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, 70 insertions, 15 deletions

diff --git a/tools/nixery/server/builder/cache.go b/tools/nixery/server/builder/cache.go
index 5b6bf078b228..916de3af168c 100644
--- a/tools/nixery/server/builder/cache.go
+++ b/tools/nixery/server/builder/cache.go
@@ -60,15 +60,25 @@ func (c *LocalCache) manifestFromLocalCache(key string) (json.RawMessage, bool)
 
 	f, err := os.Open(c.mdir + key)
 	if err != nil {
-		// TODO(tazjin): Once log levels are available, this
-		// might warrant a debug log.
+		// This is a debug log statement because failure to
+		// read the manifest key is currently expected if it
+		// is not cached.
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Debug("failed to read manifest from local cache")
+
 		return nil, false
 	}
 	defer f.Close()
 
 	m, err := ioutil.ReadAll(f)
 	if err != nil {
-		log.Printf("Failed to read manifest '%s' from local cache: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to read manifest from local cache")
+
 		return nil, false
 	}
 
@@ -86,7 +96,10 @@ func (c *LocalCache) localCacheManifest(key string, m json.RawMessage) {
 
 	err := ioutil.WriteFile(c.mdir+key, []byte(m), 0644)
 	if err != nil {
-		log.Printf("Failed to locally cache manifest for '%s': %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to locally cache manifest")
 	}
 }
 
@@ -123,18 +136,29 @@ func manifestFromCache(ctx context.Context, s *State, key string) (json.RawMessa
 
 	r, err := obj.NewReader(ctx)
 	if err != nil {
-		log.Printf("Failed to retrieve manifest '%s' from cache: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to retrieve manifest from bucket cache")
+
 		return nil, false
 	}
 	defer r.Close()
 
 	m, err := ioutil.ReadAll(r)
 	if err != nil {
-		log.Printf("Failed to read cached manifest for '%s': %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to read cached manifest from bucket")
+
+		return nil, false
 	}
 
 	go s.Cache.localCacheManifest(key, m)
-	log.Printf("Retrieved manifest for sha1:%s from GCS\n", key)
+	log.WithFields(log.Fields{
+		"manifest": key,
+	}).Info("retrieved manifest from GCS")
 
 	return json.RawMessage(m), true
 }
@@ -149,16 +173,27 @@ func cacheManifest(ctx context.Context, s *State, key string, m json.RawMessage)
 
 	size, err := io.Copy(w, r)
 	if err != nil {
-		log.Printf("failed to cache manifest sha1:%s: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to cache manifest to GCS")
+
 		return
 	}
 
 	if err = w.Close(); err != nil {
-		log.Printf("failed to cache manifest sha1:%s: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"manifest": key,
+			"error":    err,
+		}).Error("failed to cache manifest to GCS")
+
 		return
 	}
 
-	log.Printf("Cached manifest sha1:%s (%v bytes written)\n", key, size)
+	log.WithFields(log.Fields{
+		"manifest": key,
+		"size":     size,
+	}).Info("cached manifest to GCS")
 }
 
 // Retrieve a layer build from the cache, first checking the local
@@ -176,7 +211,11 @@ func layerFromCache(ctx context.Context, s *State, key string) (*manifest.Entry,
 
 	r, err := obj.NewReader(ctx)
 	if err != nil {
-		log.Printf("Failed to retrieve layer build '%s' from cache: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"layer": key,
+			"error": err,
+		}).Error("failed to retrieve cached layer from GCS")
+
 		return nil, false
 	}
 	defer r.Close()
@@ -184,14 +223,22 @@ func layerFromCache(ctx context.Context, s *State, key string) (*manifest.Entry,
 	jb := bytes.NewBuffer([]byte{})
 	_, err = io.Copy(jb, r)
 	if err != nil {
-		log.Printf("Failed to read layer build '%s' from cache: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"layer": key,
+			"error": err,
+		}).Error("failed to read cached layer from GCS")
+
 		return nil, false
 	}
 
 	var entry manifest.Entry
 	err = json.Unmarshal(jb.Bytes(), &entry)
 	if err != nil {
-		log.Printf("Failed to unmarshal layer build '%s' from cache: %s\n", key, err)
+		log.WithFields(log.Fields{
+			"layer": key,
+			"error": err,
+		}).Error("failed to unmarshal cached layer")
+
 		return nil, false
 	}
 
@@ -210,12 +257,20 @@ func cacheLayer(ctx context.Context, s *State, key string, entry manifest.Entry)
 
 	_, err := io.Copy(w, bytes.NewReader(j))
 	if err != nil {
-		log.Printf("failed to cache build '%s': %s\n", key, err)
+		log.WithFields(log.Fields{
+			"layer": key,
+			"error": err,
+		}).Error("failed to cache layer")
+
 		return
 	}
 
 	if err = w.Close(); err != nil {
-		log.Printf("failed to cache build '%s': %s\n", key, err)
+		log.WithFields(log.Fields{
+			"layer": key,
+			"error": err,
+		}).Error("failed to cache layer")
+
 		return
 	}
 }