1 files changed, 117 insertions, 0 deletions
diff --git a/lib/gitlab/kubernetes/deployment.rb b/lib/gitlab/kubernetes/deployment.rb
new file mode 100644
index 00000000000..55ed9a7517e
--- /dev/null
+++ b/lib/gitlab/kubernetes/deployment.rb
@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    class Deployment
+      include Gitlab::Utils::StrongMemoize
+
+      STABLE_TRACK_VALUE = 'stable'.freeze
+
+      def initialize(attributes = {}, pods: [])
+        @attributes = attributes
+        @pods = pods
+      end
+
+      def name
+        metadata['name'] || 'unknown'
+      end
+
+      def labels
+        metadata.fetch('labels', {})
+      end
+
+      def annotations
+        metadata.fetch('annotations', {})
+      end
+
+      def track
+        labels.fetch('track', STABLE_TRACK_VALUE)
+      end
+
+      def stable?
+        track == 'stable'
+      end
+
+      def order
+        stable? ? 1 : 0
+      end
+
+      def outdated?
+        observed_generation < generation
+      end
+
+      def wanted_instances
+        spec.fetch('replicas', 0)
+      end
+
+      def created_instances
+        filtered_pods_by_track.map do |pod|
+          pod_metadata = pod.fetch('metadata', {})
+          pod_name = pod_metadata['name'] || pod_metadata['generateName']
+          pod_status = pod.dig('status', 'phase')
+
+          deployment_instance(pod_name: pod_name, pod_status: pod_status)
+        end
+      end
+
+      # These are replicas that did not get created yet,
+      # So they still do not have any associated pod,
+      # these are marked as pending instances.
+      def not_created_instances
+        pending_instances_count = wanted_instances - filtered_pods_by_track.count
+
+        return [] if pending_instances_count <= 0
+
+        Array.new(pending_instances_count, deployment_instance(pod_name: 'Not provided', pod_status: 'Pending'))
+      end
+
+      def filtered_pods_by_track
+        strong_memoize(:filtered_pods_by_track) do
+          @pods.select { |pod| has_same_track?(pod) }
+        end
+      end
+
+      def instances
+        created_instances + not_created_instances
+      end
+
+      private
+
+      def deployment_instance(pod_name:, pod_status:)
+        {
+          status: pod_status&.downcase,
+          pod_name: pod_name,
+          tooltip: "#{pod_name} (#{pod_status})",
+          track: track,
+          stable: stable?
+        }
+      end
+
+      def has_same_track?(pod)
+        pod_track = pod.dig('metadata', 'labels', 'track') || STABLE_TRACK_VALUE
+
+        pod_track == track
+      end
+
+      def metadata
+        @attributes.fetch('metadata', {})
+      end
+
+      def spec
+        @attributes.fetch('spec', {})
+      end
+
+      def status
+        @attributes.fetch('status', {})
+      end
+
+      def generation
+        metadata.fetch('generation', 0)
+      end
+
+      def observed_generation
+        status.fetch('observedGeneration', 0)
+      end
+    end
+  end
+end