refactor(nixery): Modernise structure of binaries r/4106

Nixery is going to gain a new binary (used for building images without
a registry server); to prepare for this the server binary has moved to
cmd/server and the Nix build logic has been updated to wrap this
binary and set the required environment variables.

Change-Id: I9b4f49f47872ae76430463e2fcb8f68114070f72
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5603
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

1 files changed, 0 insertions, 281 deletions

diff --git a/tools/nixery/main.go b/tools/nixery/main.go
deleted file mode 100644
index 8fe1679cfa..0000000000
--- a/tools/nixery/main.go
+++ /dev/null
@@ -1,281 +0,0 @@
-// Copyright 2022 The TVL Contributors
-// SPDX-License-Identifier: Apache-2.0
-
-// The nixery server implements a container registry that transparently builds
-// container images based on Nix derivations.
-//
-// The Nix derivation used for image creation is responsible for creating
-// objects that are compatible with the registry API. The targeted registry
-// protocol is currently Docker's.
-//
-// When an image is requested, the required contents are parsed out of the
-// request and a Nix-build is initiated that eventually responds with the
-// manifest as well as information linking each layer digest to a local
-// filesystem path.
-package main
-
-import (
-	"context"
-	"crypto/sha256"
-	"encoding/json"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"net/http"
-	"regexp"
-
-	"github.com/google/nixery/builder"
-	"github.com/google/nixery/config"
-	"github.com/google/nixery/layers"
-	"github.com/google/nixery/logs"
-	mf "github.com/google/nixery/manifest"
-	"github.com/google/nixery/storage"
-	log "github.com/sirupsen/logrus"
-)
-
-// ManifestMediaType is the Content-Type used for the manifest itself. This
-// corresponds to the "Image Manifest V2, Schema 2" described on this page:
-//
-// https://docs.docker.com/registry/spec/manifest-v2-2/
-const manifestMediaType string = "application/vnd.docker.distribution.manifest.v2+json"
-
-// This variable will be initialised during the build process and set
-// to the hash of the entire Nixery source tree.
-var version string = "devel"
-
-// Regexes matching the V2 Registry API routes. This only includes the
-// routes required for serving images, since pushing and other such
-// functionality is not available.
-var (
-	manifestRegex = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/manifests/([\w|\-|\.|\_]+)$`)
-	blobRegex     = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/(blobs|manifests)/sha256:(\w+)$`)
-)
-
-// Downloads the popularity information for the package set from the
-// URL specified in Nixery's configuration.
-func downloadPopularity(url string) (layers.Popularity, error) {
-	resp, err := http.Get(url)
-	if err != nil {
-		return nil, err
-	}
-
-	if resp.StatusCode != 200 {
-		return nil, fmt.Errorf("popularity download from '%s' returned status: %s\n", url, resp.Status)
-	}
-
-	j, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return nil, err
-	}
-
-	var pop layers.Popularity
-	err = json.Unmarshal(j, &pop)
-	if err != nil {
-		return nil, err
-	}
-
-	return pop, nil
-}
-
-// Error format corresponding to the registry protocol V2 specification. This
-// allows feeding back errors to clients in a way that can be presented to
-// users.
-type registryError struct {
-	Code    string `json:"code"`
-	Message string `json:"message"`
-}
-
-type registryErrors struct {
-	Errors []registryError `json:"errors"`
-}
-
-func writeError(w http.ResponseWriter, status int, code, message string) {
-	err := registryErrors{
-		Errors: []registryError{
-			{code, message},
-		},
-	}
-	json, _ := json.Marshal(err)
-
-	w.WriteHeader(status)
-	w.Header().Add("Content-Type", "application/json")
-	w.Write(json)
-}
-
-type registryHandler struct {
-	state *builder.State
-}
-
-// Serve a manifest by tag, building it via Nix and populating caches
-// if necessary.
-func (h *registryHandler) serveManifestTag(w http.ResponseWriter, r *http.Request, name string, tag string) {
-	log.WithFields(log.Fields{
-		"image": name,
-		"tag":   tag,
-	}).Info("requesting image manifest")
-
-	image := builder.ImageFromName(name, tag)
-	buildResult, err := builder.BuildImage(r.Context(), h.state, &image)
-
-	if err != nil {
-		writeError(w, 500, "UNKNOWN", "image build failure")
-
-		log.WithError(err).WithFields(log.Fields{
-			"image": name,
-			"tag":   tag,
-		}).Error("failed to build image manifest")
-
-		return
-	}
-
-	// Some error types have special handling, which is applied
-	// here.
-	if buildResult.Error == "not_found" {
-		s := fmt.Sprintf("Could not find Nix packages: %v", buildResult.Pkgs)
-		writeError(w, 404, "MANIFEST_UNKNOWN", s)
-
-		log.WithFields(log.Fields{
-			"image":    name,
-			"tag":      tag,
-			"packages": buildResult.Pkgs,
-		}).Warn("could not find Nix packages")
-
-		return
-	}
-
-	// This marshaling error is ignored because we know that this
-	// field represents valid JSON data.
-	manifest, _ := json.Marshal(buildResult.Manifest)
-	w.Header().Add("Content-Type", manifestMediaType)
-
-	// The manifest needs to be persisted to the blob storage (to become
-	// available for clients that fetch manifests by their hash, e.g.
-	// containerd) and served to the client.
-	//
-	// Since we have no stable key to address this manifest (it may be
-	// uncacheable, yet still addressable by blob) we need to separate
-	// out the hashing, uploading and serving phases. The latter is
-	// especially important as clients may start to fetch it by digest
-	// as soon as they see a response.
-	sha256sum := fmt.Sprintf("%x", sha256.Sum256(manifest))
-	path := "layers/" + sha256sum
-	ctx := context.TODO()
-
-	_, _, err = h.state.Storage.Persist(ctx, path, mf.ManifestType, func(sw io.Writer) (string, int64, error) {
-		// We already know the hash, so no additional hash needs to be
-		// constructed here.
-		written, err := sw.Write(manifest)
-		return sha256sum, int64(written), err
-	})
-
-	if err != nil {
-		writeError(w, 500, "MANIFEST_UPLOAD", "could not upload manifest to blob store")
-
-		log.WithError(err).WithFields(log.Fields{
-			"image": name,
-			"tag":   tag,
-		}).Error("could not upload manifest")
-
-		return
-	}
-
-	w.Write(manifest)
-}
-
-// serveBlob serves a blob from storage by digest
-func (h *registryHandler) serveBlob(w http.ResponseWriter, r *http.Request, blobType, digest string) {
-	storage := h.state.Storage
-	err := storage.Serve(digest, r, w)
-	if err != nil {
-		log.WithError(err).WithFields(log.Fields{
-			"type":    blobType,
-			"digest":  digest,
-			"backend": storage.Name(),
-		}).Error("failed to serve blob from storage backend")
-	}
-}
-
-// ServeHTTP dispatches HTTP requests to the matching handlers.
-func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	// Acknowledge that we speak V2 with an empty response
-	if r.RequestURI == "/v2/" {
-		return
-	}
-
-	// Build & serve a manifest by tag
-	manifestMatches := manifestRegex.FindStringSubmatch(r.RequestURI)
-	if len(manifestMatches) == 3 {
-		h.serveManifestTag(w, r, manifestMatches[1], manifestMatches[2])
-		return
-	}
-
-	// Serve a blob by digest
-	layerMatches := blobRegex.FindStringSubmatch(r.RequestURI)
-	if len(layerMatches) == 4 {
-		h.serveBlob(w, r, layerMatches[2], layerMatches[3])
-		return
-	}
-
-	log.WithField("uri", r.RequestURI).Info("unsupported registry route")
-
-	w.WriteHeader(404)
-}
-
-func main() {
-	logs.Init(version)
-	cfg, err := config.FromEnv()
-	if err != nil {
-		log.WithError(err).Fatal("failed to load configuration")
-	}
-
-	var s storage.Backend
-
-	switch cfg.Backend {
-	case config.GCS:
-		s, err = storage.NewGCSBackend()
-	case config.FileSystem:
-		s, err = storage.NewFSBackend()
-	}
-	if err != nil {
-		log.WithError(err).Fatal("failed to initialise storage backend")
-	}
-
-	log.WithField("backend", s.Name()).Info("initialised storage backend")
-
-	cache, err := builder.NewCache()
-	if err != nil {
-		log.WithError(err).Fatal("failed to instantiate build cache")
-	}
-
-	var pop layers.Popularity
-	if cfg.PopUrl != "" {
-		pop, err = downloadPopularity(cfg.PopUrl)
-		if err != nil {
-			log.WithError(err).WithField("popURL", cfg.PopUrl).
-				Fatal("failed to fetch popularity information")
-		}
-	}
-
-	state := builder.State{
-		Cache:   &cache,
-		Cfg:     cfg,
-		Pop:     pop,
-		Storage: s,
-	}
-
-	log.WithFields(log.Fields{
-		"version": version,
-		"port":    cfg.Port,
-	}).Info("starting Nixery")
-
-	// All /v2/ requests belong to the registry handler.
-	http.Handle("/v2/", &registryHandler{
-		state: &state,
-	})
-
-	// All other roots are served by the static file server.
-	webDir := http.Dir(cfg.WebDir)
-	http.Handle("/", http.FileServer(webDir))
-
-	log.Fatal(http.ListenAndServe(":"+cfg.Port, nil))
-}