Rails 6 Production ActionCable Error during WebSocket handshake - ruby-on-rails

Question

WebSocket connection to 'ws://my-ec2/cable' failed:
Error during WebSocket handshake: Unexpected response code: 404
Guys, I saw this (old) issue a lot here, so it may seem like it is duplicated. But in my case, I try very hard to fix this error but I can't.
I also follow this correction: https://stackoverflow.com/a/55715218/8478892 but no success.
My nginx.conf:
upstream puma {
server unix:///home/ubuntu/apps/my_app/shared/tmp/sockets/my_app-puma.sock;
}
server {
listen 80 default_server deferred;
# If you're planning on using SSL (which you should), you can also go ahead and fill out the following server_name variable:
# server_name example.com;
# Don't forget to update these, too
root /home/ubuntu/apps/my_app/current/public;
access_log /var/log/nginx/nginx.access.log;
error_log /var/log/nginx/nginx.error.log info;
location ^~ /assets/ {
gzip_static on;
expires max;
add_header Cache-Control public;
}
try_files $uri/index.html $uri #puma;
location #puma {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://puma;
}
location /cable {
proxy_pass http://puma;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header Host $host;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass_request_headers on;
proxy_buffering off;
proxy_redirect off;
break;
}
error_page 500 502 503 504 /500.html;
client_max_body_size 10M;
keepalive_timeout 10;
}
And in my cable.yml:
production:
url: redis://http://my-ec2.com:6379
local: &local
url: redis://localhost:6379
development: *local
test: *local
And my environments/production.rb:
Rails.application.configure do
config.cache_classes = true
config.eager_load = true
config.consider_all_requests_local = false
config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
config.active_storage.service = :local
config.action_cable.mount_path = '/cable'
config.action_cable.url = 'ws://my-ec2/cable'
config.action_cable.allow_same_origin_as_host = true
config.action_cable.allowed_request_origins = ["*"]
config.log_level = :debug
config.log_tags = [ :request_id ]
config.action_mailer.perform_caching = false
config.i18n.fallbacks = true
config.active_support.deprecation = :notify
config.log_formatter = ::Logger::Formatter.new
if ENV["RAILS_LOG_TO_STDOUT"].present?
logger = ActiveSupport::Logger.new(STDOUT)
logger.formatter = config.log_formatter
config.logger = ActiveSupport::TaggedLogging.new(logger)
end
config.active_record.dump_schema_after_migration = false
end
Thought of the day for those who are having this problem:
Setting up ActionCable en localhost had already been a good fight, but setting up in production is an entire war.

Answer 1

Do you have redis installed on your machine or is it a docker container? I think you are using it with sidekiq, and do you have any sidekiq/redis initializer file under /config/initializers?
In cable.yml it should be
production:
url: redis://redis:6379/0

Answer 2

After a few days, I managed to solve this problem myself.
The main reason for my error is that in my environments / production.rb file, I was saying that the actioncable endpoint was the public ip of my ec2. But in reality you should put localhost. I used the same configuration I have in development.rb:
production.rb before:
...
config.action_cable.mount_path = '/cable'
config.action_cable.url = 'ws://my_ec2/cable'
config.action_cable.allow_same_origin_as_host = true
config.action_cable.allowed_request_origins = ["*"]
...
production.rb after:
...
config.action_cable.disable_request_forgery_protection = true
config.action_cable.url = "ws://localhost:3000/cable"
config.action_cable.allowed_request_origins = [/http:\/\/*/, /https:\/\/*/]
config.action_cable.allowed_request_origins = /(\.dev$)|^localhost$/
...