41 lines
1.6 KiB
Markdown
41 lines
1.6 KiB
Markdown
# A simple Kubernetes load balancer
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Configures nginx to forward connections to your node IPs.
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Services should be declared as NodePort, which means that they
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open a port on all nodes. When the request lands on any node,
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it is forwarded to the correct pod via the network mesh kubernetes
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is using. In theory, there is one a hop penalty.
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But lets be honest. You're running with a single LB, probably a GCE free
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tier N1 VM. That extra hop doesn't matter.
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## Config
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Configure nginx to do what you want, test it. Use any Node IP for your testing.
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This will become the 'template_dir' in the argument to the LB.
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Move that directory to somewhere new, i.e. `/etc/nginx-template/`. Make
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a symlink from that new directory to the old one (i.e.,
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`ln -s /etc/nginx-template /etc/nginx/`).
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Make a workspace directory for this tool; it will write configs to this folder
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before updating the symlink you created above. It needs to be persistent so on
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server reboot the service starts ok (i.e., `mkdir /var/skubelb/`).
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Make sure the user running the tool has read access to the template folder, read-write
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access to the workspace folder and config symlink.
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Run the server with a command like:
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```sh
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skubelb --needle some_node_ip \
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--workspace_dir /var/skubelb \
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--config_symlink /etc/nginx \
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--template_dir /etc/nginx-template
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--listen 0.0.0.0:8080
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```
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Replacing `some_node_ip` with the node IP you used during the initial setup.
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Next, configure the Kubernetes nodes to POST `http://loadbalancer:8080/register` when
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they started, and DELETE `http://loadbalancer:8080/register` when they shutdown. |