Quick read of ipv6 docs and small fixes.

[ypid]

• Why on earth does one directly edit the systemd/system/docker.service
  file just to add a start argument?
• Fixed typos.
• I have not fully tested it yet, but I will when I have time.

[kylemanna]

If using systemd, people need to use systemctl. Ubuntu provides service binary to manage upstart services and maybe will soon wrap systemd interface.

Probably need service and systemctl commands for upstart and systemd respectively.

[kylemanna]

Thanks for reviewing!

I don't understand your comment about modifying the systemd service for two reasons:

1. People shouldn't be modifying the service file directly. It should be overriden as described in the init file. I'm currently running several OpenVPN servers on one of my servers and it works. The goal is to make the systemd service extensible and have sensible defaults. Open to other suggestions.

   The IPv6 stuff in the service file is an eye sore, but Docker doesn't handle network configuration very well at this point.

2. Why are you using the start argument? Are you storing the state in a single container? Running a single container makes it very hard to update. My philosophy is to do a docker pull to always pull the latest openvpn image (and fail gracefully if the pull fails) to get the latest security updates and then create a new container with docker run. If you're doing docker start ... it suggests you're re-using a container, why?

[ypid]

Hi

Not sure if I understand you correctly.

My main confusion was about the sed -e 's:^\(ExecStart.*\):\1 --ipv6:' /lib/systemd/system/docker.service | tee /etc/systemd/system/docker.service line which you used to append the --ipv6 switch. This can be done much simpler and more robust using the /etc/default/docker file. (Wrote an Ansible Role for that 😄 ypid.docker)

About the systemctl restart vs. service command I guess they are interchangeble on most systems running systemd (which is the majority of current distributions). I am just used to the service command because it is shorter 😄 (reverted …).

To 2. Not sure what you mean. I published parts of my Docker setup configuration on GitHub. Here is the relevant part.

BTW. Thanks for your work on v6 integration!

[kylemanna]

Still need to tell systemd to examine the updated docker.service file, so the daemon-reload is necessary.

[ypid]

v6 is now configured in /etc/default/docker which is read on normal service restart. There should be no need to restart systemd itself for that.

For Step 3 — Setup the systemd Unit File, it is a good idea, but for adding a start augment, no.

[kylemanna]

Ahh. I was thinking of [email protected] and you're talking about docker.service.

The /etc/default configuration directory is Debian (and derivative) specific thing, as is service. These will hopefully go away when people finally standardize an init system across distributions. Systemd defines all these things in a much more extensible way.

In short, we need both until the Debian way dies (as it has already moved ot systemd) and Ubuntu will soon follow. Fedora and Arch has been on systemd for years.