## Why
OS package remotes (rpm/deb/apk) fetch many small files and benefit from spreading upstream load across mirrors and surviving a mirror outage. A remote may now set a **`mirrorlist`** of additional upstream base URLs. The effective upstream pool is **`[base_url] + mirrorlist`**, which the shared proxy engine load-balances **round-robin** and, on a network error/timeout/5xx, **fails over** to the next mirror before returning an error. Selection happens in the engine, so it works for every provider that reaches upstream.
**Backward compatible:** `base_url` stays a plain string (providers read it unchanged), and a remote with **no mirrorlist behaves exactly as today** (single attempt, same error path).
## How
- `models.Remote.Mirrorlist` (`[]string`, `json:"mirrorlist,omitempty"`) + `UpstreamPool()` = `[base_url] + mirrorlist`.
- `ValidateMirrorlist`: a non-empty mirrorlist is allowed **only** when `repo_type==remote` **and** `package_type ∈ {rpm, deb, alpine}`; each entry must be an http/https URL. Enforced in the v2 create/update handlers (400 otherwise); `base_url` stays required for remotes.
- Persist the mirrorlist in a new additive `mirrorlist TEXT[]` column (`remoteCols`/`scanRemote`/`CreateRemote`/`UpdateRemote`); the `base_url` column is unchanged.
- Engine keeps a per-remote round-robin cursor over the pool; the fetch/head/revalidate upstream calls run in a failover loop that narrows the remote to one selected mirror per attempt. Only network errors and 5xx fail over (404/403/… return as-is). The circuit breaker stays keyed per remote and trips only after all mirrors fail.
## Scope
Round-robin + failover only, restricted to **remote rpm/deb/apk** repos. Least-connections and a per-remote strategy selector are a **follow-up PR**.
## Tests
- Unit: model JSON round-trip + validation gating (rejected on non-rpm/deb/apk and on local, accepted on rpm/deb/apk, bad URL rejected), engine round-robin/failover/no-mirrorlist-unchanged, DB mirrorlist round-trip. `make test` (`go test -race`) green.
- Docker acceptance (`e2e-docker`, `dockere2e` tag, wired into `docker-e2e.sh`): round-robin distribution across two mock upstreams, failover past a dead primary, no-mirrorlist regression, and a **real `dnf` makecache + install** through a two-mirror rpm remote whose `base_url` is dead. All four pass locally.
Reviewed-on: #121
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>
ArtifactAPI
Caching proxy for package repositories. Single Go binary, 10 package types, content-addressable storage, managed by Terraform.
Quick Start
# Start backing services
docker compose up -d postgres redis minio
# Build and run
make build
./bin/artifactapi
# Frontend (separate container or dev server)
cd ui && npm install && npm run dev
API: http://localhost:8000 | Frontend: http://localhost:5173
Package Types
| Type | Mutable (auto-detected) | Immutable (auto-detected) |
|---|---|---|
generic |
nothing | everything |
docker |
tag manifests, /tags/list |
blobs, digest manifests |
helm |
index.yaml |
.tgz charts |
pypi |
simple/* index pages |
.whl, .tar.gz |
npm |
package metadata | .tgz tarballs |
rpm |
repomd.xml, repodata/* |
.rpm |
alpine |
APKINDEX.tar.gz |
.apk |
puppet |
v3/modules/*, v3/releases* |
.tar.gz |
terraform |
*/versions |
*/download/*/* |
goproxy |
@v/list, @latest |
.info, .mod, .zip |
github_rpm |
repodata/* (synthesized) |
.rpm (redirected) |
Providers classify paths automatically. Users only configure what to proxy and TTLs.
github_rpm — GitHub releases as a yum repo (metadata-only, no precache)
A github_rpm remote turns a GitHub repo's releases into a real dnf/yum
repository without ever caching the packages. It scans releases for .rpm
assets, derives each package's metadata (NEVRA, requires/provides/conflicts/
obsoletes, files, checksum) and synthesizes repodata/ on the fly. Package
metadata comes from a ranged GET of just the RPM header (the header sits at
the front of the file, so the whole package is never downloaded); the sha256
checksum comes from the GitHub asset digest when present, else a one-time
lazy stream. Derived metadata is cached (keyed by asset) so repodata generation
is served from primed DB rows, never a cold on-demand derive.
Each package's <location> points back at the remote, which 302-redirects
the download to the releases_remote — an existing generic github.com remote
that streams the actual bytes. dnf follows the redirect transparently.
Background syncer
A single process-wide background syncer keeps every github_rpm remote's
derived metadata current off the client request path:
- Prime on create. Creating a
github_rpmremote enqueues a background prime scan, so its metadata is derived right away without blocking the create call. The firstdnfrequest is served from cache. If a request arrives before the prime lands, it returns a retryable503(withRetry-After) rather than serving an empty repo or blocking on a multi-minute derive. - Periodic re-check, driven by
mutable_ttl. Each remote is re-checked for new or changed releases no more often than itsmutable_ttl. New/changed assets are derived incrementally; assets already cached are never re-fetched, and assets that disappear upstream are pruned. - ETag / 304 conditional requests. The releases-list
ETagis stored per remote and sent asIf-None-Match; a304 Not Modifiedmeans nothing changed and the syncer derives nothing. GitHub does not count304conditional responses against the rate limit, so an unchanged repo is nearly free — this is the main lever keeping GitHub traffic low. - Global rate limit. Every GitHub call (releases list + each ranged asset
header GET) passes through a single token-bucket limiter shared across all
remotes, so GitHub is never hammered. Configure a token (
password) on the remote for the higher authenticated rate limit (~5000/hr vs ~60/hr unauthenticated). - Multi-replica coordination. State is shared through the database. Before a
periodic scan a replica must atomically claim a per-remote lease
(
github_rpm_sync_state:last_synced_at,etag,sync_lease_owner,sync_lease_expires); only the winner scans. This bounds total GitHub load to ~once permutable_ttlregardless of replica count, and the sharedetaglets any replica issue the conditional request.
# Backend that serves the actual .rpm bytes from github.com.
resource "artifactapi_remote_generic" "github" {
name = "github"
base_url = "https://github.com"
patterns = [
"acme/tools/releases/download/.*\\.rpm$", # allowlist the repo's release assets
]
}
resource "artifactapi_remote_github_rpm" "acme-tools" {
name = "acme-tools"
base_url = "https://api.github.com/repos/acme/tools" # the releases API root
releases_remote = "github" # backend for downloads
mutable_ttl = 3600 # release re-scan interval
# Optional: restrict which release assets become packages (regex on filename).
patterns = [".*\\.x86_64\\.rpm$", ".*\\.noarch\\.rpm$"]
# Optional: a token for private repos / higher API rate limits.
# password = "ghp_..."
}
dnf config: baseurl=https://artifactapi.example/api/v1/remote/acme-tools.
The repo is multi-arch (no $basearch needed) — dnf selects matching packages
from the synthesized metadata.
GitHub authentication
Anonymous GitHub is capped at 60 requests/hour and cannot read private repositories. Configure a server-level GitHub credential to raise the ceiling to roughly 5000 requests/hour and to read private-repo release assets. The credential is a process-wide machine identity applied by default to every outbound GitHub request — the releases scan, the ranged asset-header fetches, and the generic-github byte proxy that streams private release assets.
The credential is read from the environment (deliver it from a Vault or Kubernetes secret). It is never stored per-remote in the database, never returned by any API, and never logged. Configure exactly one mode.
Precedence. A remote's own username/password credential still wins for
that remote's requests; the server credential is the default for everything else.
With no credential configured at all, requests stay anonymous (current behavior).
Partial configuration (e.g. an App id with no private key) is a startup error
— artifactapi fails closed rather than silently falling back to anonymous.
Both modes share the syncer's single global rate limiter, so a token simply raises the effective GitHub ceiling; the default limiter settings stay safe.
Mode 1 — Personal Access Token (minimum viable, recommended for free accounts)
Set GITHUB_TOKEN. It is sent as Authorization: Bearer <token>.
Recommended free-account setup — a fine-grained PAT scoped to just the target repositories:
- GitHub → Settings → Developer settings → Personal access tokens → Fine-grained tokens → Generate new token.
- Limit Repository access to the specific repo(s) serving releases.
- Grant repository permissions Contents: Read-only and Metadata: Read-only (Metadata is mandatory and auto-selected).
A classic PAT with the repo scope also works but is broader than necessary.
GITHUB_TOKEN=github_pat_xxxxxxxx
Mode 2 — GitHub App installation token (proper machine identity)
A GitHub App is not tied to a personal account and can be created and installed on
free personal repos. artifactapi mints a short-lived RS256 JWT from the app
private key, exchanges it at POST /app/installations/{id}/access_tokens for a
~1-hour installation access token, caches that token, and refreshes it a few
minutes before expiry (thread-safe, single-flighted).
- GitHub → Settings → Developer settings → GitHub Apps → New GitHub App.
- Under Permissions → Repository permissions grant Contents: Read-only (Metadata: Read-only is implied).
- Generate a private key (downloads a PEM) and note the App ID.
- Install the App on the account and select the target repositories, then read
the Installation ID from the installation URL
(
.../settings/installations/<installation-id>).
GITHUB_APP_ID=123456
GITHUB_APP_INSTALLATION_ID=7654321
GITHUB_APP_PRIVATE_KEY_PATH=/etc/artifactapi/github-app.pem
# or inline PEM (e.g. mounted from a secret):
# GITHUB_APP_PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\n...\n-----END RSA PRIVATE KEY-----"
Terraform
Remotes and virtuals are managed by Terraform. Each package type has its own resource:
resource "artifactapi_remote_generic" "github" {
name = "github"
base_url = "https://github.com"
immutable_ttl = 0
mutable_ttl = 7200
patterns = [
"ducaale/xh/.*/xh-.*-x86_64-unknown-linux-musl.tar.gz$",
"mikefarah/yq/.*/yq_linux_amd64$",
]
mutable_patterns = [
".*/archive/refs/heads/.*\\.tar\\.gz$",
]
}
resource "artifactapi_remote_docker" "dockerhub" {
name = "dockerhub"
base_url = "https://registry-1.docker.io"
immutable_ttl = 0
mutable_ttl = 300
ban_tags_enabled = true
ban_tags = ["latest"]
patterns = [
"^library/postgres",
"^library/redis",
]
}
resource "artifactapi_remote_helm" "jetstack" {
name = "jetstack"
base_url = "https://charts.jetstack.io"
immutable_ttl = 0
mutable_ttl = 3600
}
resource "artifactapi_virtual" "helm" {
name = "helm"
package_type = "helm"
members = [artifactapi_remote_helm.jetstack.name]
}
Provider: terraform-provider-artifactapi
Serving providers as a registry
A local terraform repo is a real provider registry: upload
terraform-provider-{type}_{version}_{os}_{arch}.zip files under
{namespace}/{type}/, and Terraform installs them from a bare source address —
no .terraformrc mirror config:
terraform {
required_providers {
artifactapi = {
source = "artifactapi.k8s.syd1.au.unkin.net/<repo>/<type>"
version = "0.1.2"
}
}
}
The Terraform namespace segment is the artifactapi repo name; the provider is
matched by type. The registry serves service discovery
(/.well-known/terraform.json), the providers.v1 version/download endpoints,
and a GPG-signed SHA256SUMS per the provider registry protocol.
Signing needs a GPG key. By default artifactapi generates one on first start and
stores it in the database (signing_keys table), so every replica shares it and
there's nothing to provision. To bring your own key instead, point
TF_SIGNING_KEY_PATH at an armored private key (optionally
TF_SIGNING_KEY_PASSPHRASE), which takes precedence over the generated one.
TF_PROVIDER_PROTOCOLS (default 5.0,6.0) sets the advertised plugin protocols.
Local docker registry
A local docker repo is a real container registry, not a mirror: it serves the
Docker Registry HTTP API V2 for both push and pull, so any client (docker,
podman, skopeo, buildah) can use it directly.
docker tag myapp:latest artifactapi.k8s.syd1.au.unkin.net/docker-internal/myapp:latest
docker push artifactapi.k8s.syd1.au.unkin.net/docker-internal/myapp:latest
docker pull artifactapi.k8s.syd1.au.unkin.net/docker-internal/myapp:latest
The first path segment after /v2/ is the artifactapi repo name; the remainder
is the image name. Blobs and manifests are stored through the shared
content-addressable store (deduplicated by digest, reaped by GC once
unreferenced); tags are mutable references and re-pushing a tag moves it. Blob
uploads support both the monolithic and chunked (POST/PATCH/PUT) flows.
Access Control
| Field | Default | Behaviour |
|---|---|---|
patterns |
empty (proxy all) | If set, only matching paths are proxied. Acts as allowlist. |
blocklist |
empty | Matching paths always denied. Checked first. |
mutable_patterns |
empty | Override: force paths to mutable TTL. |
immutable_patterns |
empty | Override: force paths to immutable TTL. |
No patterns + no blocklist = open proxy. Provider handles mutability classification automatically.
API
Proxy (v1)
GET /api/v1/remote/{name}/{path} Proxy/cache artifact
GET /api/v1/virtual/{name}/{path} Virtual repo (merged index)
GET /v2/{name}/{path} Docker Registry v2
Management (v2)
GET/POST /api/v2/remotes List / create remotes
GET/PUT/DELETE /api/v2/remotes/{name} Read / update / delete remote
GET/DELETE /api/v2/remotes/{name}/objects Browse / evict cached objects
GET /api/v2/stats Overview stats
GET /api/v2/health Service health
POST /api/v2/probe Test a remote (fetch without streaming to client)
GET /api/v2/events SSE event stream
Architecture
PostgreSQL ─── config (remotes, virtuals), artifact metadata, access log
Redis ─── TTL keys, fetch locks, circuit breaker state
S3/MinIO ─── content-addressable blob storage (blobs/sha256/{hash})
S3 client supports MinIO, Ceph RGW, and AWS S3 (via minio-go).
Environment Variables
| Variable | Default | Description |
|---|---|---|
LISTEN_ADDR |
:8000 |
Server listen address |
DBHOST |
localhost |
PostgreSQL host |
DBPORT |
5432 |
PostgreSQL port |
DBUSER |
artifacts |
PostgreSQL user |
DBPASS |
PostgreSQL password | |
DBNAME |
artifacts |
PostgreSQL database |
REDIS_URL |
redis://localhost:6379 |
Redis URL |
MINIO_ENDPOINT |
localhost:9000 |
S3 endpoint |
MINIO_ACCESS_KEY |
S3 access key | |
MINIO_SECRET_KEY |
S3 secret key | |
MINIO_BUCKET |
artifacts |
S3 bucket |
MINIO_SECURE |
false |
Use HTTPS for S3 |
MINIO_REGION |
S3 region (AWS) | |
GITHUB_SYNC_RATE |
1 |
github_rpm syncer global GitHub request rate (req/s), shared across all remotes. 1/s = 3600/hr, under an authenticated token's ~5000/hr; unauthenticated (~60/hr) relies on ETag/304 |
GITHUB_SYNC_BURST |
5 |
Token-bucket burst for the shared limiter |
GITHUB_SYNC_WORKERS |
3 |
Concurrent github_rpm scan workers |
GITHUB_SYNC_POLL_INTERVAL |
60 |
Base scheduler tick in seconds; per-remote cadence is its mutable_ttl, enforced by the DB lease |
GITHUB_TOKEN |
Server-level GitHub PAT (fine-grained or classic), sent as Authorization: Bearer. Applies to every GitHub request; per-remote creds override it. See GitHub authentication |
|
GITHUB_APP_ID |
GitHub App id (App auth mode; mutually exclusive with GITHUB_TOKEN) |
|
GITHUB_APP_INSTALLATION_ID |
GitHub App installation id | |
GITHUB_APP_PRIVATE_KEY |
GitHub App private key, inline PEM | |
GITHUB_APP_PRIVATE_KEY_PATH |
GitHub App private key, file path (alternative to inline PEM) |
Development
make build # Build binary
make test # Unit tests
make e2e # E2E tests (needs Docker)
make lint # golangci-lint + go vet
make fmt # gofmt + goimports
TUI
./bin/artifactapi tui --endpoint http://localhost:8000