invariants below are gate-level / non-negotiable:

• AVM-first — never write raw Bicep/TF for a resource that has an AVM module
• Pin AVM live at plan time — stale pins require pin_policy.mode = "exception" in 04-iac-contract.json; enforced by npm run validate:avm-versions:freeze
• Tag casing is case-sensitive — never emit both owner and Owner (AmbiguousPolicyEvaluationPaths error)
• Unique suffix — generate uniqueString(resourceGroup().id) ONCE per deployment
• Governance wins — 04-governance-constraints.md overrides any default in this skill (tags, regions, SKUs, cost monitoring)
• VNet planning is interactive — never auto-pick CIDRs without confirmation. Trigger: any services[].requires[] ∈ {vnet-integration, private-endpoints} OR services[].service_name in vnet-attached whitelist. Governance network_constraints overrides defaults. Contract: references/vnet-planning.md.

Steps

1. Read Quick Reference — region, tags, suffix, security baseline
2. Cross-check governance — 04-governance-constraints.md overrides defaults
3. Pick AVM modules — resolve the latest stable version live (see references/avm-modules.md)
4. Apply naming + tags — CAF table above; load references/naming-full-examples.md for length-constrained resources
5. Apply security baseline — see Quick Reference; load references/security-baseline-full.md when AVM parameters surface deprecation
6. Run the VNet planning gate — when the trigger contract holds (see VNet Planning Baseline above). Skip when decisions.vnet_planning_mode = deferred (sandbox only). Contract: references/vnet-planning.md
7. Apply cost monitoring — see Quick Reference; load references/cost-alerts-baseline.md for the full cost contract
8. Validate — npm run validate:iac-security-baseline + lint:bicep / terraform fmt && validate

Output Rules & Checklist

Before saving: confirm output path is agent-output/{project}/, all 4 required tags are present, uniqueSuffix is wired into globally-unique names, and region defaults match the table above.

Reference Index

Load these on demand — do NOT read all at once: