Every blob went through the multipart machinery: an S3 multipart started
on Docker's initial POST, a hold round trip per part, and a complete on
the hold that finished the multipart, HEADed the temp object, copied it
to its final key, and deleted the temp. For a 2KB config blob that was
three hold calls and six S3 operations. On production data 86% of
distinct layers and every config blob fit in a 16MB buffer, and 49% of
image manifests have no layer larger than that.
The writer now buffers up to 16MB (also the multipart part size) and
makes no hold call until it has to. A blob that never overflows the
buffer is written at Commit with a single presigned PUT to its final
key, via the hold's existing method=PUT presign; the multipart only
starts on the first flush. The hold's completeUpload does nothing the
direct path skips: quota, layer records, stats and scan dispatch all
hang off notifyManifest, which is unchanged.
The buffer starts empty and grows on demand, with the doubling capped so
capacity never overshoots 16MB: a config blob costs kilobytes, and only
layers that approach the threshold fill it.
Bytes are hashed as they arrive. Commit compares the computed sha256 to
the digest the client claimed before any network call, and returns
DIGEST_INVALID on mismatch, aborting a multipart if one was started.
Previously nothing verified the content, so a pusher could store wrong
bytes under a digest in the shared content-addressed space.
Tests observe request counts on a fake hold and fake S3 rather than
return values. The growth test streams in 24KB chunks because
power-of-two chunks land on 16MB by luck and hid an earlier weaker guard.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018Yf1ZVA7sXYhQNb9tCo1m5
did:plc Identity Support (pkg/hold/pds/did.go, pkg/hold/config.go, pkg/hold/server.go)
The big feature — holds can now use did:plc identities instead of only did:web. This adds:
- LoadOrCreateDID() — resolves hold DID by priority: config DID > did.txt on disk > create new
- CreatePLCIdentity() — builds a genesis operation, signs with rotation key, submits to PLC directory
- EnsurePLCCurrent() — on boot, compares local signing key + URL against PLC directory and auto-updates if they've drifted (requires rotation key)
- New config fields: did_method (web/plc), did, plc_directory_url, rotation_key_path
- GenerateDIDDocument() now uses the stored DID instead of always deriving did:web from URL
- NewHoldServer wired up to call LoadOrCreateDID instead of GenerateDIDFromURL
CAR Export/Import (pkg/hold/pds/export.go, pkg/hold/pds/import.go, cmd/hold/repo.go)
New CLI subcommands for repo backup/restore:
- atcr-hold repo export — streams the hold's repo as a CAR file to stdout
- atcr-hold repo import <file>... — reads CAR files, upserts all records in a single atomic commit. Uses a bulkImportRecords method that opens a delta session, checks each record for
create vs update, commits once, and fires repo events.
- openHoldPDS() helper to spin up a HoldPDS from config for offline CLI operations
Admin UI Fixes (pkg/hold/admin/)
- Logout changed from GET to POST — nav template now uses a <form method=POST> instead of an <a> link (prevents CSRF on logout)
- Removed return_to parameter from login flow — simplified redirect logic, auth middleware now redirects to /admin/auth/login without query params
Config/Deploy
- config-hold.example.yaml and deploy/upcloud/configs/hold.yaml.tmpl updated with the four new did:plc config fields
- go.mod / go.sum — added github.com/did-method-plc/go-didplc dependency
Evan JarrettandClaude Fable 5.1