Unable to start rails on port 80

Question

I am trying to learn Linux better but currently only have very limited experience - so please excuse my ignorance in this matter.

I am trying to start rails on port 80, and as another user by using

sudo -u [user_name] bundle exec rails s --port=80 -e production

but this is failing with

eventmachine.rb:572:in 'start_tcp_server': no acceptor (RuntimeError)

Running sudo netstat -anltp|grep :80 shows that port 80 is not open\listening.

I have tried the following, with limited success:

sudo bundle exec rails s --port=80 -e production works in starting the server on port 80, but not as the user I want,

sudo -u [user_name] bundle exec rails s -e production works in starting the server as the correct user, but not on the desired port.

I have temporarily set the user to be in the Administrators group as I have read that its required for ports < 1024, but that hasn't seemed to help either.

What else can I try?

Answer 1

You can start services on ports <1024 with root user. The group (administrator in your case) has nothing to do with it.

There are a few things you can do though. For example:

• User iptables to redirect the ports (configurable with root rights).
• If the program allows it or you have access to the code: start as root, bind(), then drop privileges.
• There is a utility called authbind that is meant for such cases, but I personally have never used it, so I cannot comment on how well it works.
• Use setcap to add privilege to your program.