Do not allow local urls in Kubernetes form

Use existing `public_url` validation to block various local urls. Note
that this validation will allow local urls if the "Allow requests to the
local network from hooks and services" admin setting is enabled.

Block KubeClient from using local addresses

It will also respect `allow_local_requests_from_hooks_and_services` so
if that is enabled KubeClinet will allow local addresses

2 files changed, 46 insertions, 0 deletions

diff --git a/spec/lib/gitlab/kubernetes/kube_client_spec.rb b/spec/lib/gitlab/kubernetes/kube_client_spec.rb
index 02364e92149..978e64c4407 100644
--- a/spec/lib/gitlab/kubernetes/kube_client_spec.rb
+++ b/spec/lib/gitlab/kubernetes/kube_client_spec.rb
@@ -50,6 +50,36 @@ describe Gitlab::Kubernetes::KubeClient do
     end
   end
 
+  describe '#initialize' do
+    shared_examples 'local address' do
+      it 'blocks local addresses' do
+        expect { client }.to raise_error(Gitlab::UrlBlocker::BlockedUrlError)
+      end
+
+      context 'when local requests are allowed' do
+        before do
+          stub_application_setting(allow_local_requests_from_hooks_and_services: true)
+        end
+
+        it 'allows local addresses' do
+          expect { client }.not_to raise_error
+        end
+      end
+    end
+
+    context 'localhost address' do
+      let(:api_url) { 'http://localhost:22' }
+
+      it_behaves_like 'local address'
+    end
+
+    context 'private network address' do
+      let(:api_url) { 'http://192.168.1.2:3003' }
+
+      it_behaves_like 'local address'
+    end
+  end
+
   describe '#core_client' do
     subject { client.core_client }
 
diff --git a/spec/models/clusters/platforms/kubernetes_spec.rb b/spec/models/clusters/platforms/kubernetes_spec.rb
index c273fa7e164..8dfc9297d0a 100644
--- a/spec/models/clusters/platforms/kubernetes_spec.rb
+++ b/spec/models/clusters/platforms/kubernetes_spec.rb
@@ -98,6 +98,22 @@ describe Clusters::Platforms::Kubernetes, :use_clean_rails_memory_store_caching
 
         it { expect(kubernetes.save).to be_truthy }
       end
+
+      context 'when api_url is localhost' do
+        let(:api_url) { 'http://localhost:22' }
+
+        it { expect(kubernetes.save).to be_falsey }
+
+        context 'Application settings allows local requests' do
+          before do
+            allow(ApplicationSetting)
+              .to receive(:current)
+              .and_return(ApplicationSetting.build_from_defaults(allow_local_requests_from_hooks_and_services: true))
+          end
+
+          it { expect(kubernetes.save).to be_truthy }
+        end
+      end
     end
 
     context 'when validates token' do