Add redis support

Gemfile

@@ -165,6 +165,7 @@ group :production do
   # we use dalli as standard memcache client
   # requires memcached 1.4+
   gem 'dalli', '~> 3.2.0'
+  gem 'redis', '~> 5.0.8'
 end
 
 gem 'i18n-js', '~> 4.2.3'

Gemfile.lock

@@ -375,6 +375,7 @@ GEM
     compare-xml (0.66)
       nokogiri (~> 1.8)
     concurrent-ruby (1.2.2)
+    connection_pool (2.4.1)
     cookiejar (0.3.3)
     crack (0.4.5)
       rexml
@@ -814,6 +815,10 @@ GEM
       psych (>= 4.0.0)
     recaptcha (5.16.0)
     redcarpet (3.6.0)
+    redis (5.0.8)
+      redis-client (>= 0.17.0)
+    redis-client (0.18.0)
+      connection_pool
     regexp_parser (2.8.2)
     reline (0.3.9)
       io-console (~> 0.5)
@@ -1151,6 +1156,7 @@ DEPENDENCIES
   rails-controller-testing (~> 1.0.2)
   rails-i18n (~> 7.0.0)
   rdoc (>= 2.4.2)
+  redis (~> 5.0.8)
   request_store (~> 1.5.0)
   responders (~> 3.0)
   retriable (~> 3.1.1)

config/constants/settings/definition.rb

@@ -209,7 +209,13 @@ module Settings
         description: 'The memcache server host and IP',
         format: :string,
         default: nil,
-        writable: false
+        writable: false,
+      },
+      cache_redis_url: {
+        description: 'URL to the redis cache server',
+        format: :string,
+        default: nil,
+        writable: false,
       },
       cache_namespace: {
         format: :string,
@@ -703,7 +709,7 @@ module Settings
         format: :symbol,
         default: :file_store,
         writable: false,
-        allowed: %i[file_store memcache]
+        allowed: %i[file_store memcache redis]
       },
       rails_relative_url_root: {
         description: 'Set a URL prefix / base path to run OpenProject under, e.g., host.tld/openproject',

docs/installation-and-operations/configuration/README.md

@@ -644,8 +644,13 @@ OPENPROJECT_SECURITY__BADGE__DISPLAYED="false"
 
 ### Cache configuration options
 
-* `rails_cache_store`: `memcache` for [memcached](https://www.memcached.org/) or `memory_store` (default: `file_store`)
-* `cache_memcache_server`: The memcache server host and IP (default: `nil`)
+* `rails_cache_store`: `memcache` for [memcached](https://www.memcached.org/), `redis` for [Redis cache](https://redis.io/), or `memory_store` (default: `file_store`)
+* When using `memcached`, the following configuration option is relevant:
+  * `cache_memcache_server`: The memcache server host and IP (default: `nil`)
+
+* When using `redis`, the following configuration option is relevant:
+  * `cache_redis_url`: The URL of the Redis host (e.g., `redis://host:6379`)
+
 * `cache_expires_in`: Expiration time for memcache entries (default: `nil`, no expiry)
 * `cache_namespace`: Namespace for cache keys, useful when multiple applications use a single memcache server (default: `nil`)
 

lib_static/open_project/configuration.rb

@@ -51,16 +51,18 @@ module OpenProject
         # Also use :mem_cache_store for when :dalli_store is configured
         cache_store = self['rails_cache_store'].try(:to_sym)
 
-        case cache_store
-        when :memcache, :dalli_store
-          cache_config = [:mem_cache_store]
-          cache_config << self['cache_memcache_server'] if self['cache_memcache_server']
-          # default to :file_store
-        when NilClass, :file_store
-          cache_config = [:file_store, Rails.root.join('tmp/cache')]
-        else
-          cache_config = [cache_store]
-        end
+        cache_config =
+          case cache_store
+          when :redis
+            redis_cache_configuration
+          when :memcache, :dalli_store
+            memcache_configuration
+            # default to :file_store
+          when NilClass, :file_store
+            [:file_store, Rails.root.join('tmp/cache')]
+          else
+            [cache_store]
+          end
 
         parameters = cache_store_parameters
         cache_config << parameters unless parameters.empty?
@@ -85,6 +87,27 @@ module OpenProject
 
       private
 
+      def memcache_configuration
+        cache_config = [:mem_cache_store]
+        cache_config << self['cache_memcache_server'] if self['cache_memcache_server']
+        cache_config
+      end
+
+      def redis_cache_configuration
+        url = self['cache_redis_url']
+        raise ArgumentError, "CACHE_SERVER is set to redis, but CACHE_REDIS_URL is not set." if url.blank?
+
+        [
+          :redis_cache_store,
+          {
+            url:,
+            error_handler: ->(method:, exception:) {
+              OpenProject.logger.error("Error in redis cache store #{method}: #{exception.message}", exception:)
+            }
+          }
+        ]
+      end
+
       def method_missing(name, *args, &)
         setting_name = name.to_s.sub(/\?$/, '')
 

spec/lib/open_project/configuration_spec.rb

@@ -74,6 +74,18 @@ RSpec.describe OpenProject::Configuration, :settings_reset do
           expect(subject.first).to eq(:file_store)
         end
       end
+
+      context 'setting rails cache to redis', with_config: { 'rails_cache_store' => 'redis' } do
+        context 'when setting the URL', with_config: { 'cache_redis_url' => 'redis://localhost:1234' } do
+          it 'sets the cache to :redis_cache_store' do
+            expect(subject.first).to eq(:redis_cache_store)
+          end
+        end
+
+        it 'raises an error trying to set redis without an URL' do
+          expect { subject }.to raise_error(ArgumentError, /CACHE_REDIS_URL is not set/)
+        end
+      end
     end
   end