ctan

An hourly mirror of all of CTAN on Cloudflare R2, served at https://ctan.ijosh.com/ with every CTAN path at the root. About 511,000 files and 140 GB.

How to use

Your request served to https://mirrors.ctan.org/ might be redirected to this mirror automatically (once I apply for official mirror status). Until then, the full mirror of CTAN is served from https://ctan.ijosh.com/.

TeX Live and TinyTeX both use tlmgr:

tlmgr option repository https://ctan.ijosh.com/systems/texlive/tlnet/
tlmgr update --self --all

For a fresh install, give the installer the same URL:

install-tl -repository https://ctan.ijosh.com/systems/texlive/tlnet/

Browse it: any directory URL, https://ctan.ijosh.com/systems/knuth/, lists what the mirror holds there.

To go back to CTAN's mirror rotation: tlmgr option repository ctan.

How it works

On an hourly schedule this GitHub action is triggered and runs the following pipeline. Every step is a task in Taskfile.yml:

1. clock list state rebuild — stamp the hour, list CTAN's master (dante), and fetch the listing the previous run left in the bucket, rebuilding it if it went missing.
2. diff plan — take what upstream has and the state lacks, and split it into batches of at most 4 GB. The mirror is never a local copy: the runner has 14 GB, the tree has 140.
3. tlpdb batches — per batch, rsync the files, check the signed TeX Live control files against a pinned key fingerprint and every package container against the tlpdb's checksums, upload, and write the new state. A run that dies repeats one batch, not all.
4. delete reconcile — drop the keys that left upstream; once a day, sweep the bucket against the state for anything neither owns.
5. index — redraw the directory pages the run changed, since R2 has no listings.
6. smoke report ping — read a sample of the run's keys back over the public domain, summarise what landed, and ping healthchecks.io. Silence is the alert.

Is it fresh?

curl -s https://ctan.ijosh.com/timestamp

Why use this?

I built this for myself. mirrors.ctan.org hands out a different volunteer mirror on every request, and sooner or later one is overloaded, stale, or unreachable — which breaks the CI that builds my documents. This is one hostname on Cloudflare's network of 300+ cities, a short and consistent hop wherever you are. It costs under $2 a month to run: R2 bills for storage and nothing for bandwidth, so traffic doesn't move the bill.

Want your own?

1. Fork this repo and create an R2 bucket named ctan with a custom domain pointing at it.
2. Set HOST in Taskfile.yml to that domain — the only line in the repo that names the hostname.
3. Add the four repository secrets below. They are the whole requirement.
4. Actions -> sync -> Run workflow, with seed checked and max_batches at 40. The first run uploads everything (about 140 GB, a few hours); every run after it pushes the hourly delta. Storage past R2's free 10 GB costs about $1.95 a month.
5. Uncomment the schedule: block in sync.yml with a minute per hour to run the sync automation.

Secret	What it is
AWS_ACCESS_KEY_ID	R2 API token with Object Read & Write on the bucket
AWS_SECRET_ACCESS_KEY	That token's secret
AWS_ENDPOINT_URL	https://<account-id>.r2.cloudflarestorage.com
AWS_REGION	auto

To test or run locally:

task run -- task --dry sync
task run -- task sync

Reference

Please see docs/reference.md for the full repo documentation. It contains:

• Baseline — the measured tree, churn, busiest hours
• Limits — R2, Cloudflare, Actions, dante
• Cost — the bill line by line
• Monitoring — the healthchecks.io check and its settings
• Runbook — failed runs, seeds, rebuilds, rotations
• Zone configuration — every rule, with its expression
• Why directory pages — listings drawn under two keys

Pull requests are welcome.

MIT licensed. Built by Josh Vaughen.