# net-service-controller

**Repository Path**: mirrors_k8snetworkplumbingwg/net-service-controller

## Basic Information

- **Project Name**: net-service-controller
- **Description**: Network service controller (Multus compatible)
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-11-24
- **Last Updated**: 2026-04-26

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# NetworkService controller

This is a Multus aware service controller, allowing the creation of headless
services on Multus additional networks.

*This is not production quality - it works, but is only demo / POC quality. It
is likely that it will evolve into something better, but it is work in
progress.*

## Build

*You do not need to build the project unless you want to change the code.*

This project uses the operator-sdk, which you must have installed
locally. Build instructions are contained [here](docs/build.md).

## Installation

Install as follows (after building and pushing if you have changed the code).

    kubectl apply -f manifest/install

## Usage

Sample `NetService` objects are contained in the [manifests](manifests)
directory, together with a sample multi-network deployment
([manifests/multi.yaml](manifests/multi.yaml)). These assume networks named
`core` and `access` have been created and multus is installed in the cluster.

. Each such object has the following fields.

- The name of the `NetService` object is the name of the resulting service that
  will be created.

- The `netAttachDef` field is the name of the network attachment definition to
  select on.

- The `selector` is the selector, with the same format as a normal service
  selector.

Upon creating your `NetService` object, a service with the same name will be
created, pulling the IPs from the corresponding network, and will be kept
updated as changes are made to pods.

## Design

Suppose the `NetService` object is called `example`. The operator creates three
things as dependencies of the `NetService` object.

- It creates a headless service called `example-template` with a selector as
  specified. This automatically leads the endpoints controller to create and
  populate an endpoints object, `example-template`.

- It creates a headless service called `example` with no selector.

- It creates an endpoints object called `example`. This endpoints object is
  kept up to date with the IPs of the correct network from the pods which
  appear in `example-template`.

## Limitations

There are some limitations.

- This isn't production quality and has had limited testing.

- The build process (install operator-sdk, copy in some files) should be
  cleaned up, although ideally without just checking in a load of autogenerated
  code.

- It only supports headless services. It could clearly be extended to other
  types, but since not all networks are routable from everywhere in general,
  adding cluster IP support requires some thought.

- Only IPv4 addresses are included, and only the first one for the network
  attachment definition (if any).

- The naming isn't right. 

    - The hardcoded `-template` in service names doesn't feel very robust. It
      should use a random suffix or a preconfigured suffix.

    - The `NetService` name for the custom resource is probably not right
      either.

    - The path to the resources ends with `metaswitch.com` - while originally
      created at Metaswitch, that is not the right longer term name.

- The annotation parsing code is frankly a hack, which should probably be
  replaced with use of the [standard
  client](https://github.com/k8snetworkplumbingwg/network-attachment-definition-client).

- There are a couple of other gotchas in the code tagged with `FIXME`.