Set ContentType when loading objects from disk

Closes #531.

Dockerfile

@@ -11,6 +11,7 @@ ENV CGO_ENABLED=0
 RUN go build -o fake-gcs-server
 
 FROM alpine:3.14.0
+RUN apk add --no-cache mailcap
 COPY --from=builder /code/fake-gcs-server /bin/fake-gcs-server
 RUN /bin/fake-gcs-server -h
 EXPOSE 4443

ci/Dockerfile

@@ -1,4 +1,5 @@
 FROM alpine:3.14.0
 
+RUN apk add --no-cache mailcap
 ADD fake-gcs-server /bin/fake-gcs-server
 ENTRYPOINT ["/bin/fake-gcs-server", "-data", "/data"]

main.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"log"
+	"mime"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -91,11 +92,12 @@ func objectsFromBucket(localBucketPath, bucketName string) ([]fakestorage.Object
 				return fmt.Errorf("could not read file %q: %w", path, err)
 			}
 			objects = append(objects, fakestorage.Object{
-				BucketName: bucketName,
-				Name:       objectKey,
-				Content:    fileContent,
-				Crc32c:     checksum.EncodedCrc32cChecksum(fileContent),
-				Md5Hash:    checksum.EncodedMd5Hash(fileContent),
+				BucketName:  bucketName,
+				Name:        objectKey,
+				ContentType: mime.TypeByExtension(filepath.Ext(path)),
+				Content:     fileContent,
+				Crc32c:      checksum.EncodedCrc32cChecksum(fileContent),
+				Md5Hash:     checksum.EncodedMd5Hash(fileContent),
 			})
 		}
 		return nil

main_test.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"mime"
 	"os"
 	"testing"
 
@@ -17,7 +18,10 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+const testContentType = "text/plain; charset=utf-8"
+
 func TestMain(m *testing.M) {
+	mime.AddExtensionType(".txt", testContentType)
 	const emptyBucketDir = "testdata/basic/empty-bucket"
 	err := ensureEmptyDir(emptyBucketDir)
 	if err != nil {
@@ -44,9 +48,10 @@ func TestGenerateObjectsFromFiles(t *testing.T) {
 			folder: "testdata/basic",
 			expectedObjects: []fakestorage.Object{
 				{
-					BucketName: "sample-bucket",
-					Name:       "some_file.txt",
-					Content:    []byte("Some amazing content to be loaded"),
+					BucketName:  "sample-bucket",
+					Name:        "some_file.txt",
+					Content:     []byte("Some amazing content to be loaded"),
+					ContentType: testContentType,
 				},
 			},
 			expectedEmptyBuckets: []string{"empty-bucket"},
@@ -56,19 +61,22 @@ func TestGenerateObjectsFromFiles(t *testing.T) {
 			folder: "testdata/multi-level",
 			expectedObjects: []fakestorage.Object{
 				{
-					BucketName: "some-bucket",
-					Name:       "a/b/c/d/e/f/object1.txt",
-					Content:    []byte("this is object 1\n"),
+					BucketName:  "some-bucket",
+					Name:        "a/b/c/d/e/f/object1.txt",
+					Content:     []byte("this is object 1\n"),
+					ContentType: testContentType,
 				},
 				{
-					BucketName: "some-bucket",
-					Name:       "a/b/c/d/e/f/object2.txt",
-					Content:    []byte("this is object 2\n"),
+					BucketName:  "some-bucket",
+					Name:        "a/b/c/d/e/f/object2.txt",
+					Content:     []byte("this is object 2\n"),
+					ContentType: testContentType,
 				},
 				{
-					BucketName: "some-bucket",
-					Name:       "root-object.txt",
-					Content:    []byte("r00t\n"),
+					BucketName:  "some-bucket",
+					Name:        "root-object.txt",
+					Content:     []byte("r00t\n"),
+					ContentType: testContentType,
 				},
 			},
 		},
@@ -85,24 +93,28 @@ func TestGenerateObjectsFromFiles(t *testing.T) {
 			folder: "testdata/chaos",
 			expectedObjects: []fakestorage.Object{
 				{
-					BucketName: "bucket1",
-					Name:       "object1.txt",
-					Content:    []byte("object 1\n"),
+					BucketName:  "bucket1",
+					Name:        "object1.txt",
+					Content:     []byte("object 1\n"),
+					ContentType: testContentType,
 				},
 				{
-					BucketName: "bucket1",
-					Name:       "object2.txt",
-					Content:    []byte("object 2\n"),
+					BucketName:  "bucket1",
+					Name:        "object2.txt",
+					Content:     []byte("object 2\n"),
+					ContentType: testContentType,
 				},
 				{
-					BucketName: "bucket2",
-					Name:       "object1.txt",
-					Content:    []byte("object 1\n"),
+					BucketName:  "bucket2",
+					Name:        "object1.txt",
+					Content:     []byte("object 1\n"),
+					ContentType: testContentType,
 				},
 				{
-					BucketName: "bucket2",
-					Name:       "object2.txt",
-					Content:    []byte("object 2\n"),
+					BucketName:  "bucket2",
+					Name:        "object2.txt",
+					Content:     []byte("object 2\n"),
+					ContentType: testContentType,
 				},
 			},
 		},