From 5ce745d104e82d836967e3bd9fd7af9602e76114 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Tue, 27 Oct 2020 13:30:12 +0100 Subject: refactor(main): Split HTTP handlers into separate functions There is a new handler coming up to fix #102 and I want to avoid falling into the classic Go trap of creating thousand-line functions. --- tools/nixery/config/pkgsource.go | 2 +- tools/nixery/main.go | 117 ++++++++++++++++++++------------------- 2 files changed, 62 insertions(+), 57 deletions(-) diff --git a/tools/nixery/config/pkgsource.go b/tools/nixery/config/pkgsource.go index 95236c4b0d15..380e664367e7 100644 --- a/tools/nixery/config/pkgsource.go +++ b/tools/nixery/config/pkgsource.go @@ -140,7 +140,7 @@ func pkgSourceFromEnv() (PkgSource, error) { } if git := os.Getenv("NIXERY_PKGS_REPO"); git != "" { - log.WithField("repo", git).Info("using NIx package set from git repository") + log.WithField("repo", git).Info("using Nix package set from git repository") return &GitSource{ repository: git, diff --git a/tools/nixery/main.go b/tools/nixery/main.go index 6cad93740978..92c602b1f79f 100644 --- a/tools/nixery/main.go +++ b/tools/nixery/main.go @@ -53,8 +53,8 @@ var version string = "devel" // routes required for serving images, since pushing and other such // functionality is not available. var ( - manifestRegex = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/manifests/([\w|\-|\.|\_]+)$`) - layerRegex = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/blobs/sha256:(\w+)$`) + manifestTagRegex = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/manifests/([\w|\-|\.|\_]+)$`) + layerRegex = regexp.MustCompile(`^/v2/([\w|\-|\.|\_|\/]+)/blobs/sha256:(\w+)$`) ) // Downloads the popularity information for the package set from the @@ -112,75 +112,80 @@ type registryHandler struct { state *builder.State } -func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { - // Acknowledge that we speak V2 with an empty response - if r.RequestURI == "/v2/" { - return - } +// 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") - // Serve the manifest (straight from Nix) - manifestMatches := manifestRegex.FindStringSubmatch(r.RequestURI) - if len(manifestMatches) == 3 { - imageName := manifestMatches[1] - imageTag := manifestMatches[2] + image := builder.ImageFromName(name, tag) + buildResult, err := builder.BuildImage(r.Context(), h.state, &image) - log.WithFields(log.Fields{ - "image": imageName, - "tag": imageTag, - }).Info("requesting image manifest") + if err != nil { + writeError(w, 500, "UNKNOWN", "image build failure") - image := builder.ImageFromName(imageName, imageTag) - buildResult, err := builder.BuildImage(r.Context(), h.state, &image) + log.WithError(err).WithFields(log.Fields{ + "image": name, + "tag": tag, + }).Error("failed to build image manifest") - if err != nil { - writeError(w, 500, "UNKNOWN", "image build failure") + return + } - log.WithError(err).WithFields(log.Fields{ - "image": imageName, - "tag": imageTag, - }).Error("failed to build image manifest") + // 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) - return - } + log.WithFields(log.Fields{ + "image": name, + "tag": tag, + "packages": buildResult.Pkgs, + }).Warn("could not find Nix packages") - // 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) + return + } - log.WithFields(log.Fields{ - "image": imageName, - "tag": imageTag, - "packages": buildResult.Pkgs, - }).Warn("could not find Nix packages") + // 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) + w.Write(manifest) +} - return - } +// serveLayer serves an image layer from storage (if it exists). +func (h *registryHandler) serveLayer(w http.ResponseWriter, r *http.Request, digest string) { + storage := h.state.Storage + err := storage.ServeLayer(digest, r, w) + if err != nil { + log.WithError(err).WithFields(log.Fields{ + "layer": digest, + "backend": storage.Name(), + }).Error("failed to serve layer from storage backend") + } +} - // 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) - w.Write(manifest) +// 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 } - // Serve an image layer. For this we need to first ask Nix for - // the manifest, then proceed to extract the correct layer from - // it. + // Build & serve a manifest by tag + manifestMatches := manifestTagRegex.FindStringSubmatch(r.RequestURI) + if len(manifestMatches) == 3 { + h.serveManifestTag(w, r, manifestMatches[1], manifestMatches[2]) + return + } + + // Serve an image layer layerMatches := layerRegex.FindStringSubmatch(r.RequestURI) if len(layerMatches) == 3 { - digest := layerMatches[2] - storage := h.state.Storage - err := storage.ServeLayer(digest, r, w) - if err != nil { - log.WithError(err).WithFields(log.Fields{ - "layer": digest, - "backend": storage.Name(), - }).Error("failed to serve layer from storage backend") - } - + h.serveLayer(w, r, layerMatches[2]) return } -- cgit 1.4.1