1 files changed, 112 insertions, 0 deletions
diff --git a/app/finders/clusters/knative_services_finder.rb b/app/finders/clusters/knative_services_finder.rb
new file mode 100644
index 00000000000..7d3b53ef663
--- /dev/null
+++ b/app/finders/clusters/knative_services_finder.rb
@@ -0,0 +1,112 @@
+# frozen_string_literal: true
+module Clusters
+  class KnativeServicesFinder
+    include ReactiveCaching
+    include Gitlab::Utils::StrongMemoize
+
+    KNATIVE_STATES = {
+      'checking' => 'checking',
+      'installed' => 'installed',
+      'not_found' => 'not_found'
+    }.freeze
+
+    self.reactive_cache_key = ->(finder) { finder.model_name }
+    self.reactive_cache_worker_finder = ->(_id, *cache_args) { from_cache(*cache_args) }
+
+    attr_reader :cluster, :project
+
+    def initialize(cluster, project)
+      @cluster = cluster
+      @project = project
+    end
+
+    def with_reactive_cache_memoized(*cache_args, &block)
+      strong_memoize(:reactive_cache) do
+        with_reactive_cache(*cache_args, &block)
+      end
+    end
+
+    def clear_cache!
+      clear_reactive_cache!(*cache_args)
+    end
+
+    def self.from_cache(cluster_id, project_id)
+      cluster = Clusters::Cluster.find(cluster_id)
+      project = ::Project.find(project_id)
+
+      new(cluster, project)
+    end
+
+    def calculate_reactive_cache(*)
+      # read_services calls knative_client.discover implicitily. If we stop
+      # detecting services but still want to detect knative, we'll need to
+      # explicitily call: knative_client.discover
+      #
+      # We didn't create it separately to avoid 2 cluster requests.
+      ksvc = read_services
+      pods = knative_client.discovered ? read_pods : []
+      { services: ksvc, pods: pods, knative_detected: knative_client.discovered }
+    end
+
+    def services
+      return [] unless search_namespace
+
+      cached_data = with_reactive_cache_memoized(*cache_args) { |data| data }
+      cached_data.to_h.fetch(:services, [])
+    end
+
+    def cache_args
+      [cluster.id, project.id]
+    end
+
+    def service_pod_details(service)
+      cached_data = with_reactive_cache_memoized(*cache_args) { |data| data }
+      cached_data.to_h.fetch(:pods, []).select do |pod|
+        filter_pods(pod, service)
+      end
+    end
+
+    def knative_detected
+      cached_data = with_reactive_cache_memoized(*cache_args) { |data| data }
+
+      knative_state = cached_data.to_h[:knative_detected]
+
+      return KNATIVE_STATES['checking'] if knative_state.nil?
+      return KNATIVE_STATES['installed'] if knative_state
+
+      KNATIVE_STATES['uninstalled']
+    end
+
+    def model_name
+      self.class.name.underscore.tr('/', '_')
+    end
+
+    private
+
+    def search_namespace
+      @search_namespace ||= cluster.kubernetes_namespace_for(project)
+    end
+
+    def knative_client
+      cluster.kubeclient.knative_client
+    end
+
+    def filter_pods(pod, service)
+      pod["metadata"]["labels"]["serving.knative.dev/service"] == service
+    end
+
+    def read_services
+      knative_client.get_services(namespace: search_namespace).as_json
+    rescue Kubeclient::ResourceNotFoundError
+      []
+    end
+
+    def read_pods
+      cluster.kubeclient.core_client.get_pods(namespace: search_namespace).as_json
+    end
+
+    def id
+      nil
+    end
+  end
+end