Extend Cluster Applications to allow installation of Prometheus

3 files changed, 266 insertions, 0 deletions

diff --git a/spec/lib/gitlab/kubernetes/helm/api_spec.rb b/spec/lib/gitlab/kubernetes/helm/api_spec.rb
new file mode 100644
index 00000000000..69112fe90b1
--- /dev/null
+++ b/spec/lib/gitlab/kubernetes/helm/api_spec.rb
@@ -0,0 +1,69 @@
+require 'spec_helper'
+
+describe Gitlab::Kubernetes::Helm::Api do
+  let(:client) { double('kubernetes client') }
+  let(:helm) { described_class.new(client) }
+  let(:gitlab_namespace) { Gitlab::Kubernetes::Helm::NAMESPACE }
+  let(:namespace) { Gitlab::Kubernetes::Namespace.new(gitlab_namespace, client) }
+  let(:install_helm) { true }
+  let(:chart) { 'stable/a_chart' }
+  let(:application_name) { 'app_name' }
+  let(:command) { Gitlab::Kubernetes::Helm::InstallCommand.new(application_name, install_helm: install_helm, chart: chart) }
+  subject { helm }
+
+  before do
+    allow(Gitlab::Kubernetes::Namespace).to receive(:new).with(gitlab_namespace, client).and_return(namespace)
+  end
+
+  describe '#initialize' do
+    it 'creates a namespace object' do
+      expect(Gitlab::Kubernetes::Namespace).to receive(:new).with(gitlab_namespace, client)
+
+      subject
+    end
+  end
+
+  describe '#install' do
+    before do
+      allow(client).to receive(:create_pod).and_return(nil)
+      allow(namespace).to receive(:ensure_exists!).once
+    end
+
+    it 'ensures the namespace exists before creating the POD' do
+      expect(namespace).to receive(:ensure_exists!).once.ordered
+      expect(client).to receive(:create_pod).once.ordered
+
+      subject.install(command)
+    end
+  end
+
+  describe '#installation_status' do
+    let(:phase) { Gitlab::Kubernetes::Pod::RUNNING }
+    let(:pod) { Kubeclient::Resource.new(status: { phase: phase }) } # partial representation
+
+    it 'fetches POD phase from kubernetes cluster' do
+      expect(client).to receive(:get_pod).with(command.pod_name, gitlab_namespace).once.and_return(pod)
+
+      expect(subject.installation_status(command.pod_name)).to eq(phase)
+    end
+  end
+
+  describe '#installation_log' do
+    let(:log) { 'some output' }
+    let(:response) { RestClient::Response.new(log) }
+
+    it 'fetches POD phase from kubernetes cluster' do
+      expect(client).to receive(:get_pod_log).with(command.pod_name, gitlab_namespace).once.and_return(response)
+
+      expect(subject.installation_log(command.pod_name)).to eq(log)
+    end
+  end
+
+  describe '#delete_installation_pod!' do
+    it 'deletes the POD from kubernetes cluster' do
+      expect(client).to receive(:delete_pod).with(command.pod_name, gitlab_namespace).once
+
+      subject.delete_installation_pod!(command.pod_name)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb
new file mode 100644
index 00000000000..4afe48e72ad
--- /dev/null
+++ b/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb
@@ -0,0 +1,111 @@
+require 'rails_helper'
+
+describe Gitlab::Kubernetes::Helm::InstallCommand do
+  let(:prometheus) { create(:clusters_applications_prometheus) }
+
+  describe "#initialize" do
+    context "With all the params" do
+      subject { described_class.new(prometheus.name, install_helm: true, chart: prometheus.chart, chart_values_file: prometheus.chart_values_file) }
+
+      it 'should assign all parameters' do
+        expect(subject.name).to eq(prometheus.name)
+        expect(subject.install_helm).to be_truthy
+        expect(subject.chart).to eq(prometheus.chart)
+        expect(subject.chart_values_file).to eq("#{Rails.root}/vendor/prometheus/values.yaml")
+      end
+    end
+
+    context 'when install_helm is not set' do
+      subject { described_class.new(prometheus.name, chart: prometheus.chart, chart_values_file: true) }
+
+      it 'should set install_helm as false' do
+        expect(subject.install_helm).to be_falsy
+      end
+    end
+
+    context 'when chart is not set' do
+      subject { described_class.new(prometheus.name, install_helm: true) }
+
+      it 'should set chart as nil' do
+        expect(subject.chart).to be_falsy
+      end
+    end
+
+    context 'when chart_values_file is not set' do
+      subject { described_class.new(prometheus.name, install_helm: true, chart: prometheus.chart) }
+
+      it 'should set chart_values_file as nil' do
+        expect(subject.chart_values_file).to be_falsy
+      end
+    end
+  end
+
+  describe "#generate_script" do
+    let(:install_command) { described_class.new(prometheus.name, install_helm: install_helm) }
+    let(:client) { double('kubernetes client') }
+    let(:namespace) { Gitlab::Kubernetes::Namespace.new(Gitlab::Kubernetes::Helm::NAMESPACE, client) }
+    subject { install_command.send(:generate_script, namespace.name) }
+
+    context 'when install helm is true' do
+      let(:install_helm) { true }
+      let(:command) do
+        <<~MSG
+        set -eo pipefail
+        apk add -U ca-certificates openssl >/dev/null
+        wget -q -O - https://kubernetes-helm.storage.googleapis.com/helm-v2.7.0-linux-amd64.tar.gz | tar zxC /tmp >/dev/null
+        mv /tmp/linux-amd64/helm /usr/bin/
+
+        helm init >/dev/null
+        MSG
+      end
+
+      it 'should return appropriate command' do
+        is_expected.to eq(command)
+      end
+    end
+
+    context 'when install helm is false' do
+      let(:install_helm) { false }
+      let(:command) do
+        <<~MSG
+        set -eo pipefail
+        apk add -U ca-certificates openssl >/dev/null
+        wget -q -O - https://kubernetes-helm.storage.googleapis.com/helm-v2.7.0-linux-amd64.tar.gz | tar zxC /tmp >/dev/null
+        mv /tmp/linux-amd64/helm /usr/bin/
+
+        helm init --client-only >/dev/null
+        MSG
+      end
+
+      it 'should return appropriate command' do
+        is_expected.to eq(command)
+      end
+    end
+
+    context 'when chart is present' do
+      let(:install_command) { described_class.new(prometheus.name, chart: prometheus.chart) }
+      let(:command) do
+        <<~MSG.chomp
+        set -eo pipefail
+        apk add -U ca-certificates openssl >/dev/null
+        wget -q -O - https://kubernetes-helm.storage.googleapis.com/helm-v2.7.0-linux-amd64.tar.gz | tar zxC /tmp >/dev/null
+        mv /tmp/linux-amd64/helm /usr/bin/
+
+        helm init --client-only >/dev/null
+        helm install #{prometheus.chart} --name #{prometheus.name} --namespace #{namespace.name} >/dev/null
+        MSG
+      end
+
+      it 'should return appropriate command' do
+        is_expected.to eq(command)
+      end
+    end
+  end
+
+  describe "#pod_name" do
+    let(:install_command) { described_class.new(prometheus.name, install_helm: true, chart: prometheus.chart, chart_values_file: true) }
+    subject { install_command.send(:pod_name) }
+
+    it { is_expected.to eq('install-prometheus') }
+  end
+end
diff --git a/spec/lib/gitlab/kubernetes/helm/pod_spec.rb b/spec/lib/gitlab/kubernetes/helm/pod_spec.rb
new file mode 100644
index 00000000000..906b10b96d4
--- /dev/null
+++ b/spec/lib/gitlab/kubernetes/helm/pod_spec.rb
@@ -0,0 +1,86 @@
+require 'rails_helper'
+
+describe Gitlab::Kubernetes::Helm::Pod do
+  describe '#generate' do
+    let(:cluster) { create(:cluster) }
+    let(:app) {  create(:clusters_applications_prometheus, cluster: cluster) }
+    let(:command) {  app.install_command }
+    let(:client) { double('kubernetes client') }
+    let(:namespace) { Gitlab::Kubernetes::Namespace.new(Gitlab::Kubernetes::Helm::NAMESPACE, client) }
+    subject { described_class.new(command, namespace.name, client) }
+
+    before do
+      allow(client).to receive(:create_config_map).and_return(nil)
+    end
+
+    shared_examples 'helm pod' do
+      it 'should generate a Kubeclient::Resource' do
+        expect(subject.generate).to be_a_kind_of(Kubeclient::Resource)
+      end
+
+      it 'should generate the appropriate metadata' do
+        metadata = subject.generate.metadata
+        expect(metadata.name).to eq("install-#{app.name}")
+        expect(metadata.namespace).to eq('gitlab-managed-apps')
+        expect(metadata.labels['gitlab.org/action']).to eq('install')
+        expect(metadata.labels['gitlab.org/application']).to eq(app.name)
+      end
+
+      it 'should generate a container spec' do
+        spec = subject.generate.spec
+        expect(spec.containers.count).to eq(1)
+      end
+
+      it 'should generate the appropriate specifications for the container' do
+        container = subject.generate.spec.containers.first
+        expect(container.name).to eq('helm')
+        expect(container.image).to eq('alpine:3.6')
+        expect(container.env.count).to eq(3)
+        expect(container.env.map(&:name)).to match_array([:HELM_VERSION, :TILLER_NAMESPACE, :COMMAND_SCRIPT])
+        expect(container.command).to match_array(["/bin/sh"])
+        expect(container.args).to match_array(["-c", "$(COMMAND_SCRIPT)"])
+      end
+
+      it 'should include a never restart policy' do
+        spec = subject.generate.spec
+        expect(spec.restartPolicy).to eq('Never')
+      end
+    end
+
+    context 'with a configuration file' do
+      it_behaves_like 'helm pod'
+
+      it 'should include volumes for the container' do
+        container = subject.generate.spec.containers.first
+        expect(container.volumeMounts.first['name']).to eq('config-volume')
+        expect(container.volumeMounts.first['mountPath']).to eq('/etc/config')
+      end
+
+      it 'should include a volume inside the specification' do
+        spec = subject.generate.spec
+        expect(spec.volumes.first['name']).to eq('config-volume')
+      end
+
+      it 'should mount configMap specification in the volume' do
+        spec = subject.generate.spec
+        expect(spec.volumes.first.configMap['name']).to eq('values-config')
+      end
+    end
+
+    context 'without a configuration file' do
+      let(:app) { create(:clusters_applications_ingress, cluster: cluster) }
+
+      it_behaves_like 'helm pod'
+
+      it 'should not include volumeMounts inside the container' do
+        container = subject.generate.spec.containers.first
+        expect(container.volumeMounts).to be_nil
+      end
+
+      it 'should not a volume inside the specification' do
+        spec = subject.generate.spec
+        expect(spec.volumes).to be_nil
+      end
+    end
+  end
+end