Configuration Runtime Resolution

Configuration Runtime Resolution

Purpose

Use this skill when generated Caddyfiles rely on values resolved during provisioning. Runtime replacement is implemented in caddyfile_resolve.go and tested by caddyfile_resolve_test.go.

Keep this skill aligned with github.com/greenpau/go-authcrunch config shapes: some sections preserve raw encoded directive arguments and are revalidated after replacement, while others are typed structs where only selected fields are resolved.

Replacement Forms

Use Caddy replacer placeholders for environment-backed values:

password {env.SMTP_PASSWORD}
client_secret {env.OIDC_CLIENT_SECRET}
crypto key sign-verify {env.JWT_SHARED_KEY}

Use secrets manager lookups for values provided by security.secrets modules:

password "secrets:users/jsmith:password" overwrite
crypto key sign-verify "secrets:access_token:shared_secret"

Secret lookup syntax is:

secrets:<secret_id>:<key>

The secret_id must match the second argument of a secrets <plugin> <secret_id> block, and <key> must be returned by that secrets manager.

Secret lookups run after Caddy replacer expansion and must be the entire value. The parser accepts exactly three colon-separated parts, so the secret key cannot contain another colon.

What Gets Resolved

ResolveRuntimeAppConfig mutates the authcrunch app config, then calls the affected authcrunch Validate methods so derived configs are rebuilt. The app supplies a fresh config copy for each runtime; never run resolution on a serving graph. JSON inputs can omit optional portal UI and cookie settings. Resolve those fields only when present and leave their defaults to AuthCrunch. Reject null entries in typed component collections, including nested ACL, redirect, credential, and registration objects, before calling validators or constructors. app_config.go uses explicit typed validators and generic slice and map helpers for those checks, following the coding skill's prohibition on reflect. When upstream adds a component collection, extend its typed validator and unit/E2E coverage. The checks permit omitted optional objects and leave flexible parameter maps to the resolver. After substitution, decode local/LDAP/OAuth/SAML parameter maps into AuthCrunch's exported config types and check decoding errors and null objects. Some dispatch validators ignore JSON decoding errors; do not let a partially decoded user or provider config reach construction. Reuse upstream types and semantic validation instead of maintaining field allowlists here. Object lists in those maps must contain objects throughout; do not silently skip a null or scalar entry after the first object. Return field paths so malformed replacements fail without disrupting the active deployment. The unit tests in app_lifecycle_test.go and actual Caddy reload tests in app_lifecycle_e2e_test.go cover these JSON provisioning cases.

Guard raw instruction argument counts before calling AuthCrunch's dispatch parsers: a one-token crypto statement or messaging/registration kind statement can otherwise panic during provisioning. For crypto, credentials, messaging, registration and transform instructions, check resolved tokens before cfgutil.EncodeArgs, which trims trailing empty tokens. Reject empty arguments and report the field/statement index without including secret values. Keep command semantics in AuthCrunch. Include literal empty tokens and empty environment replacements in unit and Caddy reload rejection tests, verifying that the old deployment still authorizes requests.

Resolve these app config areas:

• state.directory: replace the original scalar in the private config copy, then run the shared state validator without creating files. Whole environment and secrets-manager references retain exact token boundaries; unresolved or empty replacements fail with a redacted error. See persistent runtime state.
• credentials.raw_credential_configs, messaging.raw_configs, and user_registration.raw_configs: decode each instruction, replace each argument independently, then re-encode it for AuthCrunch validation. A resolved value is one argument, including spaces, quotes, and newlines; it must not inject instruction syntax. Resolve secret references at the argument level, where the command word cannot hide them. Preserve single-token flags such as messaging passwordless. Invoke these parsing validators only when raw instructions are present. Empty sections and typed configurations restored without raw instructions are preserved; values in those typed sections must already be resolved.
• identity_stores[].params and identity_providers[].params: recursively replace map keys, string values, string lists, lists of maps, and nested lists supported by substitute. JSON booleans and floating-point numbers remain unchanged; do not assume arbitrary Go scalar or slice types are supported. List handling is bounded to the shapes in substitute, not an unrestricted recursive JSON walk.
• sso_providers[]: replace entity_id, cert_path, private_key_path, and each locations entry. Do not assume name or driver is replaced.
• authentication_portals[]: replace raw crypto key-store lines, user-transformer matcher/action encoded arguments, selected UI strings (logo_url, logo_description, meta fields, auto_redirect_url, custom CSS and JS paths, template paths, private link titles/links, static asset path, content type, and filesystem path), cookie path, cookie domain map keys, and per-domain domain/path values. Resolve domain-map keys into a fresh map and reject collisions before replacing the map; in-place key updates can silently overwrite settings or process a newly inserted key twice.
• authorization_policies[]: replace raw crypto key-store lines and direct oauth string fields (provider, public origin, base path and cookie names). Complete runtime-backed OAuth bodies live in oauth_authorization_directives, resolve each token once, and reparse before policy defaults/validation; typed oauth and deferred directives are mutually exclusive. Literal-only bodies adapt directly to typed config. See direct OAuth. The subsequent policy validation rebuilds crypto_key_store_config. For JWT-only policies, pin absent cookie names to AUTHP_SESSION_ID and the default access-cookie list before construction, preventing implicit cross-portal discovery. Never add those JWT defaults to direct OAuth policies.

Cookie Caddyfile statements containing runtime placeholders are held separately in App.PortalCookieDirectives (portal_cookie_directives in Caddy JSON), keyed by portal name. After ResolveRuntimeAppConfig, app provisioning resolves that portal's entire statement collection and applies one validated snapshot through the shared cookie parser and PortalConfig.ConfigureCookies. This supports runtime names, prefixes, domains, and attributes without partially validating an unresolved cookie config. The deferred snapshot replaces any existing typed cookie config and is applied after other replacement to avoid expanding substituted paths a second time. Literal-only statements adapt directly to typed cookie config. See cookie configuration. After replacement, legacy translation treats braces in a resolved path as data; it must not defer that statement again. Keep cookie values as tokens until that translation and lossless encoding; an intermediate EncodeArgs roundtrip can silently trim an invalid name's trailing whitespace. Reject CR/LF in saved cookie statements before decoding so additional records cannot hide settings. See the cookie skill for the exact argument-preservation checks and reload regressions.

Token refresh blocks with runtime references are preserved in App.PortalTokenRefreshDirectives (portal_token_refresh_directives). Resolve each argument once and attach the shared parser's *authn.TokenRefreshConfig before portal validation; do not also supply typed refresh_tokens for that portal. Defer that portal's complete cookie statements too, including literal ones, until the enabled refresh override is known: collision checks must use the effective names. Literal refresh blocks need no snapshot. Native JSON origin, base path, cookie name and individual realm values support replacement. See token refresh placeholders for numeric/state values, duplicate checks, and JSON restoration coverage.

OAuth provider statements with runtime references are also retained separately, in App.OAuthProviderDirectives (oauth_provider_directives in Caddy JSON). They pass shared validation during adaptation. App provisioning then resolves each original argument once and reparses the whole provider, replacing the adapted Params instead of substituting that already-normalized map. This keeps Google client-ID suffixes and driver-derived URLs from changing secret lookup keys. Snapshot names must identify exactly one OAuth provider. Shared duplicate, state, key-file, and typed-only-field validation remains authoritative after replacement. Substituted strings are data and are not expanded again. See the OAuth reference for boundaries and the unit/TLS E2E coverage. Keep this app-level snapshot when copying adapted JSON; ResolveRuntimeAppConfig alone accepts an AuthCrunch config and does not carry app-level snapshots.

The route plugins have separate runtime replacement: authenticate ... with {env.PORTAL} and authorize ... with {env.POLICY} resolve their portal or gatekeeper names during plugin provisioning, not in ResolveRuntimeAppConfig.

Do not claim every string in authcrunch.Config is walked. If a placeholder is needed in an unsupported typed field, add explicit resolver coverage and a fixture instead of assuming the existing recursive helper will reach it.

Unsupported app fields currently include portal and policy names, portal enabled identity store/provider/SSO references, trusted redirect configs, portal role sets and patterns, most token options, cookie names in typed portal JSON (use deferred cookie statements instead), authorization policy ACL rules, bypass configs, header injection configs, auth proxy raw config, auth URL and forbidden URL fields, and access-token or session-cookie name fields.