skubelb/README.md

# A simple Kubernetes load balancer

Configures nginx to forward connections to your node IPs.
Services should be declared as NodePort, which means that they
open a port on all nodes. When the request lands on any node,
it is forwarded to the correct pod via the network mesh kubernetes
is using. In theory, there is one a hop penalty.

But lets be honest. You're running with a single LB, probably a GCE free
tier N1 VM. That extra hop doesn't matter.

## Config

Configure nginx to do what you want, test it. Use any Node IP for your testing.
This will become the 'template_dir' in the argument to the LB.

Move that directory to somewhere new, i.e. `/etc/nginx-template/`. Make
a symlink from that new directory to the old one (i.e.,
`ln -s /etc/nginx-template /etc/nginx/`).

Make a workspace directory for this tool; it will write configs to this folder
before updating the symlink you created above. It needs to be persistent so on
server reboot the service starts ok (i.e., `mkdir /var/skubelb/`).

Make sure the user running the tool has read access to the template folder, read-write
access to the workspace folder and config symlink.

Run the server with a command like:

```sh
skubelb --needle some_node_ip \
    --workspace_dir /var/skubelb \
    --config_symlink /etc/nginx \
    --template_dir /etc/nginx-template
    --listen 0.0.0.0:8080
```

Replacing `some_node_ip` with the node IP you used during the initial setup.

Next, configure the Kubernetes nodes to POST `http://loadbalancer:8080/register` when
they started, and DELETE `http://loadbalancer:8080/register` when they shutdown.