Merge branch 'sh-geo-handle-no-current-geo-node' into 'master'

Gracefully handle case where current instance is not a Geo Node

See merge request gitlab-org/gitlab-ee!2977

app/controllers/admin/application_controller.rb

@@ -12,6 +12,7 @@ class Admin::ApplicationController < ApplicationController
 
   def display_geo_information
     return unless Gitlab::Geo.secondary?
+    return unless Gitlab::Geo.primary_node_configured?
 
     primary_node = view_context.link_to('primary node', Gitlab::Geo.primary_node.url)
     flash.now[:notice] = "You are on a secondary (read-only) Geo node. If you want to make any changes, you must visit the #{primary_node}.".html_safe

app/services/geo/node_status_service.rb

@@ -39,6 +39,8 @@ module Geo
 
             Array([message, details].compact.join("\n"))
           end
+        rescue Gitlab::Geo::GeoNodeNotFoundError
+          ['This GitLab instance does not appear to be configured properly as a Geo node. Make sure the URLs are using the correct fully-qualified domain names.']
         rescue OpenSSL::Cipher::CipherError
           ['Error decrypting the Geo secret from the database. Check that the primary uses the correct db_key_base.']
         rescue HTTParty::Error, Timeout::Error, SocketError, SystemCallError, OpenSSL::SSL::SSLError => e

app/views/layouts/nav/_dashboard.html.haml

@@ -60,7 +60,7 @@
       = link_to sherlock_transactions_path, class: 'admin-icon', title: 'Sherlock Transactions',
         data: {toggle: 'tooltip', placement: 'bottom', container: 'body'} do
         = icon('tachometer fw')
-  - if Gitlab::Geo.secondary?
+  - if Gitlab::Geo.secondary? && Gitlab::Geo.primary_node_configured?
     %li
       = link_to Gitlab::Geo.primary_node.url, title: 'Go to primary node', data: {toggle: 'tooltip', placement: 'bottom', container: 'body'} do
         = icon('globe fw')

lib/gitlab/geo.rb

 module Gitlab
   module Geo
     OauthApplicationUndefinedError = Class.new(StandardError)
+    GeoNodeNotFoundError = Class.new(StandardError)
 
     CACHE_KEYS = %i(
       geo_primary_node
@@ -49,6 +50,10 @@ module Gitlab
       Rails.configuration.respond_to?(:geo_database)
     end
 
+    def self.primary_node_configured?
+      Gitlab::Geo.primary_node.present?
+    end
+
     def self.license_allows?
       ::License.feature_available?(:geo)
     end

lib/gitlab/geo/base_request.rb

@@ -9,6 +9,7 @@ module Gitlab
         @request_data = request_data
       end
 
+      # Raises GeoNodeNotFoundError if current node is not a Geo node
       def headers
         {
           'Authorization' => geo_auth_token(request_data)
@@ -19,7 +20,7 @@ module Gitlab
 
       def geo_auth_token(message)
         geo_node = requesting_node
-        return unless geo_node
+        raise GeoNodeNotFoundError unless geo_node
 
         payload = { data: message.to_json, iat: Time.now.to_i }
         token = JWT.encode(payload, geo_node.secret_access_key, 'HS256')

spec/lib/gitlab/geo_spec.rb

@@ -43,6 +43,20 @@ describe Gitlab::Geo do
     end
   end
 
+  describe 'primary_node_configured?' do
+    context 'when current node is a primary node' do
+      it 'returns true' do
+        primary_node
+
+        expect(described_class.primary_node_configured?).to be_truthy
+      end
+
+      it 'returns false when primary does not exist' do
+        expect(described_class.primary_node_configured?).to be_falsey
+      end
+    end
+  end
+
   describe 'secondary?' do
     context 'when current node is a secondary node' do
       before do

spec/services/geo/node_status_service_spec.rb

@@ -83,5 +83,13 @@ describe Geo::NodeStatusService do
 
       expect(status.health).to eq('Error decrypting the Geo secret from the database. Check that the primary uses the correct db_key_base.')
     end
+
+    it 'gracefully handles case when primary is deleted' do
+      primary.destroy
+
+      status = subject.call(secondary)
+
+      expect(status.health).to eq('This GitLab instance does not appear to be configured properly as a Geo node. Make sure the URLs are using the correct fully-qualified domain names.')
+    end
   end
 end