Fix attachments not displaying inline with Google Cloud Storagesh-fix-attachments-inline

There were several issues:

1. With Google Cloud Storage, we can't override the Content-Type with
Response-Content-Type once it is set. Setting the value to
`application/octet-stream` doesn't buy us anything.

2. CarrierWave and fog-google need to support query parameters:
https://github.com/fog/fog-google/pull/409/files, https://github.com/carrierwaveuploader/carrierwave/pull/2332/files

3. Workhorse also needs to remove the Content-Type header in the request
(https://gitlab.com/gitlab-org/gitlab-workhorse/blob/ef80978ff89e628c8eeb66556720e30587d3deb6/internal/objectstore/object.go#L66),
or we'll get a 403 error when uploading due to signed URLs not matching the headers:
https://gitlab.com/gitlab-org/gitlab-workhorse/merge_requests/294

Closes #49957

4 files changed, 21 insertions, 5 deletions

diff --git a/app/controllers/concerns/send_file_upload.rb b/app/controllers/concerns/send_file_upload.rb
index 237c93daee8..8d98eea3c5d 100644
--- a/app/controllers/concerns/send_file_upload.rb
+++ b/app/controllers/concerns/send_file_upload.rb
@@ -1,7 +1,9 @@
 module SendFileUpload
   def send_upload(file_upload, send_params: {}, redirect_params: {}, attachment: nil, disposition: 'attachment')
     if attachment
-      redirect_params[:query] = { "response-content-disposition" => "#{disposition};filename=#{attachment.inspect}" }
+      # Response-Content-Type will not override an existing Content-Type in Google Cloud Storage
+      redirect_params[:query] = { "response-content-disposition" => "#{disposition};filename=#{attachment.inspect}",
+                                  "response-content-type" => guess_content_type(attachment) }
       # By default, Rails will send uploads with an extension of .js with a
       # content-type of text/javascript, which will trigger Rails'
       # cross-origin JavaScript protection.
@@ -18,4 +20,12 @@ module SendFileUpload
       redirect_to file_upload.url(**redirect_params)
     end
   end
+
+  def guess_content_type(filename)
+    mime_type = MIME::Types.type_for(filename)
+
+    return "application/octet-stream" unless mime_type
+
+    mime_type.first.content_type
+  end
 end
diff --git a/changelogs/unreleased/sh-fix-attachments-inline.yml b/changelogs/unreleased/sh-fix-attachments-inline.yml
new file mode 100644
index 00000000000..2926edca97a
--- /dev/null
+++ b/changelogs/unreleased/sh-fix-attachments-inline.yml
@@ -0,0 +1,5 @@
+---
+title: Fix attachments not displaying inline with Google Cloud Storage
+merge_request: 21265
+author:
+type: fixed
diff --git a/config/initializers/fog_google_https_private_urls.rb b/config/initializers/fog_google_https_private_urls.rb
index f92e623a5d2..682b1050c68 100644
--- a/config/initializers/fog_google_https_private_urls.rb
+++ b/config/initializers/fog_google_https_private_urls.rb
@@ -7,9 +7,9 @@ module Fog
     class GoogleXML
       class File < Fog::Model
         module MonkeyPatch
-          def url(expires)
+          def url(expires, options = {})
             requires :key
-            collection.get_https_url(key, expires)
+            collection.get_https_url(key, expires, options)
           end
         end
 
diff --git a/lib/object_storage/direct_upload.rb b/lib/object_storage/direct_upload.rb
index 61a69e7ffe4..99f6ded7638 100644
--- a/lib/object_storage/direct_upload.rb
+++ b/lib/object_storage/direct_upload.rb
@@ -62,7 +62,7 @@ module ObjectStorage
 
     # Implements https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectGET.html
     def get_url
-      connection.get_object_url(bucket_name, object_name, expire_at)
+      connection.get_object_https_url(bucket_name, object_name, expire_at)
     end
 
     # Implements https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectDELETE.html
@@ -156,7 +156,8 @@ module ObjectStorage
     end
 
     def upload_options
-      { 'Content-Type' => 'application/octet-stream' }
+      # Any headers also have to be reflected in object.go in Workhorse as well
+      {}
     end
 
     def connection