Extend Cluster Applications to allow installation of Prometheus

1 files changed, 69 insertions, 0 deletions

diff --git a/lib/gitlab/kubernetes/helm/pod.rb b/lib/gitlab/kubernetes/helm/pod.rb
new file mode 100644
index 00000000000..233f6bf6227
--- /dev/null
+++ b/lib/gitlab/kubernetes/helm/pod.rb
@@ -0,0 +1,69 @@
+module Gitlab
+  module Kubernetes
+    module Helm
+      class Pod
+        def initialize(command, namespace_name, kubeclient)
+          @command = command
+          @namespace_name = namespace_name
+          @kubeclient = kubeclient
+        end
+
+        def generate
+          spec = { containers: [container_specification], restartPolicy: 'Never' }
+          if command.chart_values_file
+            generate_config_map
+            spec['volumes'] = volumes_specification
+          end
+          ::Kubeclient::Resource.new(metadata: metadata, spec: spec)
+        end
+
+        private
+
+        attr_reader :command, :namespace_name, :kubeclient
+
+        def container_specification
+          container = {
+            name: 'helm',
+            image: 'alpine:3.6',
+            env: generate_pod_env(command),
+            command: %w(/bin/sh),
+            args: %w(-c $(COMMAND_SCRIPT))
+          }
+          container[:volumeMounts] = volume_mounts_specification if command.chart_values_file
+          container
+        end
+
+        def labels
+          { 'gitlab.org/action': 'install', 'gitlab.org/application': command.name }
+        end
+
+        def metadata
+          { name: command.pod_name, namespace: namespace_name, labels: labels }
+        end
+
+        def volume_mounts_specification
+          [{ name: 'config-volume', mountPath: '/etc/config' }]
+        end
+
+        def volumes_specification
+          [{ name: 'config-volume', configMap: { name: 'values-config' } }]
+        end
+
+        def generate_pod_env(command)
+          {
+            HELM_VERSION: Gitlab::Kubernetes::Helm::HELM_VERSION,
+            TILLER_NAMESPACE: namespace_name,
+            COMMAND_SCRIPT: command.generate_script(namespace_name)
+          }.map { |key, value| { name: key, value: value } }
+        end
+
+        def generate_config_map
+          resource = ::Kubeclient::Resource.new
+          resource.metadata = { name: 'values-config', namespace: namespace_name }
+          resource.data = YAML.load_file(command.chart_values_file)
+          kubeclient.create_config_map(resource)
+        end
+      end
+    end
+  end
+end