Make KUBECONFIG nil if KUBE_TOKEN is nil

Having an invalid KUBECONFIG without a token in it is not helpful. This
only became possible recently now that we are creating a separate
namespace and service account (and hence token) to send to the runners.
This led to somewhat surprising results when troubleshooting
https://gitlab.com/gitlab-org/gitlab-ce/issues/53879 as I found that the
KUBECONFIG was still being passed but KUBE_TOKEN was not. These things
really should have been linked.

Furthermore now that we are also using the [presence of KUBECONFIG to
decide whether or not to run build steps in Auto
DevOps](https://gitlab.com/gitlab-org/gitlab-ce/blob/294d15be3e9497e7b67e1f9131ce9d5c0d68406c/lib/gitlab/ci/templates/Auto-DevOps.gitlab-ci.yml#L164)
I think it makes even more sense to ensure that KUBECONFIG is a complete
config if passed to a job.

1 files changed, 14 insertions, 10 deletions

diff --git a/spec/lib/gitlab/kubernetes_spec.rb b/spec/lib/gitlab/kubernetes_spec.rb
index 5c03a2ce7d3..f326d57e9c6 100644
--- a/spec/lib/gitlab/kubernetes_spec.rb
+++ b/spec/lib/gitlab/kubernetes_spec.rb
@@ -48,26 +48,30 @@ describe Gitlab::Kubernetes do
   end
 
   describe '#to_kubeconfig' do
+    let(:token) { 'TOKEN' }
+    let(:ca_pem) { 'PEM' }
+
     subject do
       to_kubeconfig(
         url: 'https://kube.domain.com',
         namespace: 'NAMESPACE',
-        token: 'TOKEN',
-        ca_pem: ca_pem)
+        token: token,
+        ca_pem: ca_pem
+      )
     end
 
-    context 'when CA PEM is provided' do
-      let(:ca_pem) { 'PEM' }
-      let(:path) { expand_fixture_path('config/kubeconfig.yml') }
-
-      it { is_expected.to eq(YAML.load_file(path)) }
-    end
+    it { expect(YAML.safe_load(subject)).to eq(YAML.load_file(expand_fixture_path('config/kubeconfig.yml'))) }
 
     context 'when CA PEM is not provided' do
       let(:ca_pem) { nil }
-      let(:path) { expand_fixture_path('config/kubeconfig-without-ca.yml') }
 
-      it { is_expected.to eq(YAML.load_file(path)) }
+      it { expect(YAML.safe_load(subject)).to eq(YAML.load_file(expand_fixture_path('config/kubeconfig-without-ca.yml'))) }
+    end
+
+    context 'when token is not provided' do
+      let(:token) { nil }
+
+      it { is_expected.to be_nil }
     end
   end