Allow git pull/push on project redirects

20 files changed, 510 insertions, 52 deletions

diff --git a/GITLAB_SHELL_VERSION b/GITLAB_SHELL_VERSION
index 4e32c7b1caf..269fb5dfe2c 100644
--- a/GITLAB_SHELL_VERSION
+++ b/GITLAB_SHELL_VERSION
@@ -1 +1 @@
-5.10.1
+5.10.2
diff --git a/app/models/namespace.rb b/app/models/namespace.rb
index 901dbf2ba69..0ff169d4531 100644
--- a/app/models/namespace.rb
+++ b/app/models/namespace.rb
@@ -40,6 +40,7 @@ class Namespace < ActiveRecord::Base
     namespace_path: true
 
   validate :nesting_level_allowed
+  validate :allowed_path_by_redirects
 
   delegate :name, to: :owner, allow_nil: true, prefix: true
 
@@ -257,4 +258,14 @@ class Namespace < ActiveRecord::Base
     Namespace.where(id: descendants.select(:id))
       .update_all(share_with_group_lock: true)
   end
+
+  def allowed_path_by_redirects
+    return if path.nil?
+
+    errors.add(:path, "#{path} has been taken before. Please use another one") if namespace_previously_created_with_same_path?
+  end
+
+  def namespace_previously_created_with_same_path?
+    RedirectRoute.permanent.exists?(path: path)
+  end
 end
diff --git a/app/models/redirect_route.rb b/app/models/redirect_route.rb
index 31de204d824..20532527346 100644
--- a/app/models/redirect_route.rb
+++ b/app/models/redirect_route.rb
@@ -17,4 +17,32 @@ class RedirectRoute < ActiveRecord::Base
 
     where(wheres, path, "#{sanitize_sql_like(path)}/%")
   end
+
+  scope :permanent, -> do
+    if column_permanent_exists?
+      where(permanent: true)
+    else
+      none
+    end
+  end
+
+  scope :temporary, -> do
+    if column_permanent_exists?
+      where(permanent: [false, nil])
+    else
+      all
+    end
+  end
+
+  default_value_for :permanent, false
+
+  def permanent=(value)
+    if self.class.column_permanent_exists?
+      super
+    end
+  end
+
+  def self.column_permanent_exists?
+    ActiveRecord::Base.connection.column_exists?(:redirect_routes, :permanent)
+  end
 end
diff --git a/app/models/route.rb b/app/models/route.rb
index 97e8a6ad9e9..7ba3ec06041 100644
--- a/app/models/route.rb
+++ b/app/models/route.rb
@@ -8,6 +8,8 @@ class Route < ActiveRecord::Base
     presence: true,
     uniqueness: { case_sensitive: false }
 
+  validate :ensure_permanent_paths
+
   after_create :delete_conflicting_redirects
   after_update :delete_conflicting_redirects, if: :path_changed?
   after_update :create_redirect_for_old_path
@@ -40,7 +42,7 @@ class Route < ActiveRecord::Base
         # We are not calling route.delete_conflicting_redirects here, in hopes
         # of avoiding deadlocks. The parent (self, in this method) already
         # called it, which deletes conflicts for all descendants.
-        route.create_redirect(old_path) if attributes[:path]
+        route.create_redirect(old_path, permanent: permanent_redirect?) if attributes[:path]
       end
     end
   end
@@ -50,16 +52,30 @@ class Route < ActiveRecord::Base
   end
 
   def conflicting_redirects
-    RedirectRoute.matching_path_and_descendants(path)
+    RedirectRoute.temporary.matching_path_and_descendants(path)
   end
 
-  def create_redirect(path)
-    RedirectRoute.create(source: source, path: path)
+  def create_redirect(path, permanent: false)
+    RedirectRoute.create(source: source, path: path, permanent: permanent)
   end
 
   private
 
   def create_redirect_for_old_path
-    create_redirect(path_was) if path_changed?
+    create_redirect(path_was, permanent: permanent_redirect?) if path_changed?
+  end
+
+  def permanent_redirect?
+    source_type != "Project"
+  end
+
+  def ensure_permanent_paths
+    return if path.nil?
+
+    errors.add(:path, "#{path} has been taken before. Please use another one") if conflicting_redirect_exists?
+  end
+
+  def conflicting_redirect_exists?
+    RedirectRoute.permanent.matching_path_and_descendants(path).exists?
   end
 end
diff --git a/changelogs/unreleased/35385-allow-git-pull-push-on-project-redirects.yml b/changelogs/unreleased/35385-allow-git-pull-push-on-project-redirects.yml
new file mode 100644
index 00000000000..31450287caf
--- /dev/null
+++ b/changelogs/unreleased/35385-allow-git-pull-push-on-project-redirects.yml
@@ -0,0 +1,5 @@
+---
+title: Allow git pull/push on group/user/project redirects
+merge_request: 15670
+author:
+type: added
diff --git a/db/migrate/20171204204233_add_permanent_to_redirect_route.rb b/db/migrate/20171204204233_add_permanent_to_redirect_route.rb
new file mode 100644
index 00000000000..f3ae471201e
--- /dev/null
+++ b/db/migrate/20171204204233_add_permanent_to_redirect_route.rb
@@ -0,0 +1,18 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddPermanentToRedirectRoute < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+  disable_ddl_transaction!
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  def up
+    add_column(:redirect_routes, :permanent, :boolean)
+  end
+
+  def down
+    remove_column(:redirect_routes, :permanent)
+  end
+end
diff --git a/db/migrate/20171206221519_add_permanent_index_to_redirect_route.rb b/db/migrate/20171206221519_add_permanent_index_to_redirect_route.rb
new file mode 100644
index 00000000000..33ce7e1aa68
--- /dev/null
+++ b/db/migrate/20171206221519_add_permanent_index_to_redirect_route.rb
@@ -0,0 +1,19 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddPermanentIndexToRedirectRoute < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index(:redirect_routes, :permanent)
+  end
+
+  def down
+    remove_concurrent_index(:redirect_routes, :permanent) if index_exists?(:redirect_routes, :permanent)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4c697a4a384..c0a141885ad 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20171205190711) do
+ActiveRecord::Schema.define(version: 20171206221519) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -1526,10 +1526,12 @@ ActiveRecord::Schema.define(version: 20171205190711) do
     t.string "path", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.boolean "permanent"
   end
 
   add_index "redirect_routes", ["path"], name: "index_redirect_routes_on_path", unique: true, using: :btree
   add_index "redirect_routes", ["path"], name: "index_redirect_routes_on_path_text_pattern_ops", using: :btree, opclasses: {"path"=>"varchar_pattern_ops"}
+  add_index "redirect_routes", ["permanent"], name: "index_redirect_routes_on_permanent", using: :btree
   add_index "redirect_routes", ["source_type", "source_id"], name: "index_redirect_routes_on_source_type_and_source_id", using: :btree
 
   create_table "releases", force: :cascade do |t|
diff --git a/lib/api/internal.rb b/lib/api/internal.rb
index 451121a4cea..ccaaeca10d4 100644
--- a/lib/api/internal.rb
+++ b/lib/api/internal.rb
@@ -4,6 +4,7 @@ module API
     before { authenticate_by_gitlab_shell_token! }
 
     helpers ::API::Helpers::InternalHelpers
+    helpers ::Gitlab::Identifier
 
     namespace 'internal' do
       # Check if git command is allowed to project
@@ -176,17 +177,25 @@ module API
 
       post '/post_receive' do
         status 200
-
         PostReceive.perform_async(params[:gl_repository], params[:identifier],
           params[:changes])
         broadcast_message = BroadcastMessage.current&.last&.message
         reference_counter_decreased = Gitlab::ReferenceCounter.new(params[:gl_repository]).decrease
 
-        {
+        output = {
           merge_request_urls: merge_request_urls,
           broadcast_message: broadcast_message,
           reference_counter_decreased: reference_counter_decreased
         }
+
+        project = Gitlab::GlRepository.parse(params[:gl_repository]).first
+        user = identify(params[:identifier])
+        redirect_message = Gitlab::Checks::ProjectMoved.fetch_redirect_message(user.id, project.id)
+        if redirect_message
+          output[:redirected_message] = redirect_message
+        end
+
+        output
       end
     end
   end
diff --git a/lib/gitlab/checks/project_moved.rb b/lib/gitlab/checks/project_moved.rb
new file mode 100644
index 00000000000..3a1c0a3455e
--- /dev/null
+++ b/lib/gitlab/checks/project_moved.rb
@@ -0,0 +1,65 @@
+module Gitlab
+  module Checks
+    class ProjectMoved
+      REDIRECT_NAMESPACE = "redirect_namespace".freeze
+
+      def initialize(project, user, redirected_path, protocol)
+        @project = project
+        @user = user
+        @redirected_path = redirected_path
+        @protocol = protocol
+      end
+
+      def self.fetch_redirect_message(user_id, project_id)
+        redirect_key = redirect_message_key(user_id, project_id)
+
+        Gitlab::Redis::SharedState.with do |redis|
+          message = redis.get(redirect_key)
+          redis.del(redirect_key)
+          message
+        end
+      end
+
+      def add_redirect_message
+        Gitlab::Redis::SharedState.with do |redis|
+          key = self.class.redirect_message_key(user.id, project.id)
+          redis.setex(key, 5.minutes, redirect_message)
+        end
+      end
+
+      def redirect_message(rejected: false)
+        <<~MESSAGE.strip_heredoc
+        Project '#{redirected_path}' was moved to '#{project.full_path}'.
+
+        Please update your Git remote:
+
+          #{remote_url_message(rejected)}
+        MESSAGE
+      end
+
+      def permanent_redirect?
+        RedirectRoute.permanent.exists?(path: redirected_path)
+      end
+
+      private
+
+      attr_reader :project, :redirected_path, :protocol, :user
+
+      def self.redirect_message_key(user_id, project_id)
+        "#{REDIRECT_NAMESPACE}:#{user_id}:#{project_id}"
+      end
+
+      def remote_url_message(rejected)
+        if rejected
+          "git remote set-url origin #{url} and try again."
+        else
+          "git remote set-url origin #{url}"
+        end
+      end
+
+      def url
+        protocol == 'ssh' ? project.ssh_url_to_repo : project.http_url_to_repo
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/git_access.rb b/lib/gitlab/git_access.rb
index 9d7d921bb9c..56f6febe86d 100644
--- a/lib/gitlab/git_access.rb
+++ b/lib/gitlab/git_access.rb
@@ -102,18 +102,15 @@ module Gitlab
     end
 
     def check_project_moved!
-      return unless redirected_path
+      return if redirected_path.nil?
 
-      url = protocol == 'ssh' ? project.ssh_url_to_repo : project.http_url_to_repo
-      message = <<-MESSAGE.strip_heredoc
-        Project '#{redirected_path}' was moved to '#{project.full_path}'.
+      project_moved = Checks::ProjectMoved.new(project, user, redirected_path, protocol)
 
-        Please update your Git remote and try again:
-
-          git remote set-url origin #{url}
-      MESSAGE
-
-      raise ProjectMovedError, message
+      if project_moved.permanent_redirect?
+        project_moved.add_redirect_message
+      else
+        raise ProjectMovedError, project_moved.redirect_message(rejected: true)
+      end
     end
 
     def check_command_disabled!(cmd)
diff --git a/lib/gitlab/identifier.rb b/lib/gitlab/identifier.rb
index 94678b6ec40..3f3f10596c5 100644
--- a/lib/gitlab/identifier.rb
+++ b/lib/gitlab/identifier.rb
@@ -2,9 +2,8 @@
 # key-13 or user-36 or last commit
 module Gitlab
   module Identifier
-    def identify(identifier, project, newrev)
+    def identify(identifier, project = nil, newrev = nil)
       if identifier.blank?
-        # Local push from gitlab
         identify_using_commit(project, newrev)
       elsif identifier =~ /\Auser-\d+\Z/
         # git push over http
@@ -17,6 +16,8 @@ module Gitlab
 
     # Tries to identify a user based on a commit SHA.
     def identify_using_commit(project, ref)
+      return if project.nil? && ref.nil?
+
       commit = project.commit(ref)
 
       return if !commit || !commit.author_email
diff --git a/spec/lib/gitlab/checks/project_moved_spec.rb b/spec/lib/gitlab/checks/project_moved_spec.rb
new file mode 100644
index 00000000000..fa1575e2177
--- /dev/null
+++ b/spec/lib/gitlab/checks/project_moved_spec.rb
@@ -0,0 +1,81 @@
+require 'rails_helper'
+
+describe Gitlab::Checks::ProjectMoved, :clean_gitlab_redis_shared_state do
+  let(:user) { create(:user) }
+  let(:project) { create(:project) }
+
+  describe '.fetch_redirct_message' do
+    context 'with a redirect message queue' do
+      it 'should return the redirect message' do
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        project_moved.add_redirect_message
+
+        expect(described_class.fetch_redirect_message(user.id, project.id)).to eq(project_moved.redirect_message)
+      end
+
+      it 'should delete the redirect message from redis' do
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        project_moved.add_redirect_message
+
+        expect(Gitlab::Redis::SharedState.with { |redis| redis.get("redirect_namespace:#{user.id}:#{project.id}") }).not_to be_nil
+        described_class.fetch_redirect_message(user.id, project.id)
+        expect(Gitlab::Redis::SharedState.with { |redis| redis.get("redirect_namespace:#{user.id}:#{project.id}") }).to be_nil
+      end
+    end
+
+    context 'with no redirect message queue' do
+      it 'should return nil' do
+        expect(described_class.fetch_redirect_message(1, 2)).to be_nil
+      end
+    end
+  end
+
+  describe '#add_redirect_message' do
+    it 'should queue a redirect message' do
+      project_moved = described_class.new(project, user, 'foo/bar', 'http')
+      expect(project_moved.add_redirect_message).to eq("OK")
+    end
+  end
+
+  describe '#redirect_message' do
+    context 'when the push is rejected' do
+      it 'should return a redirect message telling the user to try again' do
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        message = "Project 'foo/bar' was moved to '#{project.full_path}'." +
+          "\n\nPlease update your Git remote:" +
+          "\n\n  git remote set-url origin #{project.http_url_to_repo} and try again.\n"
+
+        expect(project_moved.redirect_message(rejected: true)).to eq(message)
+      end
+    end
+
+    context 'when the push is not rejected' do
+      it 'should return a redirect message' do
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        message = "Project 'foo/bar' was moved to '#{project.full_path}'." +
+          "\n\nPlease update your Git remote:" +
+          "\n\n  git remote set-url origin #{project.http_url_to_repo}\n"
+
+        expect(project_moved.redirect_message).to eq(message)
+      end
+    end
+  end
+
+  describe '#permanent_redirect?' do
+    context 'with a permanent RedirectRoute' do
+      it 'should return true' do
+        project.route.create_redirect('foo/bar', permanent: true)
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        expect(project_moved.permanent_redirect?).to be_truthy
+      end
+    end
+
+    context 'without a permanent RedirectRoute' do
+      it 'should return false' do
+        project.route.create_redirect('foo/bar')
+        project_moved = described_class.new(project, user, 'foo/bar', 'http')
+        expect(project_moved.permanent_redirect?).to be_falsy
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/git_access_spec.rb b/spec/lib/gitlab/git_access_spec.rb
index c9643c5da47..2db560c2cec 100644
--- a/spec/lib/gitlab/git_access_spec.rb
+++ b/spec/lib/gitlab/git_access_spec.rb
@@ -193,7 +193,15 @@ describe Gitlab::GitAccess do
     let(:actor) { build(:rsa_deploy_key_2048, user: user) }
   end
 
-  describe '#check_project_moved!' do
+  shared_examples 'check_project_moved' do
+    it 'enqueues a redirected message' do
+      push_access_check
+
+      expect(Gitlab::Checks::ProjectMoved.fetch_redirect_message(user.id, project.id)).not_to be_nil
+    end
+  end
+
+  describe '#check_project_moved!', :clean_gitlab_redis_shared_state do
     before do
       project.add_master(user)
     end
@@ -207,7 +215,40 @@ describe Gitlab::GitAccess do
       end
     end
 
-    context 'when a redirect was followed to find the project' do
+    context 'when a permanent redirect and ssh protocol' do
+      let(:redirected_path) { 'some/other-path' }
+
+      before do
+        allow_any_instance_of(Gitlab::Checks::ProjectMoved).to receive(:permanent_redirect?).and_return(true)
+      end
+
+      it 'allows push and pull access' do
+        aggregate_failures do
+          expect { push_access_check }.not_to raise_error
+        end
+      end
+
+      it_behaves_like 'check_project_moved'
+    end
+
+    context 'with a permanent redirect and http protocol' do
+      let(:redirected_path) { 'some/other-path' }
+      let(:protocol) { 'http' }
+
+      before do
+        allow_any_instance_of(Gitlab::Checks::ProjectMoved).to receive(:permanent_redirect?).and_return(true)
+      end
+
+      it 'allows_push and pull access' do
+        aggregate_failures do
+          expect { push_access_check }.not_to raise_error
+        end
+      end
+
+      it_behaves_like 'check_project_moved'
+    end
+
+    context 'with a temporal redirect and ssh protocol' do
       let(:redirected_path) { 'some/other-path' }
 
       it 'blocks push and pull access' do
@@ -219,16 +260,15 @@ describe Gitlab::GitAccess do
           expect { pull_access_check }.to raise_error(described_class::ProjectMovedError, /git remote set-url origin #{project.ssh_url_to_repo}/)
         end
       end
+    end
 
-      context 'http protocol' do
-        let(:protocol) { 'http' }
+    context 'with a temporal redirect and http protocol' do
+      let(:redirected_path) { 'some/other-path' }
+      let(:protocol) { 'http' }
 
-        it 'includes the path to the project using HTTP' do
-          aggregate_failures do
-            expect { push_access_check }.to raise_error(described_class::ProjectMovedError, /git remote set-url origin #{project.http_url_to_repo}/)
-            expect { pull_access_check }.to raise_error(described_class::ProjectMovedError, /git remote set-url origin #{project.http_url_to_repo}/)
-          end
-        end
+      it 'does not allow to push and pull access' do
+        expect { push_access_check }.to raise_error(described_class::ProjectMovedError, /git remote set-url origin #{project.http_url_to_repo}/)
+        expect { pull_access_check }.to raise_error(described_class::ProjectMovedError, /git remote set-url origin #{project.http_url_to_repo}/)
       end
     end
   end
diff --git a/spec/lib/gitlab/identifier_spec.rb b/spec/lib/gitlab/identifier_spec.rb
index cfaeb1f0d4f..0385dd762c2 100644
--- a/spec/lib/gitlab/identifier_spec.rb
+++ b/spec/lib/gitlab/identifier_spec.rb
@@ -70,6 +70,10 @@ describe Gitlab::Identifier do
         expect(identifier.identify_using_commit(project, '123')).to eq(user)
       end
     end
+
+    it 'returns nil if the project & ref are not present' do
+      expect(identifier.identify_using_commit(nil, nil)).to be_nil
+    end
   end
 
   describe '#identify_using_user' do
diff --git a/spec/models/namespace_spec.rb b/spec/models/namespace_spec.rb
index 3817f20bfe7..b7c6286fd83 100644
--- a/spec/models/namespace_spec.rb
+++ b/spec/models/namespace_spec.rb
@@ -559,4 +559,34 @@ describe Namespace do
       end
     end
   end
+
+  describe "#allowed_path_by_redirects" do
+    let(:namespace1) { create(:namespace, path: 'foo') }
+
+    context "when the path has been taken before" do
+      before do
+        namespace1.path = 'bar'
+        namespace1.save!
+      end
+
+      it 'should be invalid' do
+        namespace2 = build(:group, path: 'foo')
+        expect(namespace2).to be_invalid
+      end
+
+      it 'should return an error on path' do
+        namespace2 = build(:group, path: 'foo')
+        namespace2.valid?
+        expect(namespace2.errors.messages[:path].first).to eq('foo has been taken before. Please use another one')
+      end
+    end
+
+    context "when the path has not been taken before" do
+      it 'should be valid' do
+        expect(RedirectRoute.count).to eq(0)
+        namespace = build(:namespace)
+        expect(namespace).to be_valid
+      end
+    end
+  end
 end
diff --git a/spec/models/route_spec.rb b/spec/models/route_spec.rb
index fece370c03f..ddad6862a63 100644
--- a/spec/models/route_spec.rb
+++ b/spec/models/route_spec.rb
@@ -87,6 +87,7 @@ describe Route do
       end
 
       context 'when conflicting redirects exist' do
+        let(:route) { create(:project).route }
         let!(:conflicting_redirect1) { route.create_redirect('bar/test') }
         let!(:conflicting_redirect2) { route.create_redirect('bar/test/foo') }
         let!(:conflicting_redirect3) { route.create_redirect('gitlab-org') }
@@ -141,11 +142,50 @@ describe Route do
       expect(redirect_route.source).to eq(route.source)
       expect(redirect_route.path).to eq('foo')
     end
+
+    context 'when the source is a Project' do
+      it 'creates a temporal RedirectRoute' do
+        project = create(:project)
+        route = project.route
+        redirect_route = route.create_redirect('foo')
+        expect(redirect_route.permanent?).to be_falsy
+      end
+    end
+
+    context 'when the source is not a project' do
+      it 'creates a permanent RedirectRoute' do
+        redirect_route = route.create_redirect('foo', permanent: true)
+        expect(redirect_route.permanent?).to be_truthy
+      end
+    end
   end
 
   describe '#delete_conflicting_redirects' do
+    context 'with permanent redirect' do
+      it 'does not delete the redirect' do
+        route.create_redirect("#{route.path}/foo", permanent: true)
+
+        expect do
+          route.delete_conflicting_redirects
+        end.not_to change { RedirectRoute.count }
+      end
+    end
+
+    context 'with temporal redirect' do
+      let(:route) { create(:project).route }
+
+      it 'deletes the redirect' do
+        route.create_redirect("#{route.path}/foo")
+
+        expect do
+          route.delete_conflicting_redirects
+        end.to change { RedirectRoute.count }.by(-1)
+      end
+    end
+
     context 'when a redirect route with the same path exists' do
       context 'when the redirect route has matching case' do
+        let(:route) { create(:project).route }
         let!(:redirect1) { route.create_redirect(route.path) }
 
         it 'deletes the redirect' do
@@ -169,6 +209,7 @@ describe Route do
       end
 
       context 'when the redirect route is differently cased' do
+        let(:route) { create(:project).route }
         let!(:redirect1) { route.create_redirect(route.path.upcase) }
 
         it 'deletes the redirect' do
@@ -185,7 +226,32 @@ describe Route do
       expect(route.conflicting_redirects).to be_an(ActiveRecord::Relation)
     end
 
+    context 'with permanent redirects' do
+      it 'does not return anything' do
+        route.create_redirect("#{route.path}/foo", permanent: true)
+        route.create_redirect("#{route.path}/foo/bar", permanent: true)
+        route.create_redirect("#{route.path}/baz/quz", permanent: true)
+
+        expect(route.conflicting_redirects).to be_empty
+      end
+    end
+
+    context 'with temporal redirects' do
+      let(:route) { create(:project).route }
+
+      it 'returns the redirect routes' do
+        route = create(:project).route
+        redirect1 = route.create_redirect("#{route.path}/foo")
+        redirect2 = route.create_redirect("#{route.path}/foo/bar")
+        redirect3 = route.create_redirect("#{route.path}/baz/quz")
+
+        expect(route.conflicting_redirects).to match_array([redirect1, redirect2, redirect3])
+      end
+    end
+
     context 'when a redirect route with the same path exists' do
+      let(:route) { create(:project).route }
+
       context 'when the redirect route has matching case' do
         let!(:redirect1) { route.create_redirect(route.path) }
 
@@ -214,4 +280,42 @@ describe Route do
       end
     end
   end
+
+  describe "#conflicting_redirect_exists?" do
+    context 'when a conflicting redirect exists' do
+      let(:group1) { create(:group, path: 'foo') }
+      let(:group2) { create(:group, path: 'baz') }
+
+      it 'should not be saved' do
+        group1.path = 'bar'
+        group1.save
+
+        group2.path = 'foo'
+
+        expect(group2.save).to be_falsy
+      end
+
+      it 'should return an error on path' do
+        group1.path = 'bar'
+        group1.save
+
+        group2.path = 'foo'
+        group2.valid?
+        expect(group2.errors["route.path"].first).to eq('foo has been taken before. Please use another one')
+      end
+    end
+
+    context 'when a conflicting redirect does not exist' do
+      let(:project1) { create(:project, path: 'foo') }
+      let(:project2) { create(:project, path: 'baz') }
+
+      it 'should be saved' do
+        project1.path = 'bar'
+        project1.save
+
+        project2.path = 'foo'
+        expect(project2.save).to be_truthy
+      end
+    end
+  end
 end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 03c96a8f5aa..cdabd35b6ba 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -2592,4 +2592,28 @@ describe User do
       include_examples 'max member access for groups'
     end
   end
+
+  describe "#username_previously_taken?" do
+    let(:user1) { create(:user, username: 'foo') }
+
+    context 'when the username has been taken before' do
+      before do
+        user1.username = 'bar'
+        user1.save!
+      end
+
+      it 'should raise an ActiveRecord::RecordInvalid exception' do
+        user2 = build(:user, username: 'foo')
+        expect { user2.save! }.to raise_error(ActiveRecord::RecordInvalid, /Path foo has been taken before/)
+      end
+    end
+
+    context 'when the username has not been taken before' do
+      it 'should be valid' do
+        expect(RedirectRoute.count).to eq(0)
+        user2 = build(:user, username: 'baz')
+        expect(user2).to be_valid
+      end
+    end
+  end
 end
diff --git a/spec/requests/api/internal_spec.rb b/spec/requests/api/internal_spec.rb
index 67e1539cbc3..3c31980b273 100644
--- a/spec/requests/api/internal_spec.rb
+++ b/spec/requests/api/internal_spec.rb
@@ -537,16 +537,7 @@ describe API::Internal do
 
     context 'the project path was changed' do
       let!(:old_path_to_repo) { project.repository.path_to_repo }
-      let!(:old_full_path) { project.full_path }
-      let(:project_moved_message) do
-        <<-MSG.strip_heredoc
-          Project '#{old_full_path}' was moved to '#{project.full_path}'.
-
-          Please update your Git remote and try again:
-
-            git remote set-url origin #{project.ssh_url_to_repo}
-        MSG
-      end
+      let!(:repository) { project.repository }
 
       before do
         project.team << [user, :developer]
@@ -555,19 +546,17 @@ describe API::Internal do
       end
 
       it 'rejects the push' do
-        push_with_path(key, old_path_to_repo)
+        push(key, project)
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response['status']).to be_falsey
-        expect(json_response['message']).to eq(project_moved_message)
+        expect(json_response['status']).to be_falsy
       end
 
       it 'rejects the SSH pull' do
-        pull_with_path(key, old_path_to_repo)
+        pull(key, project)
 
         expect(response).to have_gitlab_http_status(200)
-        expect(json_response['status']).to be_falsey
-        expect(json_response['message']).to eq(project_moved_message)
+        expect(json_response['status']).to be_falsy
       end
     end
   end
@@ -695,7 +684,7 @@ describe API::Internal do
   #   end
   # end
 
-  describe 'POST /internal/post_receive' do
+  describe 'POST /internal/post_receive', :clean_gitlab_redis_shared_state do
     let(:identifier) { 'key-123' }
 
     let(:valid_params) do
@@ -713,6 +702,8 @@ describe API::Internal do
 
     before do
       project.team << [user, :developer]
+      allow(described_class).to receive(:identify).and_return(user)
+      allow_any_instance_of(Gitlab::Identifier).to receive(:identify).and_return(user)
     end
 
     it 'enqueues a PostReceive worker job' do
@@ -780,6 +771,19 @@ describe API::Internal do
         expect(json_response['broadcast_message']).to eq(nil)
       end
     end
+
+    context 'with a redirected data' do
+      it 'returns redirected message on the response' do
+        project_moved = Gitlab::Checks::ProjectMoved.new(project, user, 'foo/baz', 'http')
+        project_moved.add_redirect_message
+
+        post api("/internal/post_receive"), valid_params
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(json_response["redirected_message"]).to be_present
+        expect(json_response["redirected_message"]).to eq(project_moved.redirect_message)
+      end
+    end
   end
 
   describe 'POST /internal/pre_receive' do
diff --git a/spec/requests/git_http_spec.rb b/spec/requests/git_http_spec.rb
index a16f98bec36..fa02fffc82a 100644
--- a/spec/requests/git_http_spec.rb
+++ b/spec/requests/git_http_spec.rb
@@ -324,9 +324,9 @@ describe 'Git HTTP requests' do
             <<-MSG.strip_heredoc
               Project '#{redirect.path}' was moved to '#{project.full_path}'.
 
-              Please update your Git remote and try again:
+              Please update your Git remote:
 
-                git remote set-url origin #{project.http_url_to_repo}
+                git remote set-url origin #{project.http_url_to_repo} and try again.
             MSG
           end
 
@@ -533,9 +533,9 @@ describe 'Git HTTP requests' do
                   <<-MSG.strip_heredoc
                     Project '#{redirect.path}' was moved to '#{project.full_path}'.
 
-                    Please update your Git remote and try again:
+                    Please update your Git remote:
 
-                      git remote set-url origin #{project.http_url_to_repo}
+                      git remote set-url origin #{project.http_url_to_repo} and try again.
                   MSG
                 end