storage manager: add backblaze b2 backend.

Gemfile

@@ -46,6 +46,8 @@ gem 'builder'
 gem 'puma'
 gem 'scenic'
 gem 'ipaddress'
+gem 'fog-core'
+gem 'fog-backblaze', require: 'fog/backblaze'
 
 # needed for looser jpeg header compat
 gem 'ruby-imagespec', :require => "image_spec", :git => "https://github.com/r888888888/ruby-imagespec.git", :branch => "exif-fixes"

Gemfile.lock

@@ -153,6 +153,7 @@ GEM
       railties (>= 3.2, < 6.1)
     equalizer (0.0.11)
     erubi (1.9.0)
+    excon (0.70.0)
     factory_bot (5.1.1)
       activesupport (>= 4.2.0)
     faraday (0.17.1)
@@ -161,6 +162,14 @@ GEM
     ffi (1.11.3)
     ffi (1.11.3-x64-mingw32)
     flamegraph (0.9.5)
+    fog-backblaze (0.3.0)
+      fog-core (>= 1.40, < 3)
+    fog-core (2.1.2)
+      builder
+      excon (~> 0.58)
+      formatador (~> 0.2)
+      mime-types
+    formatador (0.2.5)
     get_process_mem (0.2.5)
       ffi (~> 1.0)
     globalid (0.4.2)
@@ -444,6 +453,8 @@ DEPENDENCIES
   factory_bot
   ffaker
   flamegraph
+  fog-backblaze
+  fog-core
   httparty
   ipaddress
   jquery-rails

app/logical/storage_manager/cloud.rb

@@ -0,0 +1,27 @@
+class StorageManager::Cloud < StorageManager
+  attr_reader :bucket, :client, :fog_options
+
+  def initialize(bucket, client: nil, fog_options: {}, **options)
+    @bucket = bucket
+    @fog_options = fog_options
+    @client = client || Fog::Storage.new(**fog_options)
+    super(**options)
+  end
+
+  def store(io, path)
+    data = io.read
+    client.put_object(bucket, path, data)
+  end
+
+  def delete(path)
+    client.delete_object(bucket, path)
+  end
+
+  def open(path)
+    file = Tempfile.new(binmode: true)
+    response = client.get_object(bucket, path)
+    file.write(response.body)
+    file.rewind
+    file
+  end
+end