Registry UI

Registry UI is a self-contained browser for Docker Registry HTTP API V2 and OCI images. It ships as one static Go binary with an embedded frontend, an integrated same-origin registry proxy, and no runtime dependency on Node.js or Nginx.

The frontend keeps Registry UI's original page structure and navigation while adopting S3 Browser's visual system: colors, typography, spacing, radii, local Material Design SVG icons, menus, notifications, and responsive finish.

Features

• Browse repositories and tags with server-side metadata enrichment.
• Open a repository's only tag directly, without an intermediate tag page.
• Inspect full image/config digests, type-aware colorized runtime settings and labels, colorized build arguments/environment values, exposed ports, and every ordered history entry.
• Switch platform details in place, with per-platform size, creation time, and author directly in the selector.
• Read a merged numbered Dockerfile/history view with sticky line numbers and cumulative size, signed layer change, and date kept outside selectable source.
• See the all-platform content Size and tag digest directly below the tag title.
• Download a tag as a streamed OCI archive or the selected platform as a Docker archive accepted by docker image load.
• Optionally delete manifest references when deletion is enabled and supported upstream.
• Proxy Docker Registry V2 requests through the same origin at /v2/.
• Run behind one reverse-proxy path prefix.
• Expose /health, /healthz, and /ready, plus a binary health command suitable for scratch.
• Build static Linux amd64 and arm64 release archives with GoReleaser.

All frontend assets are embedded and served locally. The application uses no CDN, external font, HCL file, generated dist directory, or frontend build step.

Quick start

cd src
REGISTRY_URL=http://127.0.0.1:5000 go run .

Open:

http://127.0.0.1:8080/

REGISTRY_URL is the only supported upstream URL variable.

Integration test stack

The repository includes an isolated test environment equivalent in structure to S3 Browser:

cd test
docker compose up --build -d
./smoke.sh

Open http://localhost:8080/. The stack starts:

• the production Registry UI scratch image;
• a private Docker Distribution registry;
• a one-shot publisher that loads deterministic OCI single-platform and multi-platform fixtures.

Remove it completely with:

docker compose down -v

No external registry, Docker socket, production credential, or HCL configuration is required. See test/README.md.

Configuration

Configuration is environment-only.

Variable	Default	Description
REGISTRY_URL	http://registry:5000	Docker Registry upstream used by backend APIs and the /v2/* proxy.
PORT	8080	HTTP port when LISTEN_ADDR is unset.
LISTEN_ADDR	:$PORT	Complete HTTP listen address.
REGISTRY_USERNAME	empty	Optional upstream Basic Auth username.
REGISTRY_PASSWORD	empty	Optional upstream Basic Auth password.
REGISTRY_BASIC_AUTH	empty	Optional complete Basic authorization value.
REGISTRY_TOKEN	empty	Optional upstream Bearer token.
DELETE_IMAGES	false	Enables deletion when the upstream also supports it.
HEALTH_URL	local /healthz	URL used by registry-ui health.
HEALTH_TIMEOUT	2s	Timeout used by the health command.

REGISTRY_URL accepts HTTP, HTTPS, custom ports, and an upstream path prefix:

REGISTRY_URL=https://registry.example.com:5443/internal go run .

See docs/CONFIGURATION.md for authentication precedence and all runtime details.

Docker

Build the scratch image:

docker build \
  -f test/browser/Dockerfile \
  --target runtime \
  --build-arg VERSION=v1.0.0 \
  -t registry-ui:v1.0.0 \
  .

Run it:

docker run --rm \
  --name registry-ui \
  --read-only \
  -p 8080:8080 \
  -e REGISTRY_URL=http://registry:5000 \
  registry-ui:v1.0.0

The final container runs as UID/GID 65532, includes CA certificates for HTTPS registries, and uses the binary itself for health checks.

HTTP endpoints

Endpoint	Purpose
/	Registry browser.
/config.json, /api/config	Public frontend configuration.
/api/catalog	Enriched repository catalog.
/api/tags	Enriched tags for one repository.
/api/tag	Detailed image metadata.
/api/download	OCI image archive download.
/api/download/docker	Docker image archive download for one selected platform.
/api/delete	Manifest reference deletion.
/v2/	Same-origin Docker Registry proxy.
/health, /healthz, /ready	Process health endpoints.

Frontend and API URLs are relative, so the application supports a reverse-proxy prefix such as:

https://example.com/registry-ui/

Health command

registry-ui health
registry-ui health --quiet
registry-ui health --url http://127.0.0.1:8080/healthz --timeout 3s

Documentation

• Architecture
• Configuration
• Development and validation
• Image and manifest support
• Security model

Project structure

registry-ui/
├── .github/
│   └── workflows/
│       ├── ci.yaml
│       └── release.yaml
├── docs/
│   ├── ARCHITECTURE.md
│   ├── CONFIGURATION.md
│   ├── DEVELOPMENT.md
│   ├── IMAGE_SUPPORT.md
│   └── SECURITY.md
├── src/
│   ├── public/
│   │   ├── assets/
│   │   │   ├── css/
│   │   │   ├── icons/mdi/
│   │   │   └── js/
│   │   ├── favicon.svg
│   │   └── index.html
│   ├── go.mod
│   ├── main.go
│   └── main_test.go
├── test/
│   ├── browser/Dockerfile
│   ├── seed/
│   ├── docker-compose.yaml
│   ├── frontend-contract.mjs
│   ├── tag-detail-format.mjs
│   ├── README.md
│   └── smoke.sh
├── LICENSE
└── README.md

Development

Run the complete local verification:

cd src
test -z "$(gofmt -l *.go)"
go test -race ./...
go vet ./...
node --check public/assets/js/api.js
node --check public/assets/js/app.js
node --check ../test/tag-detail-format.mjs
node ../test/frontend-contract.mjs
node ../test/tag-detail-format.mjs
CGO_ENABLED=0 go build -tags=netgo,osusergo -trimpath .

See docs/DEVELOPMENT.md for fixture, integration, and release validation.

Release

Create and push a semantic version tag:

git tag -a v1.0.0 -m "registry-ui v1.0.0"
git push origin v1.0.0

The release workflow runs formatting, tests, vetting, frontend contracts, static compilation, and GoReleaser. It publishes Linux archives for amd64 and arm64 with a checksum file.

License

AGPL-3.0.