env.rb in google-cloud-env-1.0.2

- old
+ new

@@ -1,12 +1,12 @@
-# Copyright 2017 Google Inc. All rights reserved.
+# Copyright 2017 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
-#     http://www.apache.org/licenses/LICENSE-2.0
+#     https://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
@@ -23,11 +23,11 @@
     # # Google Cloud hosting environment
     #
     # This library provides access to information about the application's
     # hosting environment if it is running on Google Cloud Platform. You may
     # use this library to determine which Google Cloud product is hosting your
-    # application (e.g. app engine, container engine), information about the
+    # application (e.g. App Engine, Kubernetes Engine), information about the
     # Google Cloud project hosting the application, information about the
     # virtual machine instance, authentication information, and so forth.
     #
     # ## Usage
     #
@@ -65,13 +65,14 @@
       # instance of the information from `Google::Cloud.env`. This constructor
       # is provided for internal testing and allows mocking of the data.
       #
       # @param [Hash] env Mock environment variables.
       # @param [Faraday::Connection] connection Faraday connection to use.
+      # @param [Hash] metadata_cache Mock cache.
       #
-      def initialize env: nil, connection: nil
-        @metadata_cache = {}
+      def initialize env: nil, connection: nil, metadata_cache: nil
+        @metadata_cache = metadata_cache || {}
         @env = env || ::ENV
         @connection = connection ||
                       ::Faraday.new(url: METADATA_HOST,
                                     request: { timeout: 0.1 })
       end
@@ -84,17 +85,19 @@
       def app_engine?
         env["GAE_INSTANCE"] ? true : false
       end
 
       ##
-      # Determine whether the application is running on Google Container Engine.
+      # Determine whether the application is running on Google Kubernetes
+      # Engine (GKE).
       #
       # @return [Boolean]
       #
-      def container_engine?
-        container_engine_cluster_name ? true : false
+      def kubernetes_engine?
+        kubernetes_engine_cluster_name ? true : false
       end
+      alias container_engine? kubernetes_engine?
 
       ##
       # Determine whether the application is running on Google Cloud Shell.
       #
       # @return [Boolean]
@@ -104,11 +107,11 @@
       end
 
       ##
       # Determine whether the application is running on Google Compute Engine.
       #
-      # Note that most other products (e.g. App Engine, Container Engine,
+      # Note that most other products (e.g. App Engine, Kubernetes Engine,
       # Cloud Shell) themselves use Compute Engine under the hood, so this
       # method will return true for all the above products. If you want to
       # determine whether the application is running on a "raw" Compute Engine
       # VM without using a higher level hosting product, use
       # {Env#raw_compute_engine?}.
@@ -120,16 +123,16 @@
       end
 
       ##
       # Determine whether the application is running on "raw" Google Compute
       # Engine without using a higher level hosting product such as App
-      # Engine or Container Engine.
+      # Engine or Kubernetes Engine.
       #
       # @return [Boolean]
       #
       def raw_compute_engine?
-        !app_engine? && !cloud_shell? && metadata? && !container_engine?
+        !app_engine? && !cloud_shell? && metadata? && !kubernetes_engine?
       end
 
       ##
       # Returns the unique string ID of the project hosting the application,
       # or `nil` if the application is not running on Google Cloud.
@@ -270,30 +273,40 @@
         result = env["GAE_MEMORY_MB"]
         result.nil? ? nil : result.to_i
       end
 
       ##
-      # Returns the name of the Container Engine cluster hosting the
+      # Returns the name of the Kubernetes Engine cluster hosting the
       # application, or `nil` if the current code is not running in
-      # Container Engine.
+      # Kubernetes Engine.
       #
       # @return [String,nil]
       #
-      def container_engine_cluster_name
+      def kubernetes_engine_cluster_name
         instance_attribute "cluster-name"
       end
+      alias container_engine_cluster_name kubernetes_engine_cluster_name
 
       ##
-      # Returns the name of the Container Engine namespace hosting the
+      # Returns the name of the Kubernetes Engine namespace hosting the
       # application, or `nil` if the current code is not running in
-      # Container Engine.
+      # Kubernetes Engine.
       #
       # @return [String,nil]
       #
-      def container_engine_namespace_id
-        env["GKE_NAMESPACE_ID"]
+      def kubernetes_engine_namespace_id
+        # The Kubernetes namespace is difficult to obtain without help from
+        # the application using the Downward API. The environment variable
+        # below is set in some older versions of GKE, and the file below is
+        # present in Kubernetes as of version 1.9, but it is possible that
+        # alternatives will need to be found in the future.
+        env["GKE_NAMESPACE_ID"] ||
+          ::IO.read("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
+      rescue SystemCallError
+        nil
       end
+      alias container_engine_namespace_id kubernetes_engine_namespace_id
 
       ##
       # Determine whether the Google Compute Engine Metadata Service is running.
       #
       # @return [Boolean]
@@ -302,11 +315,12 @@
         unless metadata_cache.include?(METADATA_ROOT_PATH)
           begin
             resp = connection.get METADATA_ROOT_PATH
             metadata_cache[METADATA_ROOT_PATH] = \
               resp.status == 200 && resp.headers["Metadata-Flavor"] == "Google"
-          rescue ::Faraday::TimeoutError, ::Faraday::ConnectionFailed
+          rescue ::Faraday::TimeoutError, ::Faraday::ConnectionFailed,
+                 Errno::EHOSTDOWN
             metadata_cache[METADATA_ROOT_PATH] = false
           end
         end
         metadata_cache[METADATA_ROOT_PATH]
       end
@@ -327,10 +341,11 @@
           begin
             resp = connection.get path do |req|
               req.headers = { "Metadata-Flavor" => "Google" }
             end
             metadata_cache[path] = resp.status == 200 ? resp.body.strip : nil
-          rescue ::Faraday::TimeoutError, ::Faraday::ConnectionFailed
+          rescue ::Faraday::TimeoutError, ::Faraday::ConnectionFailed,
+                 Errno::EHOSTDOWN
             metadata_cache[path] = nil
           end
         end
         metadata_cache[path]
       end