fix: enforce known host values in azure.yaml schema

[huimiu]

What

Add an enum of the known host values to the per-service schema in both schemas/v1.0/azure.yaml.json and schemas/alpha/azure.yaml.json, mirroring the existing examples list.

Why

Fixes #8856. In VS Code (redhat YAML extension) the unified Foundry azure.yaml gave autocomplete but no validation squiggles. Root cause: host was a free-form type: string, so a misspelled host like azure.ai.projct was a valid string and matched no if/then branch — no error. yaml-language-server validates with ajv, so this reproduces exactly; with the enum, misspelled hosts now squiggle ("must be equal to one of the allowed values").

Scope

Minimal and low-risk: the enum mirrors the curated examples the schema already advertises, so every valid host still passes. containerapp-dotnet is intentionally excluded (internal-only host, not valid in azure.yaml). Unknown-field detection was intentionally left out of scope to avoid surfacing squiggles in existing azure.yaml files that rely on the schema's additionalProperties: true.

Verification

• ajv (same engine as the YAML extension): misspelled host → invalid; baseline Foundry sample, classic containerapp sample, and simple.azure.yaml → valid.
• CI checks pass locally: jsonlint and jsonschema2md on both schema files.

[github-actions]

📋 Prioritization Note

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[Copilot]

Pull request overview

This PR tightens the azure.yaml JSON schemas (v1.0 and alpha) by changing services.*.host from an unconstrained string to a fixed set of known host values, so YAML validation (e.g., VS Code redhat YAML via ajv) can flag misspellings that previously slipped through.

Changes:

• Add an enum for services.*.host in the v1.0 schema to enforce known host values.
• Add the same enum for services.*.host in the alpha schema to keep validation behavior consistent across schema versions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
schemas/v1.0/azure.yaml.json	Adds an enum of known host values to enforce schema validation for service hosts.
schemas/alpha/azure.yaml.json	Mirrors the same host enum enforcement in the alpha schema for parity.

[jongio]

The goal here (IDE squiggles on misspelled hosts) is good, but a strict enum conflicts with azd's extension architecture. parseServiceHost() in service_target.go:68-75 explicitly allows any non-empty host value through because extensions register custom service-target providers at runtime via gRPC. This makes the host field intentionally open-ended; locking it down in the schema means every extension-provided host will show a spurious validation error in the user's editor.

Beyond the extensibility concern (already noted by the earlier review), several of the proposed enum values don't actually correspond to registered service-target providers in the codebase or extension registry:

• microsoft.foundry
• azure.ai.project
• azure.ai.connection
• azure.ai.toolbox
• azure.ai.skill
• azure.ai.routine

None of these appear in the registry, extension providers declarations, or Go source as valid host identifiers. Only azure.ai.agent (from the azure.ai.agents extension) and the 6 built-in targets (appservice, containerapp, function, staticwebapp, aks, ai.endpoint) are actually resolvable today. Including unregistered names in the enum would validate misspelled-but-close values while still rejecting valid extension hosts not on the list.

A possible alternative: keep host as type: string (preserving extensibility) but expand the examples array so the YAML extension offers autocomplete for all known hosts without rejecting unknown ones.

[jongio]

Thanks for removing springapp, microsoft.foundry, and the redundant examples array. The updated description acknowledging extension hosts is also a good addition.

Two issues remain from my earlier review:

1. enum still breaks extensibility

The description says "hosts contributed by extensions are resolved by azd at runtime and may not be listed here," which is accurate, but enum in JSON Schema rejects any value not in the list. That means any extension-registered host that isn't listed will produce a spurious validation error in the editor. parseServiceHost() (service_target.go:68-75) explicitly allows any non-empty host value because extensions register custom service targets at runtime via gRPC. Using examples instead of enum would give autocomplete without rejecting unknown hosts.

2. Five enum values don't correspond to registered service-target providers

I checked every extension under cli/azd/extensions/:

• azure.ai.projects (capabilities: custom-commands, metadata) - no service-target-provider, no providers: section
• azure.ai.connections (capabilities: custom-commands, metadata) - same
• azure.ai.toolboxes (capabilities: custom-commands, metadata) - same
• azure.ai.skills (capabilities: custom-commands, metadata) - same
• azure.ai.routines (capabilities: custom-commands, metadata) - same

Only azure.ai.agents declares service-target-provider capability and registers azure.ai.agent as a provider. The other five names (azure.ai.project, azure.ai.connection, azure.ai.toolbox, azure.ai.skill, azure.ai.routine) aren't resolvable as host values today. Including them in an enum validates misspelled-but-close values while failing to catch actual typos in the names azd can resolve.

Suggestion: switch back to examples (keeps autocomplete, doesn't reject extension hosts), and trim the list to only the 7 hosts that are actually resolvable: appservice, containerapp, function, staticwebapp, aks, ai.endpoint, azure.ai.agent.

[jongio]

Two issues from my prior feedback remain unaddressed:

1. enum rejects valid extension hosts: parseServiceHost() (service_target.go:68-75) allows any non-empty host value because extensions register custom service-target providers at runtime via gRPC. enum in JSON Schema rejects any value not in the list, so every extension-provided host will show a spurious validation error in the editor. The description acknowledges this but enum still rejects them. Use examples instead to give autocomplete without blocking unknown hosts.

2. 5 enum values aren't registered service-target providers: azure.ai.project, azure.ai.connection, azure.ai.toolbox, azure.ai.skill, azure.ai.routine don't appear as service-target-provider capabilities in any extension manifest. Only azure.ai.agents declares that capability. Including unresolvable host names validates typo-adjacent values while rejecting valid extension hosts.

Suggested fix: revert to examples (preserves autocomplete, doesn't reject extension hosts) and trim to the 7 actually-resolvable hosts: appservice, containerapp, function, staticwebapp, aks, ai.endpoint, azure.ai.agent.

[jongio]

enum will reject any host value not in this list. Since extensions register arbitrary service-target providers at runtime (azure.ai.agents does this today), users of those extensions will get false validation errors in their editor. Switch back to examples so the YAML extension offers autocomplete for known hosts without rejecting unknown ones.