in OpenNebula 5.8.1 sunstone does not start without an IPv4 address

[telmich]

Description
Previously it was possible to start sunstone without having an IPv4 address on the system.

To Reproduce
Setup a host that only has IPv4 on localhost like this:

root@devuan:/etc/one# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 02:00:f0:a9:c3:fa brd ff:ff:ff:ff:ff:ff
    inet6 2a0a:e5c0:2:12:0:f0ff:fea9:c3fa/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::f0ff:fea9:c3fa/64 scope link 
       valid_lft forever preferred_lft forever

The result is as follows:

/var/lib/gems/2.3.0/gems/eventmachine-1.2.7/lib/eventmachine.rb:532:in `start_tcp_server': no acceptor (port is in use or requires root privileges) (RuntimeError)
	from /var/lib/gems/2.3.0/gems/eventmachine-1.2.7/lib/eventmachine.rb:532:in `start_server'
	from /var/lib/gems/2.3.0/gems/thin-1.7.2/lib/thin/backends/tcp_server.rb:17:in `connect'
	from /var/lib/gems/2.3.0/gems/thin-1.7.2/lib/thin/backends/base.rb:63:in `block in start'
	from /var/lib/gems/2.3.0/gems/eventmachine-1.2.7/lib/eventmachine.rb:195:in `run_machine'
	from /var/lib/gems/2.3.0/gems/eventmachine-1.2.7/lib/eventmachine.rb:195:in `run'
	from /var/lib/gems/2.3.0/gems/thin-1.7.2/lib/thin/backends/base.rb:73:in `start'
	from /var/lib/gems/2.3.0/gems/thin-1.7.2/lib/thin/server.rb:162:in `start'
	from /var/lib/gems/2.3.0/gems/rack-2.0.6/lib/rack/handler/thin.rb:22:in `run'
	from /var/lib/gems/2.3.0/gems/sinatra-2.0.5/lib/sinatra/base.rb:1525:in `start_server'
	from /var/lib/gems/2.3.0/gems/sinatra-2.0.5/lib/sinatra/base.rb:1459:in `run!'
	from /usr/lib/one/sunstone/sunstone-server.rb:898:in `<main>'

If I add a random IPv4 address to eth0, it starts:

root@devuan:/etc/one# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 02:00:f0:a9:c3:fa brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.5/24 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2a0a:e5c0:2:12:0:f0ff:fea9:c3fa/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::f0ff:fea9:c3fa/64 scope link 
       valid_lft forever preferred_lft forever
root@devuan:/etc/one# 

Expected behavior
Sunstone can be started on IPv6 only systems.
Even if IPv4 only bindings work, listening on localhost, as defined in the configuration, should work:

root@devuan:/etc/one# grep -e :host -e :port /etc/one/sunstone-server.conf
:host: 127.0.0.1
:port: 9869

Even better / really correct behaviour would be if :host can actually be "[::1]"

Details

• Affected Component: Sunstone
• Hypervisor: any
• Version: 5.8.1

Additional context

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[al3xhh]

Hello @telmich

I have done some tests and for it's working if I use the IPV6 address as a host in the sunstone-server.conf, could you try this way and tell me if it works for you?

$ grep -e :host -e :port /etc/one/sunstone-server.conf
:host: 2a0a:e5c0:2:12:0:f0ff:fea9:c3fa 
:port: 9869

$ ss -tanp -6
State      Recv-Q Send-Q Local Address:Port               Peer Address:Port              
LISTEN     0      128     2a0a:e5c0:2:12:0:f0ff:fea9:c3fa:9869                     :::*                   users:(("ruby",pid=2392,fd=11))

[telmich]

That is correct, 2a0a:e5c0:2:12:0:f0ff:fea9:c3fa as :host: works. However ::1, binding to IPv6 localhost does not work. If I add :host: ::1 then I get the following behaviour:

root@devuan:/etc/one# netstat -anp | grep ruby
tcp        0      0 0.0.0.0:9869            0.0.0.0:*               LISTEN      26283/ruby          

So take away:

• I used the wrong format: [..] based
• Using the right format (literal IPv6) with extended ipv6 address / GUA works
• Binding to IPv6 localhost using ::1 does not work

[al3xhh]

Hello @telmich

I did more tests and it worked in these scenarios:

$ grep -e :host -e :port /etc/one/sunstone-server.conf
:host: 0::1
:port: 9869

ss -tanp -6
State       Recv-Q Send-Q                        Local Address:Port                                       Peer Address:Port              
LISTEN      0      100                                     ::1:9869

$ grep -e :host -e :port /etc/one/sunstone-server.conf
:host: 0::0
:port: 9869

ss -tanp -6
State       Recv-Q Send-Q                        Local Address:Port                                       Peer Address:Port              
LISTEN      0      100                                     :::9869

We will add a note in the documentation.

[al3xhh]

Closing this.

[telmich]

@al3xhh It's good to know it works, but using 0::1 or 0::0 are really counterintuitive for anyone using IPv6 and I'd also say it contradicts all IPv6 RFCs out there.

[al3xhh]

@telmich this is a workaround for the ruby gems we use in Sunstone, it's not related directly with our code.

[telmich]

Ohhh, I understand. Can you point me to that gem? I'll open a bug report there.

[al3xhh]

@telmich I have done more tests. You can use :: if you are using sunstone + apache. So the problem would be in thin gem, but I'm not sure where do you have to open the issue.

[telmich]

@al3xhh Not sure if I understand "sunstone + apache" - is there an apache module for sunstone? We are running a couple of different ruby on rails projects that use unicorn and as far as I remember that works also with ::.

[al3xhh]

You can run sunstone behind apache server, see this.