The integration jobs for `mcp-multi-user-basic` and `mcp-login-flow`
were failing with HTTP 500s. Root cause: `get_settings()` builds a
fresh Settings on every call (not cached). Commits 3 and 4 set the
derived `enable_login_flow` / `enable_multi_user_basic_auth` flags as
a side effect of `detect_auth_mode`. detect_auth_mode runs once at
startup, against the Settings instance owned by `validate_configuration`.
Every per-request call site that does `settings = get_settings()` got
a fresh Settings with both flags at their default `False` (since the
env-var aliases were dropped), causing the multi-user dispatcher in
`context.py` to take the wrong branch and crash.
Fix: move the derivation into `Settings.__post_init__`. Every Settings
instance now carries correct flags from the moment it's constructed —
no caching needed, no mutation-after-construction race. detect_auth_mode
becomes a pure reader of the already-derived state.
The legacy env-var deprecation check moves with it. It also picks up
the reviewer's truthy-string fix: previously `os.getenv(legacy)` fired
for the literal string "false" (a non-empty Python string is truthy),
which would have errored on any user with a leftover
`ENABLE_LOGIN_FLOW=false` in their `.env`. The check now only fires
when the value lowercases to one of {"1", "true", "yes", "on"}.
- nextcloud_mcp_server/config.py: extend Settings.__post_init__ with
the legacy-deprecation block and the derived-flag derivation
(resolve mode from deployment_mode + username/password, set flags).
- nextcloud_mcp_server/config_validators.py: drop the
`_sync_derived_flags` helper (superseded by __post_init__). Drop the
legacy-env-var deprecation block (moved). `detect_auth_mode` is now
pure — no mutation. Drop the now-unused `import os`.
- tests/unit/test_config_validators.py: legacy-env-var tests now
expect `ValueError` at `Settings(...)` construction (via `get_settings()`),
not at `detect_auth_mode` call. Added two new tests:
* `test_legacy_env_var_check_ignores_falsy_strings` — pins the
truthy-string fix (reviewer round 2 finding).
* `test_derived_flags_stable_across_get_settings_calls` — regression
test pinning the integration-test fix (two consecutive
`get_settings()` calls return Settings instances with the same
derived flags).
Also reworked `test_login_flow_mode_auto_derives_enable_login_flow_flag`
to assert at-construction derivation (not the old mutation pattern).
- docs/configuration-migration-v2.md: dropped the duplicate
`MCP_DEPLOYMENT_MODE=multi_user_basic` line (review round 2 nit — a
sed artifact from commit 4).
- docs/ADR-021-configuration-consolidation.md: sed-replaced the in-body
`MCP_DEPLOYMENT_MODE=oauth_single_audience` examples with `login_flow`
(review round 2 nit — only the status header was updated in commit 4).
- tests/conftest.py: docstring comment for the multi-user-basic fixture
switched from `ENABLE_MULTI_USER_BASIC_AUTH=true` to
`MCP_DEPLOYMENT_MODE=multi_user_basic` (review round 2 nit).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
