mirror of
https://tangled.org/evan.jarrett.net/at-container-registry
synced 2026-09-10 04:06:06 +00:00
Evan JarrettandClaude Opus 5
a63b839613
Go's net/http compresses nothing by default and the appview is served by a
raw Go server behind a load balancer that does not compress either, so
everything went out uncompressed: style.css at 180 KB, bundle.min.js at
105 KB, and the homepage HTML at 95 KB. Lighthouse put style.css alone at
1,768 ms of blocked first paint, and mobile Performance measured 77 against
98 on desktop, entirely on paint metrics (TBT 10ms, CLS 0).
klauspost/compress is already a direct dependency and ships gzhttp, so this
costs no new one. Brotli would save roughly 11 KB more across the three
largest assets in exchange for a runtime dependency, which is not worth it.
The /v2 skip is the part that needs care. The OCI registry API is mounted on
the same chi router as the UI (server.go:561), and container layers are
already gzipped tarballs, so compressing that path burns CPU for no gain.
The content-type allowlist would catch most of it, but /v2/* also serves
application/json for tag listings and errors, so the path check keeps the
registry out of the compression path entirely. The predicate matches the one
the domain-routing middleware already uses.
Measured against a local build, gzip vs identity:
/ 14,526 -> 4,298 71%
/css/style.css 183,990 -> 31,596 83%
/js/bundle.min.js 107,781 -> 32,648 70%
/icons.svg 26,360 -> 8,403 69%
total 332,657 -> 76,945 77%
Verified end to end against a running binary: UI and static responses carry
Content-Encoding: gzip with Vary: Accept-Encoding, /v2/ and /v2/*/tags/list
carry neither, and woff2 stays untouched. Tests cover both directions plus
the under-1 KB and no-Accept-Encoding cases.
HTTP/2 is the remaining half and cannot be fixed here: the load balancer
terminates TLS and negotiates no ALPN at all, which pins every request to
HTTP/1.1. That is an LB setting.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0124r73LT4qoFE82TqwH2Gu9