refactor(server): Introduce pluggable interface for storage backends

This abstracts over the functionality of Google Cloud Storage and
other potential underlying storage backends to make it possible to
replace these in Nixery.

The GCS backend is not yet reimplemented.

1 files changed, 5 insertions, 40 deletions

diff --git a/tools/nixery/server/config/config.go b/tools/nixery/server/config/config.go
index 6c1baafce8..ad6dff4043 100644
--- a/tools/nixery/server/config/config.go
+++ b/tools/nixery/server/config/config.go
@@ -18,42 +18,11 @@
 package config
 
 import (
-	"io/ioutil"
 	"os"
 
-	"cloud.google.com/go/storage"
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/oauth2/google"
 )
 
-// Configure GCS URL signing in the presence of a service account key
-// (toggled if the user has set GOOGLE_APPLICATION_CREDENTIALS).
-func signingOptsFromEnv() *storage.SignedURLOptions {
-	path := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
-	if path == "" {
-		return nil
-	}
-
-	key, err := ioutil.ReadFile(path)
-	if err != nil {
-		log.WithError(err).WithField("file", path).Fatal("failed to read service account key")
-	}
-
-	conf, err := google.JWTConfigFromJSON(key)
-	if err != nil {
-		log.WithError(err).WithField("file", path).Fatal("failed to parse service account key")
-	}
-
-	log.WithField("account", conf.Email).Info("GCS URL signing enabled")
-
-	return &storage.SignedURLOptions{
-		Scheme:         storage.SigningSchemeV4,
-		GoogleAccessID: conf.Email,
-		PrivateKey:     conf.PrivateKey,
-		Method:         "GET",
-	}
-}
-
 func getConfig(key, desc, def string) string {
 	value := os.Getenv(key)
 	if value == "" && def == "" {
@@ -70,13 +39,11 @@ func getConfig(key, desc, def string) string {
 
 // Config holds the Nixery configuration options.
 type Config struct {
-	Bucket  string                    // GCS bucket to cache & serve layers
-	Signing *storage.SignedURLOptions // Signing options to use for GCS URLs
-	Port    string                    // Port on which to launch HTTP server
-	Pkgs    PkgSource                 // Source for Nix package set
-	Timeout string                    // Timeout for a single Nix builder (seconds)
-	WebDir  string                    // Directory with static web assets
-	PopUrl  string                    // URL to the Nix package popularity count
+	Port    string    // Port on which to launch HTTP server
+	Pkgs    PkgSource // Source for Nix package set
+	Timeout string    // Timeout for a single Nix builder (seconds)
+	WebDir  string    // Directory with static web assets
+	PopUrl  string    // URL to the Nix package popularity count
 }
 
 func FromEnv() (Config, error) {
@@ -86,10 +53,8 @@ func FromEnv() (Config, error) {
 	}
 
 	return Config{
-		Bucket:  getConfig("BUCKET", "GCS bucket for layer storage", ""),
 		Port:    getConfig("PORT", "HTTP port", ""),
 		Pkgs:    pkgs,
-		Signing: signingOptsFromEnv(),
 		Timeout: getConfig("NIX_TIMEOUT", "Nix builder timeout", "60"),
 		WebDir:  getConfig("WEB_DIR", "Static web file dir", ""),
 		PopUrl:  os.Getenv("NIX_POPULARITY_URL"),