Use R2 bindings for grapher config CF functions (follow-up to #6132)

[danyx23]

Context

Follow-up to #6132.

PR #6132 (already merged) attempted to mitigate the issue by disabling HTTP caching on the R2 URL fetch path.
This PR is a separate follow-up branch created from master and switches grapher config reads in CF functions from HTTP requests to R2 bindings.

Description

This PR updates Cloudflare Functions grapher config loading to use R2 bucket bindings instead of fetching from https://grapher-configs*.owid.io/....

What changed:

• functions/_common/grapherTools.ts
  • Replace URL-based fetch() reads with R2Bucket.get() reads.
  • Preserve conditional fetch behavior using If-None-Match (onlyIf) so 304 can still be returned.
  • Keep primary + fallback lookup behavior, now via primary/fallback R2 bindings.
  • Preserve key construction with configured path prefixes (GRAPHER_CONFIG_R2_BUCKET_PATH, GRAPHER_CONFIG_R2_BUCKET_FALLBACK_PATH).
• functions/_common/env.ts
  • Add R2 binding env types for grapher configs.
  • Keep URL env vars present for possible rollback/experimentation.
• wrangler.jsonc
  • Add GRAPHER_CONFIG_R2_BUCKET and GRAPHER_CONFIG_R2_BUCKET_FALLBACK bindings for default/preview/production.
  • Set grapher-config bindings to "remote": true for local dev so Wrangler reads from real buckets instead of empty local emulation.
  • Keep existing URL vars in config.

Expected effect:

• Avoid Cloudflare internal HTTP cache behavior on the R2 URL fetch path.
• Read config objects directly through R2 bindings while preserving status semantics (200/304/404).

Screenshots / Videos / Diagrams

None (no UI changes).

Testing guidance

1. Start local CF functions (yarn startLocalCloudflareFunctions).
2. Request a known config endpoint, e.g. /grapher/life-expectancy.config.json.
3. Verify config is served from binding-backed lookup and returns expected status codes.
4. Optionally test with If-None-Match to verify 304 behavior.

Automated checks run:

• yarn fixPrettierChanged > /dev/null 2>&1 && yarn typecheck

• yarn testLintChanged

• yarn testPrettierChanged

• Does the change work in the archive?

• Does the staging experience have sign-off from product stakeholders?

Checklist

Before merging

• Google Analytics events were adapted to fit the changes in this PR
• Changes to CSS/HTML were checked on Desktop and Mobile Safari at all three breakpoints
• Changes to HTML were checked for accessibility concerns

[owidbot]

Quick links (staging server):

Site Dev	Site Preview	Admin	Wizard	Docs

Login: ssh owid@staging-site-cf-use-r2-bindings

• Site-screenshots: https://github.com/owid/site-screenshots/compare/cf-use-r2-bindings
• SVG tester: https://github.com/owid/owid-grapher-svgs/compare/cf-use-r2-bindings

Archive:

• Data page with archive citation
• Archived data page
• Archived grapher page
• Archived indicator-based explorer
• Archived grapher-based explorer
• Archived multidimensional data page
• Archived article

SVG tester:

Number of differences (graphers): 0 ✅
Number of differences (grapher views): skipped
Number of differences (mdims): skipped
Number of differences (explorers): skipped

Edited: 2026-02-20 20:56:41 UTC
Execution time: 1.22 seconds

[ikesau]

lgtm! etag and no etag paths both work locally :)

[ikesau]

_shouldCache should be completely removed now.

[danyx23]

Good call — removed _shouldCache and all related plumbing from fetchFromR2/fetchUnparsedGrapherConfig so no dead cache arg remains.

[ikesau]

These 2 vars can be removed?

[danyx23]

Yep, removed both URL vars from Env and from wrangler.jsonc (vars, preview.vars, and production.vars) since config fetch now uses R2 bindings directly.

[danyx23]

• ✅🤖 add grapher config endpoint e2e tests with local R2 #6196
• Use R2 bindings for grapher config CF functions (follow-up to #6132) #6133 👈 (View in Graphite)
• master

This stack of pull requests is managed by Graphite. Learn more about stacking.

[danyx23]

Merge activity

• Mar 6, 1:07 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Mar 6, 1:08 PM UTC: Graphite rebased this pull request as part of a merge.
• Mar 6, 1:09 PM UTC: @danyx23 merged this pull request with Graphite.