I'm trying to dockerize a rails 7 app using the default puma server with ssl enabled using a self-signed cert. Launching the app natively works as expected.

When running as a container, I get a 'PR_END_OF_FILE_ERROR' error in Firefox. Testing with other browsers results in 'This site can'be reached. localhost unexepectedly closed the connection'.

docker run command: docker run --rm -it -p 3000:3000 my-app-image

Dockerfile CMD: CMD [ "rails", "s" ]

Troubleshooting steps:

1. Machine reboot

2. Update Docker

3. Map host port 443 to container port 3000

4. $RAILS_ENV both as development and production

5. Variations of rails command in docker file:

   1. CMD [ "bundle", "exec", "rails", "s", "-b", "0.0.0.0" ]
   2. CMD [ "rails", "s", "-b", "127.0.0.1" ]
   3. CMD [ "rails", "s", "-u", "puma", "-b", "'ssl://127.0.0.1/?key=server.key&cert=server.crt&verify_mode=none'" ]

config/application.rb

...
# Enable SSL
config.force_ssl = true
...

config/puma.rb

...
environment ENV.fetch("RAILS_ENV") { "development" }

# SSL Configuration
localhost_key = 'server.key'
localhost_crt = 'server.crt'

ssl_bind 'localhost', 3000, {
  key: localhost_key,
  cert: localhost_crt,
  verify_mode: 'none'
}
...

Since it works when run natively, I think the issue lies with either docker or puma, but I'm not sure what it could be or how to troubleshoot further.

CodePudding user response：

The issue was binding the ssl port in the puma.rb config file to localhost, which isn't available outside of the running container.

Changing:

ssl_bind 'localhost', 3000, {

To:

ssl_bind '0.0.0.0', 3000, {

resolved the issue.