Helper method for storage path stripping

app/workers/post_receive.rb

@@ -3,20 +3,16 @@ class PostReceive
   include DedicatedSidekiqQueue
 
   def perform(repo_path, identifier, changes)
-    if repository_storage = Gitlab.config.repositories.storages.find { |p| repo_path.start_with?(p[1]['path'].to_s) }
-      repo_path.gsub!(repository_storage[1]['path'].to_s, "")
-    else
-      log("Check gitlab.yml config for correct repositories.storages values. No repository storage path matches \"#{repo_path}\"")
-    end
+    repo_relative_path = Gitlab::RepoPath.strip_storage_path(repo_path)
 
     changes = Base64.decode64(changes) unless changes.include?(' ')
     # Use Sidekiq.logger so arguments can be correlated with execution
     # time and thread ID's.
     Sidekiq.logger.info "changes: #{changes.inspect}" if ENV['SIDEKIQ_LOG_ARGUMENTS']
-    post_received = Gitlab::GitPostReceive.new(repo_path, identifier, changes)
+    post_received = Gitlab::GitPostReceive.new(repo_relative_path, identifier, changes)
 
     if post_received.project.nil?
-      log("Triggered hook for non-existing project with full path \"#{repo_path}\"")
+      log("Triggered hook for non-existing project with full path \"#{repo_relative_path}\"")
       return false
     end
 
@@ -25,7 +21,7 @@ class PostReceive
     elsif post_received.regular_project?
       process_project_changes(post_received)
     else
-      log("Triggered hook for unidentifiable repository type with full path \"#{repo_path}\"")
+      log("Triggered hook for unidentifiable repository type with full path \"#{repo_relative_path}\"")
       false
     end
   end

lib/gitlab/repo_path.rb

+module Gitlab
+  module RepoPath
+    NotFoundError = Class.new(StandardError)
+
+    def self.strip_storage_path(repo_path)
+      result = nil
+
+      Gitlab.config.repositories.storages.values.each do |params|
+        storage_path = params['path']
+        if repo_path.start_with?(storage_path)
+          result = repo_path.sub(storage_path, '')
+          break
+        end
+      end
+
+      if result.nil?
+        raise NotFoundError.new("No known storage path matches #{repo_path.inspect}")
+      end
+
+      result.sub(/\A\/*/, '')
+    end
+  end
+end

spec/lib/gitlab/repo_path_spec.rb

+require 'spec_helper'
+
+describe ::Gitlab::RepoPath do
+  describe '.strip_storage_path' do
+    before do
+      allow(Gitlab.config.repositories).to receive(:storages).and_return({
+        'storage1' => { 'path' => '/foo' },
+        'storage2' => { 'path' => '/bar' },
+      })
+    end
+
+    it 'strips the storage path' do
+      expect(described_class.strip_storage_path('/bar/foo/qux/baz.git')).to eq('foo/qux/baz.git')
+    end
+
+    it 'raises NotFoundError if no storage matches the path' do
+      expect { described_class.strip_storage_path('/doesnotexist/foo.git') }.to raise_error(
+        described_class::NotFoundError
+      )
+    end
+  end
+end