1 files changed, 88 insertions, 0 deletions
diff --git a/app/services/pod_logs/kubernetes_service.rb b/app/services/pod_logs/kubernetes_service.rb
new file mode 100644
index 00000000000..8f12b364e73
--- /dev/null
+++ b/app/services/pod_logs/kubernetes_service.rb
@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+module PodLogs
+  class KubernetesService < BaseService
+    LOGS_LIMIT = 500.freeze
+    REPLACEMENT_CHAR = "\u{FFFD}"
+
+    EncodingHelperError = Class.new(StandardError)
+
+    steps :check_arguments,
+          :check_param_lengths,
+          :get_raw_pods,
+          :get_pod_names,
+          :check_pod_name,
+          :check_container_name,
+          :pod_logs,
+          :encode_logs_to_utf8,
+          :split_logs,
+          :filter_return_keys
+
+    self.reactive_cache_worker_finder = ->(id, _cache_key, namespace, params) { new(::Clusters::Cluster.find(id), namespace, params: params) }
+
+    private
+
+    def pod_logs(result)
+      result[:logs] = cluster.kubeclient.get_pod_log(
+        result[:pod_name],
+        namespace,
+        container: result[:container_name],
+        tail_lines: LOGS_LIMIT,
+        timestamps: true
+      ).body
+
+      success(result)
+    rescue Kubeclient::ResourceNotFoundError
+      error(_('Pod not found'))
+    rescue Kubeclient::HttpError => e
+      ::Gitlab::ErrorTracking.track_exception(e)
+
+      error(_('Kubernetes API returned status code: %{error_code}') % {
+        error_code: e.error_code
+      })
+    end
+
+    # Check https://gitlab.com/gitlab-org/gitlab/issues/34965#note_292261879
+    # for more details on why this is necessary.
+    def encode_logs_to_utf8(result)
+      return success(result) if result[:logs].nil?
+      return success(result) if result[:logs].encoding == Encoding::UTF_8
+
+      result[:logs] = encode_utf8(result[:logs])
+
+      success(result)
+    rescue EncodingHelperError
+      error(_('Unable to convert Kubernetes logs encoding to UTF-8'))
+    end
+
+    def split_logs(result)
+      result[:logs] = result[:logs].strip.lines(chomp: true).map do |line|
+        # message contains a RFC3339Nano timestamp, then a space, then the log line.
+        # resolution of the nanoseconds can vary, so we split on the first space
+        values = line.split(' ', 2)
+        {
+          timestamp: values[0],
+          message: values[1]
+        }
+      end
+
+      success(result)
+    end
+
+    def encode_utf8(logs)
+      utf8_logs = Gitlab::EncodingHelper.encode_utf8(logs.dup, replace: REPLACEMENT_CHAR)
+
+      # Gitlab::EncodingHelper.encode_utf8 can return '' or nil if an exception
+      # is raised while encoding. We prefer to return an error rather than wrongly
+      # display blank logs.
+      no_utf8_logs = logs.present? && utf8_logs.blank?
+      unexpected_encoding = utf8_logs&.encoding != Encoding::UTF_8
+
+      if no_utf8_logs || unexpected_encoding
+        raise EncodingHelperError, 'Could not convert Kubernetes logs to UTF-8'
+      end
+
+      utf8_logs
+    end
+  end
+end