From fb3a497119222c20c523bc09a658f71dcff28d49 Mon Sep 17 00:00:00 2001
From: Rob Watson <rob@netflux.io>
Date: Thu, 9 Dec 2021 04:05:34 +0100
Subject: [PATCH] Add base URL to serve file system store objects over HTTP

---
 backend/.env.example        |  7 ++++-
 backend/cmd/clipper/main.go |  2 +-
 backend/config/config.go    | 55 +++++++++++++++++++++----------------
 backend/filestore/fs.go     |  3 +-
 4 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/backend/.env.example b/backend/.env.example
index cd14011..f42d85d 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -15,7 +15,12 @@ ASSETS_HTTP_ROOT=
 # NOTE: Enabling the file system store will disable serving assets over HTTP.
 FILE_STORE=filesystem
 
-# The base path for the file system store.
+
+# The base URL used for serving file store assets.
+# Example: http://localhost:8888
+FILE_STORE_HTTP_BASE_URL=
+
+# The root directory for the file system store.
 FILE_STORE_HTTP_ROOT=data/
 
 # AWS credentials, required for the S3 store.
diff --git a/backend/cmd/clipper/main.go b/backend/cmd/clipper/main.go
index 2df4c87..bd9c108 100644
--- a/backend/cmd/clipper/main.go
+++ b/backend/cmd/clipper/main.go
@@ -101,5 +101,5 @@ func buildFileStore(ctx context.Context, c config.Config, logger *zap.Logger) (m
 	}
 
 	logger.Info("Initializing file sysytem store")
-	return filestore.NewFileSystemStore(c.FileStoreHTTPRoot, "/")
+	return filestore.NewFileSystemStore(c.FileStoreHTTPRoot, c.FileStoreHTTPBaseURL)
 }
diff --git a/backend/config/config.go b/backend/config/config.go
index 568a120..01144f6 100644
--- a/backend/config/config.go
+++ b/backend/config/config.go
@@ -21,18 +21,19 @@ const (
 )
 
 type Config struct {
-	Environment        Environment
-	BindAddr           string
-	TLSCertFile        string
-	TLSKeyFile         string
-	DatabaseURL        string
-	FileStore          FileStore
-	FileStoreHTTPRoot  string
-	AWSAccessKeyID     string
-	AWSSecretAccessKey string
-	AWSRegion          string
-	S3Bucket           string
-	AssetsHTTPRoot     string
+	Environment          Environment
+	BindAddr             string
+	TLSCertFile          string
+	TLSKeyFile           string
+	DatabaseURL          string
+	FileStore            FileStore
+	FileStoreHTTPRoot    string
+	FileStoreHTTPBaseURL string
+	AWSAccessKeyID       string
+	AWSSecretAccessKey   string
+	AWSRegion            string
+	S3Bucket             string
+	AssetsHTTPRoot       string
 }
 
 func NewFromEnv() (Config, error) {
@@ -76,6 +77,11 @@ func NewFromEnv() (Config, error) {
 		return Config{}, fmt.Errorf("invalid FILE_STORE value: %s", fileStoreString)
 	}
 
+	fileStoreHTTPBaseURL := os.Getenv("FILE_STORE_HTTP_BASE_URL")
+	if fileStoreHTTPBaseURL == "" {
+		fileStoreHTTPBaseURL = "/"
+	}
+
 	var awsAccessKeyID, awsSecretAccessKey, awsRegion, s3Bucket, fileStoreHTTPRoot string
 	if fileStore == S3Store {
 		awsAccessKeyID = os.Getenv("AWS_ACCESS_KEY_ID")
@@ -106,17 +112,18 @@ func NewFromEnv() (Config, error) {
 	assetsHTTPRoot := os.Getenv("ASSETS_HTTP_ROOT")
 
 	return Config{
-		Environment:        env,
-		BindAddr:           bindAddr,
-		TLSCertFile:        tlsCertFile,
-		TLSKeyFile:         tlsKeyFile,
-		DatabaseURL:        databaseURL,
-		FileStore:          fileStore,
-		AWSAccessKeyID:     awsAccessKeyID,
-		AWSSecretAccessKey: awsSecretAccessKey,
-		AWSRegion:          awsRegion,
-		S3Bucket:           s3Bucket,
-		AssetsHTTPRoot:     assetsHTTPRoot,
-		FileStoreHTTPRoot:  fileStoreHTTPRoot,
+		Environment:          env,
+		BindAddr:             bindAddr,
+		TLSCertFile:          tlsCertFile,
+		TLSKeyFile:           tlsKeyFile,
+		DatabaseURL:          databaseURL,
+		FileStore:            fileStore,
+		AWSAccessKeyID:       awsAccessKeyID,
+		AWSSecretAccessKey:   awsSecretAccessKey,
+		AWSRegion:            awsRegion,
+		S3Bucket:             s3Bucket,
+		AssetsHTTPRoot:       assetsHTTPRoot,
+		FileStoreHTTPRoot:    fileStoreHTTPRoot,
+		FileStoreHTTPBaseURL: fileStoreHTTPBaseURL,
 	}, nil
 }
diff --git a/backend/filestore/fs.go b/backend/filestore/fs.go
index af9a66a..3ab6a90 100644
--- a/backend/filestore/fs.go
+++ b/backend/filestore/fs.go
@@ -63,7 +63,8 @@ func (s *FileSystemStore) GetObjectWithRange(ctx context.Context, key string, st
 
 // GetURL returns an HTTP URL for the provided file path.
 func (s *FileSystemStore) GetURL(ctx context.Context, key string) (string, error) {
-	url := url.URL{}
+	var url url.URL
+	url.Scheme = s.baseURL.Scheme
 	url.Host = s.baseURL.Host
 	url.Path = fmt.Sprintf("%s%s", s.baseURL.Path, key)
 	return url.String(), nil