1 files changed, 111 insertions, 0 deletions
diff --git a/lib/gitlab/pages/deployment_update.rb b/lib/gitlab/pages/deployment_update.rb
new file mode 100644
index 00000000000..2f5c6938e2a
--- /dev/null
+++ b/lib/gitlab/pages/deployment_update.rb
@@ -0,0 +1,111 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Pages
+    class DeploymentUpdate
+      include ActiveModel::Validations
+
+      PUBLIC_DIR = 'public'
+
+      validate :validate_state, unless: -> { errors.any? }
+      validate :validate_outdated_sha, unless: -> { errors.any? }
+      validate :validate_max_size, unless: -> { errors.any? }
+      validate :validate_public_folder, unless: -> { errors.any? }
+      validate :validate_max_entries, unless: -> { errors.any? }
+
+      def initialize(project, build)
+        @project = project
+        @build = build
+      end
+
+      def latest?
+        # check if sha for the ref is still the most recent one
+        # this helps in case when multiple deployments happens
+        sha == latest_sha
+      end
+
+      def entries_count
+        # we're using the full archive and pages daemon needs to read it
+        # so we want the total count from entries, not only "public/" directory
+        # because it better approximates work we need to do before we can serve the site
+        @entries_count = build.artifacts_metadata_entry("", recursive: true).entries.count
+      end
+
+      private
+
+      attr_reader :build, :project
+
+      def validate_state
+        errors.add(:base, 'missing pages artifacts') unless build.artifacts?
+        errors.add(:base, 'missing artifacts metadata') unless build.artifacts_metadata?
+      end
+
+      def validate_max_size
+        if total_size > max_size
+          errors.add(:base, "artifacts for pages are too large: #{total_size}")
+        end
+      end
+
+      # Calculate page size after extract
+      def total_size
+        @total_size ||= build.artifacts_metadata_entry(PUBLIC_DIR + '/', recursive: true).total_size
+      end
+
+      def max_size_from_settings
+        Gitlab::CurrentSettings.max_pages_size.megabytes
+      end
+
+      def max_size
+        max_pages_size = max_size_from_settings
+
+        return ::Gitlab::Pages::MAX_SIZE if max_pages_size == 0
+
+        max_pages_size
+      end
+
+      def validate_max_entries
+        if pages_file_entries_limit > 0 && entries_count > pages_file_entries_limit
+          errors.add(
+            :base,
+            "pages site contains #{entries_count} file entries, while limit is set to #{pages_file_entries_limit}"
+          )
+        end
+      end
+
+      def validate_public_folder
+        if total_size <= 0
+          errors.add(:base, 'Error: The `public/` folder is missing, or not declared in `.gitlab-ci.yml`.')
+        end
+      end
+
+      def pages_file_entries_limit
+        project.actual_limits.pages_file_entries
+      end
+
+      def validate_outdated_sha
+        return if latest?
+
+        # use pipeline_id in case the build is retried
+        last_deployed_pipeline_id = project.pages_metadatum&.pages_deployment&.ci_build&.pipeline_id
+
+        return unless last_deployed_pipeline_id
+        return if last_deployed_pipeline_id <= build.pipeline_id
+
+        errors.add(:base, 'build SHA is outdated for this ref')
+      end
+
+      def latest_sha
+        project.commit(build.ref).try(:sha).to_s
+      ensure
+        # Close any file descriptors that were opened and free libgit2 buffers
+        project.cleanup
+      end
+
+      def sha
+        build.sha
+      end
+    end
+  end
+end
+
+Gitlab::Pages::DeploymentUpdate.prepend_mod_with('Gitlab::Pages::DeploymentUpdate')