refactor(server): Convert existing log entries to structured format

This rewrites all existing log statements into the structured logrus
format. For consistency, all errors are always logged separately from
the primary message in a field called `error`.

Only the "info", "error" and "warn" severities are used.

1 files changed, 49 insertions, 11 deletions

diff --git a/tools/nixery/server/main.go b/tools/nixery/server/main.go
index 06de6a96a143..babf50790f64 100644
--- a/tools/nixery/server/main.go
+++ b/tools/nixery/server/main.go
@@ -68,7 +68,9 @@ var (
 // The Docker client is known to follow redirects, but this might not be true
 // for all other registry clients.
 func constructLayerUrl(cfg *config.Config, digest string) (string, error) {
-	log.Printf("Redirecting layer '%s' request to bucket '%s'\n", digest, cfg.Bucket)
+	log.WithFields(log.Fields{
+		"layer": digest,
+	}).Info("redirecting layer request to bucket")
 	object := "layers/" + digest
 
 	if cfg.Signing != nil {
@@ -90,13 +92,18 @@ func constructLayerUrl(cfg *config.Config, digest string) (string, error) {
 func prepareBucket(ctx context.Context, cfg *config.Config) *storage.BucketHandle {
 	client, err := storage.NewClient(ctx)
 	if err != nil {
-		log.Fatalln("Failed to set up Cloud Storage client:", err)
+		log.WithFields(log.Fields{
+			"error": err,
+		}).Fatal("failed to set up Cloud Storage client")
 	}
 
 	bkt := client.Bucket(cfg.Bucket)
 
 	if _, err := bkt.Attrs(ctx); err != nil {
-		log.Fatalln("Could not access configured bucket", err)
+		log.WithFields(log.Fields{
+			"error":  err,
+			"bucket": cfg.Bucket,
+		}).Fatal("could not access configured bucket")
 	}
 
 	return bkt
@@ -169,13 +176,24 @@ func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if len(manifestMatches) == 3 {
 		imageName := manifestMatches[1]
 		imageTag := manifestMatches[2]
-		log.Printf("Requesting manifest for image %q at tag %q", imageName, imageTag)
+
+		log.WithFields(log.Fields{
+			"image": imageName,
+			"tag":   imageTag,
+		}).Info("requesting image manifest")
+
 		image := builder.ImageFromName(imageName, imageTag)
 		buildResult, err := builder.BuildImage(h.ctx, h.state, &image)
 
 		if err != nil {
 			writeError(w, 500, "UNKNOWN", "image build failure")
-			log.Println("Failed to build image manifest", err)
+
+			log.WithFields(log.Fields{
+				"image": imageName,
+				"tag":   imageTag,
+				"error": err,
+			}).Error("failed to build image manifest")
+
 			return
 		}
 
@@ -184,7 +202,13 @@ func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		if buildResult.Error == "not_found" {
 			s := fmt.Sprintf("Could not find Nix packages: %v", buildResult.Pkgs)
 			writeError(w, 404, "MANIFEST_UNKNOWN", s)
-			log.Println(s)
+
+			log.WithFields(log.Fields{
+				"image":    imageName,
+				"tag":      imageTag,
+				"packages": buildResult.Pkgs,
+			}).Error("could not find Nix packages")
+
 			return
 		}
 
@@ -205,7 +229,11 @@ func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		url, err := constructLayerUrl(&h.state.Cfg, digest)
 
 		if err != nil {
-			log.Printf("Failed to sign GCS URL: %s\n", err)
+			log.WithFields(log.Fields{
+				"layer": digest,
+				"error": err,
+			}).Error("failed to sign GCS URL")
+
 			writeError(w, 500, "UNKNOWN", "could not serve layer")
 			return
 		}
@@ -215,28 +243,38 @@ func (h *registryHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	log.Printf("Unsupported registry route: %s\n", r.RequestURI)
+	log.WithFields(log.Fields{
+		"uri": r.RequestURI,
+	}).Info("unsupported registry route")
+
 	w.WriteHeader(404)
 }
 
 func main() {
 	cfg, err := config.FromEnv()
 	if err != nil {
-		log.Fatalln("Failed to load configuration", err)
+		log.WithFields(log.Fields{
+			"error": err,
+		}).Fatal("failed to load configuration")
 	}
 
 	ctx := context.Background()
 	bucket := prepareBucket(ctx, &cfg)
 	cache, err := builder.NewCache()
 	if err != nil {
-		log.Fatalln("Failed to instantiate build cache", err)
+		log.WithFields(log.Fields{
+			"error": err,
+		}).Fatal("failed to instantiate build cache")
 	}
 
 	var pop layers.Popularity
 	if cfg.PopUrl != "" {
 		pop, err = downloadPopularity(cfg.PopUrl)
 		if err != nil {
-			log.Fatalln("Failed to fetch popularity information", err)
+			log.WithFields(log.Fields{
+				"error":  err,
+				"popURL": cfg.PopUrl,
+			}).Fatal("failed to fetch popularity information")
 		}
 	}