# VPP Containerlab Docker image

This docker container creates a VPP instance based on the latest VPP release. It starts up as per
normal, using /etc/vpp/startup.conf (which Containerlab might replace when it starts its
containers). Once started, it'll execute /etc/vpp/bootstrap.vpp within the dataplane. There are
three relevant files:

1.   `manual-pre.vpp` -- can be supplied by the user, to run any configuration statements before
     containerlab takes control.

1.   `clab.vpp` -- generated by `files/container-init.sh`. Its purpose is to bind the `veth`
     interfaces that containerlab has added to the container into the VPP dataplane (see below).

1.   `manual-post.vpp` -- can be supplied by the user, to run any configuration statements after
     containerlab is finished with its per-lab statements.

## Building

```bash
IMG=git.ipng.ch/ipng/vpp-containerlab
TAG=latest
docker build --no-cache -f Dockerfile.bookworm -t $IMG .
docker image tag $IMG $IMG:$TAG
docker push $IMG
docker push $IMG:$TAG
```

## Testing the container standalone

```bash
docker network create --driver=bridge clab-network --subnet=192.0.2.0/24 \
                      --ipv6 --subnet=2001:db8::/64
docker rm clab-pim 
docker run --cap-add=NET_ADMIN --cap-add=SYS_NICE --cap-add=SYS_PTRACE \
           --device=/dev/net/tun:/dev/net/tun \
           --device=/dev/vhost-net:/dev/vhost-net \
           --privileged --name clab-pim \
           docker.io/pimvanpelt/vpp-containerlab:latest
docker network connect clab-network clab-pim
```

### A note on DPDK

DPDK will be disabled by default as it requires hugepages and VFIO and/or UIO to use physical
network cards. If DPDK at some future point is desired, mapping VFIO can be done by adding this:
```
           --device=/dev/vfio/vfio:/dev/vfio/vfio
```

or in Containerlab, using the `devices` feature:

```
my-node:
  image: vpp-containerlab:latest
  kind: vpp
  devices:
    - /dev/vfio/vfio
    - /dev/net/tun
    - /dev/vhost-net
```

If using DPDK in a container, one of the userspace IO kernel drivers must be loaded in the host
kernel. Options are `igb_uio`, `vfio_pci`, or `uio_pci_generic`:

```bash
$ sudo modprobe igb_uio
$ sudo modprobe vfio_pci
$ sudo modprobe uio_pci_generic
```

Particularly the VFIO driver needs to be present before one can attempt to bindmount
`/dev/vfio/vfio` into the container!

## Configuring VPP

When Containerlab starts the docker containers, it'll offer one or more `veth` point to point
network links, which will show up as `eth1` and further. `eth0` is the default NIC that belongs to
the management plane in Containerlab (the one which you'll see with `containerlab inspect`). Before
VPP can use these `veth` interfaces, it needs to bind them, like so:

```
docker exec -it clab-pim vppctl
```

and then within the VPP control shell:

```
create host-interface v2 name eth1
set interface name host-eth1 eth1
set interface mtu 1500 eth1
set interface ip address eth1 192.0.2.2/24
set interface ip address eth1 2001:db8::2/64
set interface state eth1 up
```

Containerlab will attach these `veth` pairs to the container, and replace our Docker CMD with one
that waits for all of these interfaces to be added (typically called `if-wait.sh`). In our own CMD,
we then generate a config file called `/etc/vpp/clab.vpp` which contains the necessary VPP commands
to take control over these `veth` pairs.

In addition, you can add more commands that'll execute on startup by copying in
`/etc/vpp/manual-pre.vpp` (to be executed _before_ the containerlab stuff) or
`/etc/vpp/manual-post.vpp` (to be executed _after_ the containerlab stuff).