Fix sidekiq web

* add rack-session gem (needed by rack 3)
* update standalone code from https://github.com/sidekiq/sidekiq/wiki/Monitoring#standalone
* fix sidekiq_web service in docker-compose.yml

Gemfile

@@ -20,6 +20,7 @@ gem "sequel"
 gem "thor"
 gem "zinzout"
 gem "puma"
+gem "rack-session"
 gem "sidekiq"
 gem "sidekiq-batch", git: "https://github.com/breamware/sidekiq-batch"
 

Gemfile.lock

@@ -101,6 +101,8 @@ GEM
       nio4r (~> 2.0)
     racc (1.8.0)
     rack (3.0.11)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
     rainbow (3.1.1)
     rdoc (6.6.3.1)
       psych (>= 4.0.0)
@@ -212,6 +214,7 @@ DEPENDENCIES
   pry
   puma
   push_metrics!
+  rack-session
   rgl
   rspec
   rspec-sidekiq

bin/sidekiq_web.ru

@@ -1,18 +1,14 @@
-require "sidekiq"
-require "sidekiq/web"
-require_relative "../config/initializers/sidekiq"
-
-SESSION_KEY = ".session.key"
-
-if !File.exist?(SESSION_KEY)
-  require "securerandom"
-  File.open(SESSION_KEY, "w") do |f|
-    f.write(SecureRandom.hex(32))
-  end
-end
+# This is sidekiq_web.ru
+# Run with `bundle exec rackup sidekiq_web.ru` or similar.
 
-Services.redis_config[:size] = 1
-
-use Rack::Session::Cookie, secret: File.read(SESSION_KEY), same_site: true, max_age: 86400
+require "securerandom"
+require "rack/session"
+require "sidekiq/web"
 
+# In a multi-process deployment, all Web UI instances should share
+# this secret key so they can all decode the encrypted browser cookies
+# and provide a working session.
+# Rails does this in /config/initializers/secret_token.rb
+secret_key = SecureRandom.hex(32)
+use Rack::Session::Cookie, secret: secret_key, same_site: true, max_age: 86400
 run Sidekiq::Web

docker-compose.yml

@@ -49,6 +49,8 @@ services:
     <<: *holdings-container-defaults
     restart: always
     volumes:
+      - .:/usr/src/app
+      - gem_cache:/gems
       - ./example/datasets:/tmp/datasets
     command: bundle exec sidekiq -c 1 -r ./lib/sidekiq_jobs.rb