sigma/AGENTS.md

AGENTS.md

Guidance for AI agents working in the sigma repository.

Project Overview

sigma is an OCI artifact storage and distribution system written in Go. It implements the OCI Distribution Specification 1.1 and acts as a private/public container registry. It supports docker registry v2 protocol, OCI images/artifacts/sboms, security scanning, registry proxy, namespace quotas, garbage collection, image signing (cosign), and image building via docker/podman/kubernetes.

• Module path: github.com/go-sigma/sigma
• Go version: 1.27.0 (godebug default=go1.27)
• License: Apache 2.0
• Entry point: main.go -> cmd.Execute()
• Default port: 3000
• Default credentials: sigma / Admin@123

Build & Run

# Build the binary (requires CGO_ENABLED=1 for sqlite)
make build

# Run via docker
docker run --name sigma -p 3000:3000 --rm tosone/sigma:nightly-alpine

# Run locally (needs a config file, default /etc/sigma/config.yaml)
go run . server -c conf/config.yaml

# Subcommands: server, worker, builder, distribution, tools

Build tags required for tests/lint/build:

netgo,timetzdata,exclude_graphdriver_btrfs,containers_image_openpgp

Common Commands

# Lint
make lint                       # runs golangci-lint + hadolint
make lint-go                    # golangci-lint only (timeout 10m)

# Tests (set CI_DATABASE_TYPE=sqlite3|turso|mysql|postgresql)
# Prefer turso for local unit-test verification.
CI_DATABASE_TYPE=turso go test -parallel 1 -failfast \
  -tags "netgo,timetzdata,exclude_graphdriver_btrfs,containers_image_openpgp" \
  -timeout 30m ./...

# Code generation
make gormgen                    # regenerate gorm models/queries from DB
make swagen                     # format Swagger comments and regenerate skill swagger.yaml
make migration-create MIGRATION_NAME=<name>   # new SQL migration

# Formatting
make sql-format                 # format all SQL migrations
make addlicense                 # add Apache license headers

# Vendor / clean
make vendor
make clean

Git Commit Messages

• Generated commit messages must use Conventional Commits and be written entirely in English, including the subject, body, footer, and verification notes.
• Include a body with what changed and why when the change needs more than a one-line subject, and put executed validation commands under Verification:.

Test Conventions

• Tests use github.com/stretchr/testify/require (preferred over assert).
• For DI setup in tests, construct a fresh dig.New() container and provide config.Configuration{} plus testkit.NewGin before calling factory{}.Initialize(digCon).
• Use testkit.NewGin() (in pkg/testkit/gin.go) to get a gin engine in TestMode; do not call gin.New() directly in tests.
• Repository tests must import the target repository domain package with a semantic repo-prefixed alias, such as reporegistry, reponamespace, or repouser.
• Generate cryptographic keys (e.g., Ed25519) at runtime in tests; do not hardcode base64 keys.
• Tests are excluded for generated or infrastructure-only packages such as pkg/api, pkg/dal/models, pkg/dal/query, pkg/dal/cmd, pkg/version, and various mocks subpackages.
• Some storage tests (pkg/storage/cos, pkg/storage/oss) are skipped on PRs and require secret env vars (COS_*, OSS_*).
• Mocks are generated via go.uber.org/mock and live alongside the code as *_mocks.go.

Code Conventions

Import aliases

• Repository package aliases use the repo prefix followed by the domain name, such as repouser, reponamespace, reporegistry, and repowebhook.
• Service package aliases use the svc prefix followed by the domain name, such as svcnamespace, svcrepository, svcmanifest, and svcaudit.
• Do not use suffix-style aliases such as userrepo, namespacesvc, or auditrepo.

Variable scope and unused parameters

• Do not shadow an outer err with err := ... in nested blocks, goroutines, or deferred cleanup functions. Use assignment (err = ...) when updating the outer error is intentional, or use a short local name such as e for isolated cleanup/logging errors.
• In deferred cleanup, log the cleanup error variable itself, not an unrelated outer err.
• If a required method signature includes an unused context.Context, name the parameter _ context.Context in the signature. Do not add _ = ctx inside the function body just to silence unused parameter checks.

Error handling

• Use errcode.AsType[T](err) (in pkg/server/errcode/astype.go) instead of errors.As(err, &e) for typed error assertions. The canonical usage: errcode.AsType[errcode.ErrCode](err).
• Handlers return error (echo-style) and are wrapped via server.Wrap(h) or server.WrapHandle(r, method, path, h). See pkg/server/adapter.go.
• Return errcode.NewHTTPError(c, ...) from handlers for structured HTTP errors.

Dependency Injection

• DI is powered by go.uber.org/dig. Handlers declare dig.In and request services by field.
• Resolve ad hoc dependencies with digCon.Invoke(func(deps ...) error { ... }) instead of adding global container helpers.
• Handler factories register routes via handlers.Routers.Register(path.Base(reflect.TypeFor[factory]().PkgPath()), &factory{}) in an init().

Handler structure

• Each handler package (e.g. pkg/server/handlers/systems) defines a Handler interface, a private handler struct embedding dig.In, and a factory{} with Initialize(dig.Container) error.
• The systems handler uses field SystemsService of type service.SystemsServiceFactory. Do not use a field named config.
• Routes are grouped under consts.APIV1 (i.e. /api/v1).

IDs & crypto

• All application IDs must be time-ordered UUIDv7 strings.
• Generate UUIDs through pkg/utils/uuid.NewV7String() instead of calling an external UUID package directly.
• pkg/utils/uuid is backed by the Go standard library uuid package.

Modernize Go

• Prefer modern Go idioms over legacy patterns. This project targets Go 1.27 and follows the modernizations that go fix applies. Run go fix ./... after a toolchain bump to keep the codebase current (use go fix -diff ./... to preview first). See commit feat: update with go fix modernize.
• Concretely, prefer:
  • any over interface{}.
  • the min/max builtins over hand-written if/else comparisons.
  • for i := range n over C-style for i := 0; i < n; i++ loops.
  • slices / maps stdlib helpers (e.g. slices.Contains, slices.Sort, maps.Keys) over manual loops and sort.Slice.
  • strings.Cut / strings.CutPrefix over strings.Index / HasPrefix + TrimPrefix slicing.
  • fmt.Appendf over []byte(fmt.Sprintf(...)).
  • reflect.TypeFor[T]() over reflect.TypeOf.
  • t.Context() in tests over context.WithCancel boilerplate.
• These are also reinforced elsewhere in this file: log/slog for logging (see Logging) and context.Context threaded through the call chain (see Tracing).

Configuration

• Config is loaded from YAML (default /etc/sigma/config.yaml, override with -c). See conf/config.yaml for the full schema.
• Supports sqlite3, turso, mysql, postgresql; redis (none/external); cache (inmemory/redis); workqueue (inmemory/redis/database); locker (inmemory/redis); storage (filesystem/s3/cos/oss); trace (enabled/endpoint/protocol/insecure/sampleRatio/serviceName).

Logging

• Uses the standard library log/slog. Get the logger via slog.Default() (global) or slog.FromContext(ctx) (context-aware, falls back to default).
• Configure the level via logger.SetLevel(levelStr) from pkg/logger — installs a slog.TextHandler writing to stdout with AddSource: true.
• For fatal errors, use logger.Fatal(msg, args...) from pkg/logger (logs at Error then os.Exit(1)); do not call slog.Error followed by os.Exit directly.
• The gorm adapter logger.ZLogger{} is wired in pkg/dal/dal.go.
• Avoid re-introducing log.Logger.WithContext(ctx) calls — they are no longer needed; slog's default global logger is used everywhere.

Tracing

• Distributed tracing is powered by OpenTelemetry. Initialization lives in pkg/telemetry/trace.go and is invoked from each long-lived subcommand (server, worker, distribution) via telemetry.Init(*config.GetConfig()). The builder subcommand is a one-shot CLI and intentionally skips trace init.
• The tracer provider is configured from the trace: section of the config: enabled, endpoint (OTLP collector), protocol (grpc or http), insecure (TLS off), sampleRatio (0..1), serviceName.
• Sampler is ParentBased(TraceIDRatioBased(sampleRatio)) — root spans respect the ratio, child spans always inherit the parent's sampling decision.
• Propagator is W3C TraceContext + Baggage.
• Instrumentation is attached at the integration points (no manual spans in handlers/services):
  • Gin: otelgin.Middleware(consts.AppName) is the first middleware in pkg/app/helper.go.
  • GORM: tracing.NewPlugin() from gorm.io/plugin/opentelemetry/tracing is applied to every gorm.Open site in pkg/dal/dal.go.
  • Redis: redisotel.InstrumentTracing(cli) is called in pkg/dal/redis/redis.go and pkg/infra/cache/cacher_redis.go.
  • Outbound HTTP (resty): the http.Client transport is wrapped with otelhttp.NewTransport(...) in pkg/distribution/clients/clients.go and pkg/background/daemon/webhook/webhook.go.
• Always pass context.Context through the call chain so spans propagate. Do not call context.Background() mid-request unless you intentionally want to break the trace.

Linting rules (.golangci.yml)

• Enabled linters: asciicheck, bidichk, bodyclose, copyloopvar, cyclop (max 50), gocritic, gosec, misspell, prealloc, unconvert, unparam, varnamelen, whitespace.
• Imports ordered by: standard, blank, default, github.com/go-sigma/sigma prefix, dot. (enforced by gci/goimports).
• cyclop is disabled for *_test.go.

Project Structure

cmd/                     CLI entrypoints (server, worker, builder, distribution, tools, cli)
main.go                  Program entry; calls cmd.Execute()
pkg/
  app/                   Application assembly layer
    bootstrap/           Bootstrapping (dig container, signing keys, initial user)
    distribution/        Distribution-only process startup
    server/              Server process startup
    worker/              Worker process startup
  api/                   HTTP/API DTOs
    enums/               Shared API and configuration enums
  background/            Background execution domain
    builder/             Image build backends (docker, kubernetes, podman)
    cronjob/             Scheduled jobs
    daemon/              Background daemons (gc, scan, webhook, transfer, coderepo)
  config/                Config structs & defaults
  consts/                 Constants (API paths, regex, HTTP codes, settings)
  dal/                   Data access layer
    models/              GORM models
    query/               Generated gorm/gen queries (do not hand-edit)
    repository/          Repository layer grouped by domain
      analytics/         Analytics metrics repositories
      audit/             Audit log repositories
      builder/           Builder repositories
      coderepo/          Source code repository repositories
      daemon/            Background daemon repositories
      namespace/         Namespace and namespace member repositories
      registry/          OCI registry repositories (artifact/blob/repository/tag)
      setting/           System setting repositories
      user/              User repositories
      webhook/           Webhook repositories
    migrations/          SQL migrations per DB (mysql/postgresql/sqlite3)
    redis/               Redis client
  server/
    adapter.go           Handler wrap/error dispatch
    errcode/             Error types, AsType generic, HTTP error mapping
    handlers/            HTTP handlers grouped by domain
      <domain>/
        handler.go       Handler interface + factory + route registration
        handler_test.go  Factory/DI test
        <action>.go      Individual route handlers
    middlewares/         authn, authz, etag, extractor, healthz, metrics
  service/               Business logic layer (interfaces + impls + mocks)
    password/, token/    Auth helpers
  authz/                 Authorizer, permission, resolver, cache
  distribution/          OCI distribution protocol domain
    clients/             Distribution/proxy clients
    reference/           Image reference helpers
    signing/             Cosign signing integration
  infra/                 Infrastructure modules
    cache/               Cache implementations
    lock/                Locker implementations
    registry/            Generic factory/implementation registries
    timewheel/           Time wheel module
    workq/               Work queue implementations
  logger/                slog setup + glog adapter
  testkit/               Test helpers (NewGin, CI database setup)
  telemetry/             OpenTelemetry tracer provider init + shutdown
  utils/                 Misc utilities
  validators/            Request validators
  version/               Build-time version info (set via -ldflags)
conf/                    Example config files & TLS certs
deploy/sigma/            Helm chart
build/                   Dockerfile and entrypoint for server/builder image targets
docs/                    VitePress documentation site
e2e/                     End-to-end test scripts
tools/skill/             External AI/CLI agent skills and packaged API specs

Directory rules:

• New repository code must be added to the matching pkg/dal/repository/<domain> package instead of the repository root.
• Handler package names must match their directory names.
• Handlers should not import pkg/background/* directly; expose background behavior through the service layer unless the code is an explicit startup or boundary adapter.

CI Workflows (.github/workflows/)

• lint.yml: Go 1.27 + Bun web build + golangci-lint v2.12.2 + hadolint on build/Dockerfile. Triggers on main/dev PRs.
• test.yml: Go 1.27 + Bun web build; runs application tests on PostgreSQL and database tests on sqlite3, turso, postgresql, and mysql. Uses MySQL 8.0, Postgres 15, Redis 7, and rs3 services. Uploads coverage to Coveralls.
• e2e.yml, image-build.yml, gh-pages.yml, codeql.yml: end-to-end, image build, docs deploy, security scan.

Important Files

• pkg/server/adapter.go - HandlerFunc + Wrap/WrapHandle + centralized error dispatch.
• pkg/server/errcode/astype.go - AsType[T error] generic helper.
• pkg/server/errcode/xerrors.go - NewHTTPError, ErrCode, HTTPErrCodeInternalError.
• pkg/dal/dig.go - DI registration for all repositories + authorizer.
• pkg/server/handlers/systems/handler.go - canonical handler example.
• pkg/testkit/gin.go - NewGin() test helper.
• pkg/telemetry/trace.go - OpenTelemetry tracer provider init + shutdown.
• Makefile - all build/lint/test/generation targets.
• .golangci.yml - lint configuration.

Things to Avoid

• Do not use errors.As directly when an errcode.AsType[T] variant exists.
• Do not introduce non-UUID or unordered UUID generators. Use pkg/utils/uuid.NewV7String() so new IDs remain UUIDv7 and time-ordered.
• Do not add a config field to handler structs; use the appropriate service factory field (e.g., SystemsService).
• Do not import the repository root package in tests; import the target repository domain package with a semantic alias.
• Do not hand-edit generated files under pkg/dal/query/*.gen.go; regenerate with make gormgen.
• Do not create new test files that hardcode cryptographic material; generate at runtime.
• Do not import github.com/rs/zerolog; use log/slog.
• Do not use interface{}; use any (see Modernize Go).
• Do not add log.Logger.WithContext(ctx) calls; use the context directly or slog.FromContext(ctx).
• Do not call telemetry.Init from the builder subcommand — it is a one-shot CLI and uses env vars, not the YAML config.
• Do not create manual spans in handlers/services; rely on the auto-instrumentation in pkg/telemetry and pkg/app/helper.go.