# VPP Containerlab Docker image

## User Documentation

The file `vpp.clab.yml` contains an example topology existing of two VPP instances connected each to
one Alpine linux container, in the following topology:

![learn-vpp](learn-vpp.png)

This container ships with both Bird2 and FRRouting as controlplane agents.

You can deploy:
*   Bird2: `containerlab deploy --topo vpp-bird.clab.yml`.
*   FRR: `containerlab deploy --topo vpp-frr.clab.yml`.

three relevant files for VPP are included in this repository:
1.   `config/vpp*/vppcfg.yaml` configures the dataplane interfaces, including a loopback address.
1.   `config/vpp*/bird-local.conf` configures the controlplane to enable BFD and OSPF.
1.   `config/vpp*/frr.conf` configures the controlplane to enable BFD and OSPF.

Once the lab comes up, you can SSH to the VPP containers (`vpp1` and `vpp2`) which will have your
SSH keys installed (if available). Otherwise, you can log in as user `root` using password `vpp`.

VPP runs its own network namespace called `dataplane`, which is very similar to SR Linux default
`network-instance`. You can join it to take a look:

```bash
pim@summer:~/src/vpp-containerlab$ ssh root@vpp1
root@vpp1:~# nsenter --net=/var/run/netns/dataplane
root@vpp1:~# ip -br a
lo               DOWN           
loop0            UP             10.82.98.0/32 2001:db8:8298::/128 fe80::dcad:ff:fe00:0/64 
eth1             UNKNOWN        10.82.98.65/28 2001:db8:8298:101::1/64 fe80::a8c1:abff:fe77:acb9/64 
eth2             UNKNOWN        10.82.98.16/31 2001:db8:8298:1::1/64 fe80::a8c1:abff:fef0:7125/64 

root@vpp1:~# ping 10.82.98.1 ## The vpp2 IPv4 loopback address
PING 10.82.98.1 (10.82.98.1) 56(84) bytes of data.
64 bytes from 10.82.98.1: icmp_seq=1 ttl=64 time=9.53 ms
64 bytes from 10.82.98.1: icmp_seq=2 ttl=64 time=15.9 ms
^C
--- 10.82.98.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 9.530/12.735/15.941/3.205 ms
```

The two clients are running a minimalistic Alpine Linux container, which doesn't ship with SSH by
default. You can enter the containers as following:

```bash
pim@summer:~/src/vpp-containerlab$ docker exec -it client1 sh
/ # ip addr show dev eth1
531235: eth1@if531234: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 9500 qdisc noqueue state UP 
    link/ether 00:c1:ab:00:00:01 brd ff:ff:ff:ff:ff:ff
    inet 10.82.98.66/28 scope global eth1
       valid_lft forever preferred_lft forever
    inet6 2001:db8:8298:101::2/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::2c1:abff:fe00:1/64 scope link 
       valid_lft forever preferred_lft forever
/ # traceroute 10.82.98.82
traceroute to 10.82.98.82 (10.82.98.82), 30 hops max, 46 byte packets
 1  10.82.98.65 (10.82.98.65)  5.906 ms  7.086 ms  7.868 ms
 2  10.82.98.17 (10.82.98.17)  24.007 ms  23.349 ms  15.933 ms
 3  10.82.98.82 (10.82.98.82)  39.978 ms  31.127 ms  31.854 ms

/ # traceroute 2001:db8:8298:102::2
traceroute to 2001:db8:8298:102::2 (2001:db8:8298:102::2), 30 hops max, 72 byte packets
 1  2001:db8:8298:101::1 (2001:db8:8298:101::1)  0.701 ms  7.144 ms  7.900 ms
 2  2001:db8:8298:1::2 (2001:db8:8298:1::2)  23.909 ms  22.943 ms  23.893 ms
 3  2001:db8:8298:102::2 (2001:db8:8298:102::2)  31.964 ms  30.814 ms  32.000 ms
```

From the vantage point of `client1`, the first hop represents the `vpp1` node, which forwards to
`vpp2`, which finally forwards to `client2`.

## Developer Documentation

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
two relevant files:

1.   `clab.vpp` -- generated by `files/init-container.sh`. Its purpose is to bind the `veth`
     interfaces that containerlab has added to the container into the VPP dataplane (see below).
1.   `vppcfg.vpp` -- generated by `files/init-container.sh`. Its purpose is to read the user
     specified `vppcfg.yaml` file and convert it into VPP CLI commands. If no YAML file is
     specified, or if it is not syntactically valid, an empty file is generated instead.

For Containerlab users who wish to have more control over their VPP bootstrap, it's possible to
bind-mount `/etc/vpp/bootstrap.vpp`.

### Building

To build, this container uses Docker's `buildx`, for which on Debian Bookworm it's required to use
the upstream (docker.com) packages described [[here](https://docs.docker.com/engine/install/debian/)].
To allow the buildx to build for multi-arch, it's also required to install the Qemu `binfmt`
emulators, with:

```bash
docker run --privileged --rm tonistiigi/binfmt --install all
```

Then, ongoing builds can be cross-platform and take about 1500 seconds on an AMD64 i7-12700T
The buildx invocation will build 'latest' and then tag it with the current VPP package release,
which you can get from `vppcfg show version`, like so:

```bash
IMG=git.ipng.ch/ipng/vpp-containerlab
ARCH=linux/$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/')
TAG=latest
docker buildx build --load --platform $ARCH \
  --tag $IMG:$TAG -f docker/Dockerfile docker/

TAG=v25.10-release
docker buildx build --load --build-arg REPO=2510 --platform $ARCH \
  --tag $IMG:$TAG -f docker/Dockerfile docker/
```

#### Sideloading locally built VPP packages

Instead of pulling VPP from packagecloud, you can sideload locally built `.deb` packages using
Docker buildx's `--build-context` flag. This is useful for testing unreleased VPP builds or
working around version-specific issues (for example, VPP 25.10 fails to start on kernels that
do not expose NUMA topology via sysfs, such as OrbStack on Apple Silicon; VPP 26.06+ fixes this).

Point `--build-context vppdebs=<path>` at a directory containing `libvppinfra_*.deb`,
`vpp_*.deb`, and `vpp-plugin-core_*.deb`. If the context is not provided, the build falls back
to packagecloud as normal. The `.deb` files are bind-mounted during the build and never stored
in an image layer. **Note:** the directory must contain `.deb` files for exactly one VPP version;
if multiple versions are present the glob patterns will match ambiguously and the build will fail.

```bash
# Build from locally compiled VPP packages (e.g. from ~/src/vpp after make pkg-deb):
IMG=git.ipng.ch/ipng/vpp-containerlab
ARCH=linux/$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/')
VPPDEBS=~/src/vpp/build-root
docker buildx build --load --platform $ARCH \
  --build-context vppdebs=$VPPDEBS \
  --tag $IMG:latest -f docker/Dockerfile docker/

# Build from packagecloud as normal (no --build-context needed):
docker buildx build --load --platform $ARCH \
  --tag $IMG:latest -f docker/Dockerfile docker/
```

### Multiarch

Building a combined `linux/amd64` + `linux/arm64` manifest requires two machines building natively
— one per architecture. The setup below uses `summer` (amd64, Linux) and `jessica` (arm64, macOS
running OrbStack). **VPP must be compiled on each machine before building the Docker image**, because
the sideloader mounts locally built `.deb` files that are architecture-specific.

#### Setup

On `jessica`, the Docker daemon runs inside OrbStack's Linux VM. Expose its SSH port so `summer`
can reach it. OrbStack listens on `127.0.0.1:32222`; add a jump-host entry to `~/.ssh/config` on
`summer`:

```
Host jessica-orb
    HostName 127.0.0.1
    Port 32222
    User pim
    ProxyCommand ssh jessica -W 127.0.0.1:32222
    IdentityFile ~/.ssh/jessica-orb-key
    IdentitiesOnly yes
    UserKnownHostsFile /dev/null
    StrictHostKeyChecking no
```

Copy OrbStack's SSH key from `jessica` to `summer`:

```bash
scp jessica:~/.orbstack/ssh/id_ed25519 ~/.ssh/jessica-orb-key
chmod 600 ~/.ssh/jessica-orb-key
```

Verify the full chain works:

```bash
ssh jessica-orb 'uname -m && docker info | head -3'
# expected: aarch64
```

Create the multiarch builder (run once on `summer`):

```bash
docker buildx create --name multiarch --driver docker-container --platform linux/amd64 --node summer-amd64
docker buildx create --append --name multiarch --driver docker-container --platform linux/arm64 --node jessica-arm64 ssh://jessica-orb
docker buildx inspect multiarch --bootstrap
```

#### Build

Build VPP on both machines first (`make pkg-deb` in your VPP source tree on both `summer` and the
OrbStack VM on `jessica`). When sideloading `.deb` files, Docker sends the build context from the
client to every builder node — meaning `summer`'s amd64 debs would be sent to `jessica-orb` for
the arm64 build (wrong arch). The solution is to build each platform separately on its native
machine and combine them into a manifest.

```bash
IMG=git.ipng.ch/ipng/vpp-containerlab
VPPDEBS=~/src/vpp/build-root

# Step 1: build amd64 on summer, push with platform tag
docker buildx build --platform linux/amd64 \
  --build-context vppdebs=$VPPDEBS \
  --push --tag $IMG:latest-amd64 \
  -f docker/Dockerfile docker/

# Step 2: build arm64 natively on jessica-orb, push with platform tag
#   (repo and VPP debs must be present on jessica-orb at the same paths)
ssh jessica-orb "cd ~/src/vpp-containerlab && \
  docker buildx build --platform linux/arm64 \
    --build-context vppdebs=$VPPDEBS \
    --push --tag $IMG:latest-arm64 \
    -f docker/Dockerfile docker/"

# Step 3: combine into a single multi-arch manifest and push in one step
# (docker buildx build --push produces manifest lists, so use imagetools, not docker manifest)
docker buildx imagetools create \
  --tag $IMG:latest \
  $IMG:latest-amd64 \
  $IMG:latest-arm64
```

### Testing standalone container

```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 \
           git.ipng.ch/ipng/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:

```yaml
my-node:
  image: git.ipng.ch/ipng/vpp-containerlab:latest
  kind: fdio_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:

```bash
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.