Create idea of read-only databasetc-geo-read-only-idea

In GitLab EE, a GitLab instance can be read-only (e.g. when it's a Geo
secondary node). But in GitLab CE it also might be useful to have the
"read-only" idea around. So port it back to GitLab CE.

Also having the principle of read-only in GitLab CE would hopefully
lead to less errors introduced, doing write operations when there
aren't allowed for read-only calls.

Closes gitlab-org/gitlab-ce#37534.

12 files changed, 329 insertions, 50 deletions

diff --git a/spec/factories/projects.rb b/spec/factories/projects.rb
index 958d62181a2..4034e7905ad 100644
--- a/spec/factories/projects.rb
+++ b/spec/factories/projects.rb
@@ -149,7 +149,7 @@ FactoryGirl.define do
       end
     end
 
-    trait :readonly do
+    trait :read_only do
       repository_read_only true
     end
 
diff --git a/spec/lib/banzai/renderer_spec.rb b/spec/lib/banzai/renderer_spec.rb
index da42272bbef..81a04a2d46d 100644
--- a/spec/lib/banzai/renderer_spec.rb
+++ b/spec/lib/banzai/renderer_spec.rb
@@ -31,7 +31,14 @@ describe Banzai::Renderer do
         let(:object) { fake_object(fresh: false) }
 
         it 'caches and returns the result' do
-          expect(object).to receive(:refresh_markdown_cache!).with(do_update: true)
+          expect(object).to receive(:refresh_markdown_cache!)
+
+          is_expected.to eq('field_html')
+        end
+
+        it "skips database caching on a GitLab read-only instance" do
+          allow(Gitlab::Database).to receive(:read_only?).and_return(true)
+          expect(object).to receive(:refresh_markdown_cache!)
 
           is_expected.to eq('field_html')
         end
diff --git a/spec/lib/gitlab/git_access_spec.rb b/spec/lib/gitlab/git_access_spec.rb
index 458627ee4de..c54327bd2e4 100644
--- a/spec/lib/gitlab/git_access_spec.rb
+++ b/spec/lib/gitlab/git_access_spec.rb
@@ -598,6 +598,19 @@ describe Gitlab::GitAccess do
                                                             admin: { push_protected_branch: false, push_all: false, merge_into_protected_branch: false }))
       end
     end
+
+    context "when in a read-only GitLab instance" do
+      before do
+        create(:protected_branch, name: 'feature', project: project)
+        allow(Gitlab::Database).to receive(:read_only?) { true }
+      end
+
+      # Only check admin; if an admin can't do it, other roles can't either
+      matrix = permissions_matrix[:admin].dup
+      matrix.each { |key, _| matrix[key] = false }
+
+      run_permission_checks(admin: matrix)
+    end
   end
 
   describe 'build authentication abilities' do
@@ -632,6 +645,16 @@ describe Gitlab::GitAccess do
     end
   end
 
+  context 'when the repository is read only' do
+    let(:project) { create(:project, :repository, :read_only) }
+
+    it 'denies push access' do
+      project.add_master(user)
+
+      expect { push_access_check }.to raise_unauthorized('The repository is temporarily read-only. Please try again later.')
+    end
+  end
+
   describe 'deploy key permissions' do
     let(:key) { create(:deploy_key, user: user, can_push: can_push) }
     let(:actor) { key }
diff --git a/spec/lib/gitlab/git_access_wiki_spec.rb b/spec/lib/gitlab/git_access_wiki_spec.rb
index 0376b4ee783..1056074264a 100644
--- a/spec/lib/gitlab/git_access_wiki_spec.rb
+++ b/spec/lib/gitlab/git_access_wiki_spec.rb
@@ -4,6 +4,7 @@ describe Gitlab::GitAccessWiki do
   let(:access) { described_class.new(user, project, 'web', authentication_abilities: authentication_abilities, redirected_path: redirected_path) }
   let(:project) { create(:project, :repository) }
   let(:user) { create(:user) }
+  let(:changes) { ['6f6d7e7ed 570e7b2ab refs/heads/master'] }
   let(:redirected_path) { nil }
   let(:authentication_abilities) do
     [
@@ -13,19 +14,27 @@ describe Gitlab::GitAccessWiki do
     ]
   end
 
-  describe 'push_allowed?' do
-    before do
-      create(:protected_branch, name: 'master', project: project)
-      project.team << [user, :developer]
-    end
+  describe '#push_access_check' do
+    context 'when user can :create_wiki' do
+      before do
+        create(:protected_branch, name: 'master', project: project)
+        project.team << [user, :developer]
+      end
 
-    subject { access.check('git-receive-pack', changes) }
+      subject { access.check('git-receive-pack', changes) }
 
-    it { expect { subject }.not_to raise_error }
-  end
+      it { expect { subject }.not_to raise_error }
+
+      context 'when in a read-only GitLab instance' do
+        before do
+          allow(Gitlab::Database).to receive(:read_only?) { true }
+        end
 
-  def changes
-    ['6f6d7e7ed 570e7b2ab refs/heads/master']
+        it 'does not give access to upload wiki code' do
+          expect { subject }.to raise_error(Gitlab::GitAccess::UnauthorizedError, "You can't push code to a read-only GitLab instance.")
+        end
+      end
+    end
   end
 
   describe '#access_check_download!' do
diff --git a/spec/lib/gitlab/middleware/read_only_spec.rb b/spec/lib/gitlab/middleware/read_only_spec.rb
new file mode 100644
index 00000000000..742a792a1af
--- /dev/null
+++ b/spec/lib/gitlab/middleware/read_only_spec.rb
@@ -0,0 +1,142 @@
+require 'spec_helper'
+
+describe Gitlab::Middleware::ReadOnly do
+  include Rack::Test::Methods
+
+  RSpec::Matchers.define :be_a_redirect do
+    match do |response|
+      response.status == 301
+    end
+  end
+
+  RSpec::Matchers.define :disallow_request do
+    match do |middleware|
+      flash = middleware.send(:rack_flash)
+      flash['alert'] && flash['alert'].include?('You cannot do writing operations')
+    end
+  end
+
+  RSpec::Matchers.define :disallow_request_in_json do
+    match do |response|
+      json_response = JSON.parse(response.body)
+      response.body.include?('You cannot do writing operations') && json_response.key?('message')
+    end
+  end
+
+  let(:rack_stack) do
+    rack = Rack::Builder.new do
+      use ActionDispatch::Session::CacheStore
+      use ActionDispatch::Flash
+      use ActionDispatch::ParamsParser
+    end
+
+    rack.run(subject)
+    rack.to_app
+  end
+
+  subject { described_class.new(fake_app) }
+
+  let(:request) { Rack::MockRequest.new(rack_stack) }
+
+  context 'normal requests to a read-only Gitlab instance' do
+    let(:fake_app) { lambda { |env| [200, { 'Content-Type' => 'text/plain' }, ['OK']] } }
+
+    before do
+      allow(Gitlab::Database).to receive(:read_only?) { true }
+    end
+
+    it 'expects PATCH requests to be disallowed' do
+      response = request.patch('/test_request')
+
+      expect(response).to be_a_redirect
+      expect(subject).to disallow_request
+    end
+
+    it 'expects PUT requests to be disallowed' do
+      response = request.put('/test_request')
+
+      expect(response).to be_a_redirect
+      expect(subject).to disallow_request
+    end
+
+    it 'expects POST requests to be disallowed' do
+      response = request.post('/test_request')
+
+      expect(response).to be_a_redirect
+      expect(subject).to disallow_request
+    end
+
+    it 'expects a internal POST request to be allowed after a disallowed request' do
+      response = request.post('/test_request')
+
+      expect(response).to be_a_redirect
+
+      response = request.post("/api/#{API::API.version}/internal")
+
+      expect(response).not_to be_a_redirect
+    end
+
+    it 'expects DELETE requests to be disallowed' do
+      response = request.delete('/test_request')
+
+      expect(response).to be_a_redirect
+      expect(subject).to disallow_request
+    end
+
+    context 'whitelisted requests' do
+      it 'expects DELETE request to logout to be allowed' do
+        response = request.delete('/users/sign_out')
+
+        expect(response).not_to be_a_redirect
+        expect(subject).not_to disallow_request
+      end
+
+      it 'expects a POST internal request to be allowed' do
+        response = request.post("/api/#{API::API.version}/internal")
+
+        expect(response).not_to be_a_redirect
+        expect(subject).not_to disallow_request
+      end
+
+      it 'expects a POST LFS request to batch URL to be allowed' do
+        response = request.post('/root/rouge.git/info/lfs/objects/batch')
+
+        expect(response).not_to be_a_redirect
+        expect(subject).not_to disallow_request
+      end
+    end
+  end
+
+  context 'json requests to a read-only GitLab instance' do
+    let(:fake_app) { lambda { |env| [200, { 'Content-Type' => 'application/json' }, ['OK']] } }
+    let(:content_json) { { 'CONTENT_TYPE' => 'application/json' } }
+
+    before do
+      allow(Gitlab::Database).to receive(:read_only?) { true }
+    end
+
+    it 'expects PATCH requests to be disallowed' do
+      response = request.patch('/test_request', content_json)
+
+      expect(response).to disallow_request_in_json
+    end
+
+    it 'expects PUT requests to be disallowed' do
+      response = request.put('/test_request', content_json)
+
+      expect(response).to disallow_request_in_json
+    end
+
+    it 'expects POST requests to be disallowed' do
+      response = request.post('/test_request', content_json)
+
+      expect(response).to disallow_request_in_json
+    end
+
+    it 'expects DELETE requests to be disallowed' do
+      response = request.delete('/test_request', content_json)
+
+      expect(response).to disallow_request_in_json
+    end
+  end
+end
diff --git a/spec/lib/system_check/app/git_user_default_ssh_config_check_spec.rb b/spec/lib/system_check/app/git_user_default_ssh_config_check_spec.rb
index a0fb86345f3..b4b83b70d1c 100644
--- a/spec/lib/system_check/app/git_user_default_ssh_config_check_spec.rb
+++ b/spec/lib/system_check/app/git_user_default_ssh_config_check_spec.rb
@@ -39,6 +39,14 @@ describe SystemCheck::App::GitUserDefaultSSHConfigCheck do
 
       it { is_expected.to eq(expected_result) }
     end
+
+    it 'skips GitLab read-only instances' do
+      stub_user
+      stub_home_dir
+      allow(Gitlab::Database).to receive(:read_only?).and_return(true)
+
+      is_expected.to be_truthy
+    end
   end
 
   describe '#check?' do
diff --git a/spec/models/concerns/cache_markdown_field_spec.rb b/spec/models/concerns/cache_markdown_field_spec.rb
index 40bbb10eaac..129dfa07f15 100644
--- a/spec/models/concerns/cache_markdown_field_spec.rb
+++ b/spec/models/concerns/cache_markdown_field_spec.rb
@@ -178,57 +178,59 @@ describe CacheMarkdownField do
     end
   end
 
-  describe '#refresh_markdown_cache!' do
+  describe '#refresh_markdown_cache' do
     before do
       thing.foo = updated_markdown
     end
 
-    context 'do_update: false' do
-      it 'fills all html fields' do
-        thing.refresh_markdown_cache!
+    it 'fills all html fields' do
+      thing.refresh_markdown_cache
 
-        expect(thing.foo_html).to eq(updated_html)
-        expect(thing.foo_html_changed?).to be_truthy
-        expect(thing.baz_html_changed?).to be_truthy
-      end
+      expect(thing.foo_html).to eq(updated_html)
+      expect(thing.foo_html_changed?).to be_truthy
+      expect(thing.baz_html_changed?).to be_truthy
+    end
 
-      it 'does not save the result' do
-        expect(thing).not_to receive(:update_columns)
+    it 'does not save the result' do
+      expect(thing).not_to receive(:update_columns)
 
-        thing.refresh_markdown_cache!
-      end
+      thing.refresh_markdown_cache
+    end
 
-      it 'updates the markdown cache version' do
-        thing.cached_markdown_version = nil
-        thing.refresh_markdown_cache!
+    it 'updates the markdown cache version' do
+      thing.cached_markdown_version = nil
+      thing.refresh_markdown_cache
 
-        expect(thing.cached_markdown_version).to eq(CacheMarkdownField::CACHE_VERSION)
-      end
+      expect(thing.cached_markdown_version).to eq(CacheMarkdownField::CACHE_VERSION)
     end
+  end
 
-    context 'do_update: true' do
-      it 'fills all html fields' do
-        thing.refresh_markdown_cache!(do_update: true)
+  describe '#refresh_markdown_cache!' do
+    before do
+      thing.foo = updated_markdown
+    end
 
-        expect(thing.foo_html).to eq(updated_html)
-        expect(thing.foo_html_changed?).to be_truthy
-        expect(thing.baz_html_changed?).to be_truthy
-      end
+    it 'fills all html fields' do
+      thing.refresh_markdown_cache!
 
-      it 'skips saving if not persisted' do
-        expect(thing).to receive(:persisted?).and_return(false)
-        expect(thing).not_to receive(:update_columns)
+      expect(thing.foo_html).to eq(updated_html)
+      expect(thing.foo_html_changed?).to be_truthy
+      expect(thing.baz_html_changed?).to be_truthy
+    end
 
-        thing.refresh_markdown_cache!(do_update: true)
-      end
+    it 'skips saving if not persisted' do
+      expect(thing).to receive(:persisted?).and_return(false)
+      expect(thing).not_to receive(:update_columns)
 
-      it 'saves the changes using #update_columns' do
-        expect(thing).to receive(:persisted?).and_return(true)
-        expect(thing).to receive(:update_columns)
-          .with("foo_html" => updated_html, "baz_html" => "", "cached_markdown_version" => CacheMarkdownField::CACHE_VERSION)
+      thing.refresh_markdown_cache!
+    end
 
-        thing.refresh_markdown_cache!(do_update: true)
-      end
+    it 'saves the changes using #update_columns' do
+      expect(thing).to receive(:persisted?).and_return(true)
+      expect(thing).to receive(:update_columns)
+        .with("foo_html" => updated_html, "baz_html" => "", "cached_markdown_version" => CacheMarkdownField::CACHE_VERSION)
+
+      thing.refresh_markdown_cache!
     end
   end
 
diff --git a/spec/models/concerns/routable_spec.rb b/spec/models/concerns/routable_spec.rb
index b463d12e448..ab8773b7ede 100644
--- a/spec/models/concerns/routable_spec.rb
+++ b/spec/models/concerns/routable_spec.rb
@@ -12,6 +12,16 @@ describe Group, 'Routable' do
     it { is_expected.to have_many(:redirect_routes).dependent(:destroy) }
   end
 
+  describe 'GitLab read-only instance' do
+    it 'does not save route if route is not present' do
+      group.route.path = ''
+      allow(Gitlab::Database).to receive(:read_only?).and_return(true)
+      expect(group).to receive(:update_route).and_call_original
+
+      expect { group.full_path }.to change { Route.count }.by(0)
+    end
+  end
+
   describe 'Callbacks' do
     it 'creates route record on create' do
       expect(group.route.path).to eq(group.path)
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index 9b470e79a76..ec700215521 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -692,6 +692,44 @@ describe Project do
         project.cache_has_external_issue_tracker
       end.to change { project.has_external_issue_tracker}.to(false)
     end
+
+    it 'does not cache data when in a read-only GitLab instance' do
+      allow(Gitlab::Database).to receive(:read_only?) { true }
+
+      expect do
+        project.cache_has_external_issue_tracker
+      end.not_to change { project.has_external_issue_tracker }
+    end
+  end
+
+  describe '#cache_has_external_wiki' do
+    let(:project) { create(:project, has_external_wiki: nil) }
+
+    it 'stores true if there is any external_wikis' do
+      services = double(:service, external_wikis: [ExternalWikiService.new])
+      expect(project).to receive(:services).and_return(services)
+
+      expect do
+        project.cache_has_external_wiki
+      end.to change { project.has_external_wiki}.to(true)
+    end
+
+    it 'stores false if there is no external_wikis' do
+      services = double(:service, external_wikis: [])
+      expect(project).to receive(:services).and_return(services)
+
+      expect do
+        project.cache_has_external_wiki
+      end.to change { project.has_external_wiki}.to(false)
+    end
+
+    it 'does not cache data when in a read-only GitLab instance' do
+      allow(Gitlab::Database).to receive(:read_only?) { true }
+
+      expect do
+        project.cache_has_external_wiki
+      end.not_to change { project.has_external_wiki }
+    end
   end
 
   describe '#has_wiki?' do
@@ -2446,7 +2484,7 @@ describe Project do
         expect(project.migrate_to_hashed_storage!).to be_truthy
       end
 
-      it 'flags as readonly' do
+      it 'flags as read-only' do
         expect { project.migrate_to_hashed_storage! }.to change { project.repository_read_only }.to(true)
       end
 
@@ -2573,7 +2611,7 @@ describe Project do
         expect(project.migrate_to_hashed_storage!).to be_nil
       end
 
-      it 'does not flag as readonly' do
+      it 'does not flag as read-only' do
         expect { project.migrate_to_hashed_storage! }.not_to change { project.repository_read_only }
       end
     end
diff --git a/spec/requests/lfs_http_spec.rb b/spec/requests/lfs_http_spec.rb
index 27d09b8202e..eb4017e116b 100644
--- a/spec/requests/lfs_http_spec.rb
+++ b/spec/requests/lfs_http_spec.rb
@@ -824,6 +824,34 @@ describe 'Git LFS API and storage' do
     end
   end
 
+  describe 'when handling lfs batch request on a read-only GitLab instance' do
+    let(:authorization) { authorize_user }
+    let(:project) { create(:project) }
+    let(:path) { "#{project.http_url_to_repo}/info/lfs/objects/batch" }
+    let(:body) do
+      { 'objects' => [{ 'oid' => sample_oid, 'size' => sample_size }] }
+    end
+
+    before do
+      allow(Gitlab::Database).to receive(:read_only?) { true }
+      project.team << [user, :master]
+      enable_lfs
+    end
+
+    it 'responds with a 200 message on download' do
+      post_lfs_json path, body.merge('operation' => 'download'), headers
+
+      expect(response).to have_gitlab_http_status(200)
+    end
+
+    it 'responds with a 403 message on upload' do
+      post_lfs_json path, body.merge('operation' => 'upload'), headers
+
+      expect(response).to have_gitlab_http_status(403)
+      expect(json_response).to include('message' => 'You cannot write to this read-only GitLab instance.')
+    end
+  end
+
   describe 'when pushing a lfs object' do
     before do
       enable_lfs
diff --git a/spec/services/projects/hashed_storage_migration_service_spec.rb b/spec/services/projects/hashed_storage_migration_service_spec.rb
index 1b61207b550..aa1988d29d6 100644
--- a/spec/services/projects/hashed_storage_migration_service_spec.rb
+++ b/spec/services/projects/hashed_storage_migration_service_spec.rb
@@ -20,7 +20,7 @@ describe Projects::HashedStorageMigrationService do
         expect(gitlab_shell.exists?(project.repository_storage_path, "#{hashed_storage.disk_path}.wiki.git")).to be_truthy
       end
 
-      it 'updates project to be hashed and not readonly' do
+      it 'updates project to be hashed and not read-only' do
         service.execute
 
         expect(project.hashed_storage?).to be_truthy
diff --git a/spec/services/users/activity_service_spec.rb b/spec/services/users/activity_service_spec.rb
index fef4da0c76e..17eabad73be 100644
--- a/spec/services/users/activity_service_spec.rb
+++ b/spec/services/users/activity_service_spec.rb
@@ -38,6 +38,18 @@ describe Users::ActivityService do
         end
       end
     end
+
+    context 'when in GitLab read-only instance' do
+      before do
+        allow(Gitlab::Database).to receive(:read_only?).and_return(true)
+      end
+
+      it 'does not update last_activity_at' do
+        service.execute
+
+        expect(last_hour_user_ids).to eq([])
+      end
+    end
   end
 
   def last_hour_user_ids