Add support for Open vSwitch GRE tunnel

[Bacto]

Hi,

The kernel supports Open vSwitch and VXLAN tunnels, as seen in the kernel_config (CONFIG_OPENVSWITCH and CONFIG_OPENVSWITCH_VXLAN).

Unfortunately, it doesn't support GRE tunnels.
It would be great to add it, by adding CONFIG_OPENVSWITCH_GRE to the kernel_config.

Thanks (and btw, thanks for boot2docker 👍!!)

[Bacto]

Here is an example to fully support Open vSwitch GRE tunnels :)

git clone https://github.com/boot2docker/boot2docker.git
cd boot2docker
git checkout tags/v17.10.0-ce
echo CONFIG_OPENVSWITCH_GRE=m >> kernel_config
echo CONFIG_NET_IPGRE=m >> kernel_config
echo CONFIG_NET_IPGRE_BROADCAST=y >> kernel_config

docker build -t boot2docker .
docker run --rm boot2docker > boot2docker.iso

[tianon]

Man, not sure how I missed this, sorry!

This seems roughly reasonable, but I'm really curious what you're wanting to use Open vSwitch together with boot2docker for? (If you even still are, given how long I've taken to get back to you! 😅)

Given the life-support-only status of boot2docker, I'm hoping adding something like this won't encourage folks to use it for bigger things than perhaps they should. 😅