[yarikoptic-gitmate]

This is the follow-up planned in #1963. It adds a registry of the dandi-archive features which dandi-cli uses only where the server supports them, and adds the weekly survey and the disabling env var that it described.

What it adds

dandi/server_features.py

• ServerFeature records, for each feature:
  • a CODENAME;
  • a description, including what dandi-cli does without the feature;
  • links to the dandi-archive and dandi-cli issues/PRs;
  • base_version: the dandi-archive release the feature was developed on top of;
  • released_version: the release that added it, once known;
  • sense(client): a function that checks for the feature without changing anything on the server.
• The features are registered in SERVER_FEATURES.
• The module types the client as a small APIClient Protocol (api_url, session, server_info, get_url()) rather than importing dandi.dandiapi, which imports it; CodeQL flags the cycle even under TYPE_CHECKING.

DandiAPIClient.server_features decides, once per client:

• .supports("CODENAME") -> bool.
• .resolve() also says how the answer was reached: disabled, version, sensed or recorded.
• .record("CODENAME", supported) lets code that found out by using the feature update the answer.

How support is decided

1. Disabled, if the CODENAME is listed in DANDI_DEVEL_DISABLE_SERVER_FEATURES (comma- or space-separated), e.g. BULK_DELETE. Unknown names are warned about and ignored.

2. By version, only if /api/info/'s version is a clean dandi-archive release:

   • version >= released_version: supported;
   • version < released_version: not supported;
   • before a release is known, version <= base_version: not supported.

   Development versions (sandbox instances) and versions with a post or local part (forks) do not count as releases, because they can't be compared with dandi-archive's. EMBER reports 0.0.post1.dev7927+g9e4606812 and LINC 0.0.post6586+g39387b8, so in practice only DANDI's own instances are decided by version.

3. Otherwise by sense().

routes_endpoint(client, path) is a probe that does not modify anything. It sends OPTIONS to path and to a sibling path that no server has, then compares status and content type.

• Without the endpoint, both get Django's HTML 404.
• An existing endpoint answers in JSON (200, or 401 on servers that require login).
• Rate limiting (429), 5xx responses and connection errors count as "endpoint not there".

Registered feature: BULK_DELETE (dandi/dandi-archive#2920, which is unmerged and based on 1.0.19).

• Probed with routes_endpoint() on /dandisets/000000/versions/draft/assets/bulk-delete/.
• Nothing on master uses it yet. It is here for Use the bulk asset deletion endpoint for all asset deletion #1960, and so the survey can track deployment. See the notes below.
• An earlier version of this PR also registered ALLOWED_SCHEMA_VERSIONS and sent check_schema_version()'s fallback through the registry. Remove dandi-archive compatibility kludges that no known instance needs #1973 has since removed that fallback, so the merge with master dropped the entry and kept master's check_schema_version(). This PR no longer changes dandi/dandiapi.py beyond adding server_features.

Survey of known instances. test_survey[CODENAME] checks every instance in known_instances except the local Docker one.

• It prints a table, which is also written to the job summary.
• It fails once all instances support a feature, i.e. once the fallback and the registry entry can be removed.
• It is marked server_features_survey and skipped unless --server-features-survey is given.
• It runs from the new .github/workflows/server-features.yml: weekly (Mondays 05:23 UTC), on demand, and on PRs that touch the registry. Its run on this PR gave the table below.

Docs

• The DEVELOPMENT.md compatibility section now describes the registry as the way to do this, keeping Remove dandi-archive compatibility kludges that no known instance needs #1973's LINC paragraph and its rule for removing a fallback once no known instance needs it. It lists the registered features, and separately the older conditionals that are not decided per server.
• The env var, the marker, the pytest option and the workflow are documented in DEVELOPMENT.md.
• A Sphinx page for dandi.server_features is added.

Checked against live servers

The survey job on this PR, before the merge with master, produced:

Feature	dandi	dandi-sandbox	linc	linc-staging	ember-dandi	ember-dandi-sandbox
ALLOWED_SCHEMA_VERSIONS	yes (version)	yes (sensed)	no (sensed)	no (sensed)	yes (sensed)	yes (sensed)
BULK_DELETE	no (sensed)	no (sensed)	no (sensed)	no (sensed)	no (sensed)	no (sensed)

From the environment this was prepared in, only lincbrain.org was reachable; DANDI and EMBER hosts were blocked by its network policy.

• LINC and LINC staging: BULK_DELETE is no (sensed) (also after the merge), and they lack allowed_schema_versions.
• Probe on LINC:
  • routes_endpoint() returns True for routes LINC has (…/assets/paths/, /zarr/);
  • it returns False for …/assets/bulk-delete/ and for a made-up path.
• Not run locally: test_local_archive checks the probe against the Docker archive (dandiarchive/dandiarchive-api) in CI's dandi-api jobs. Docker Hub rate-limited the image pull here.

Notes

• Use the bulk asset deletion endpoint for all asset deletion #1960 could use the registry. It could call client.server_features.supports("BULK_DELETE") instead of inferring support from a 404. That 404 can't tell an old server from a missing version.
• Add bulk asset deletion endpoint dandi-archive#2920 changed since Use the bulk asset deletion endpoint for all asset deletion #1960 was written. Its latest commits no longer return 404 for assets missing from the version, and they return the number of removed assets. Use the bulk asset deletion endpoint for all asset deletion #1960's parsing of missing IDs from a 404 may need revisiting.
• Answers are kept per DandiAPIClient, like server_info. The DEVELOPMENT.md: require backward compatible support of new dandi-archive features #1963 plan suggested keying them by API URL across clients. Per client is simpler to reason about and to test, and the CLI uses one client per command; I can switch if preferred.
• Uploads to LINC fail the schema check, as Remove dandi-archive compatibility kludges that no known instance needs #1973 describes under "Not addressed here". This PR does not change that.
• Not registered:
  • the x-amz-tagging handling in Zarr upload, which senses from each presigned URL rather than once per server;
  • _get_instance()'s /server-info → /api/info/ fallback, which happens before a client has any server info.

Testing

• test_server_features.py (new, ai_generated):
  • 29 unit test cases covering the version rules (including LINC's and sandbox-style versions), sensing once per client, the env var, record(), unknown CODENAMEs, the probe's responses, registry hygiene, and the survey's report;
  • test_local_archive, against the Docker archive;
  • test_survey[BULK_DELETE].
• Locally:
  • the survey test passed with --server-features-survey (LINC rows no (sensed), others unreachable);
  • pre-commit and mypy are clean;
  • the docs build with -W;
  • the full local non-integration suite (-m "not obolibrary"), before the merge with master: 916 passed, 26 failed. All 26 failures are tests that need dandiarchive.org, which that environment's network policy blocks (proxy errors and timeouts); CI runs them with network access.
  • after the merge: test_server_features.py, the check_schema_version() and downgrade tests in test_dandiapi.py, the _check_attempts_and_sleep() tests, the survey, pre-commit, mypy and the docs build with -W all pass.

🤖 Generated with Claude Code

https://claude.ai/code/session_014sJtxzEPbSxycxetp4DquU

[codecov]

Codecov Report

❌ Patch coverage is 93.01471% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.97%. Comparing base (524479d) to head (9208adb).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
dandi/tests/test_server_features.py	88.41%	19 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1970      +/-   ##
==========================================
+ Coverage   90.88%   90.97%   +0.08%     
==========================================
  Files          92       94       +2     
  Lines       14244    14515     +271     
==========================================
+ Hits        12946    13205     +259     
- Misses       1298     1310      +12     

Flag	Coverage Δ
unittests	90.97% <93.01%> (+0.08%)	⬆️

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[yarikoptic]

ok, I will back-shelf it for now, especially since bulk delete is not even finalized yet... may be later we will work on this.