Configure Apache and Passenger to use websocket

Question

I'm trying to setup apache to use ruby on rails web socket with passenger. I know that Action Cable is not supported on Passenger + Apache, so I'm tryng to use the reverse proxy solution: https://www.phusionpassenger.com/library/deploy/standalone/reverse_proxy.html

The main application should continue to use the Passenger Apache module while the websocket should use passenger standalone.

I enabled the reverse proxy and changed the vhost config.

<VirtualHost *:80>
...

 PassengerRuby /home/rails/.rvm/gems/ruby-2.5.1/wrappers/ruby

  <Location "/cable">
     ProxyPass "ws://127.0.0.1:4000/cable"
     ProxyPassReverse http://127.0.0.1:4000/
     ProxyPreserveHost on
  </Location>

...
</VirtualHost>

When I start the passenger from the command line

bundle exec passenger start --daemonize --address 127.0.0.1 --port 4000

it works fine, but when I create a service using systemd in Ubuntu 18.04.5 LTS

...
[Service]
Type=forking
WorkingDirectory=/mnt/xfeature/srv/www/f3.xxxx.xxx/current
Environment=RAILS_ENV=feature

User=rails
Group=www-data
UMask=0002
ExecStart=/home/rails/.rvm/bin/rvm-shell -c 'bundle exec passenger start --daemonize -e feature --address 127.0.0.1 --port 4000 --log-level 5'
ExecStop=/home/rails/.rvm/bin/rvm-shell -c 'bundle exec passenger stop --port 4000'

....

it fails usually with this error.

[ E 2021-05-13 09:52:13.3607 21447/Tz age/Cor/App/Implementation.cpp:221 ]: Could not spawn process for application /mnt/xfeature/srv/www/f3.xxx.xxx/releases/20210513094622: An operating system error occurred while preparing to start a preloader process: Cannot change the directory '/tmp/passenger.spawn.XXXXgMx55z/envdump' its UID to 1001 and GID to 1001: Operation not permitted (errno=1)
  Error ID: 847da63a
  Error details saved to: /tmp/passenger-error-5S5Syq.html

and the websocket connection cannot be established. I checked the /tmp permission and are OK.

Any suggestion?

curtp curtp · Accepted Answer · 2021-07-28T18:34:57

We had some strange issues with Apache and Passenger recently. It turns out Apache automatically updated and changed the PrivateTmp setting to true, which caused a similar error message.

I'm not sure if that is what is causing your error, but you could check that to verify that PrivateTmp is set to false.

Our configuration is:

/etc/systemd/system/apache2.service.d/override.conf

override.conf Contents:

PrivateTmp=false

I'm not certain how that override.conf file is loaded. I assume there is a configuration somewhere looking for an override file and it is using it.

Configure Apache and Passenger to use websocket

1 Answers