VirtWeb/README.md

# VirtWEB
WIP project

## Development requirements
1. The `libvirt-dev` package must be installed:

```bash
sudo apt install libvirt-dev
```

2. Libvirt must also be installed:
```bash
sudo apt install qemu-kvm libvirt-daemon-system
```

3. Allow the current user to manage VMs:
```
sudo adduser $USER libvirt
sudo adduser $USER kvm 
```

> Note: You will need to login again for this change to take effect.


## Production requirements
### TODO
TODO

### Manual port forwarding without a LibVirt HOOK
* Allow ip forwarding in the kernel: edit `/etc/sysctl.conf` and uncomment the following line:

```
net.ipv4.ip_forward=1
```

* To reload `sysctl` without reboot:

```
sudo sysctl -p /etc/sysctl.conf
```

* Create the following IPTables rules:

```
UP_DEV=$(ip a | grep "192.168.1." -B 2 | head -n 1 | cut -d ':' -f 2 |
 tr -d ' ')
LOCAL_DEV=$(ip a | grep "192.168.25." -B 2 | head -n 1 | cut -d ':' -f 2 | tr -d ' ')
echo "$UP_DEV -> $LOCAL_DEV"

GUEST_IP=192.168.25.189
HOST_PORT=8085
GUEST_PORT=8085

# connections from outside
sudo iptables -I FORWARD -o $LOCAL_DEV -d  $GUEST_IP -j ACCEPT
sudo iptables -t nat -I PREROUTING -p tcp --dport $HOST_PORT -j DNAT --to $GUEST_IP:$GUEST_PORT
```

* Theses rules can be persisted using `iptables-save` then, or using a libvirt hook.


### Manual port forwarding with a LibVirt HOOK
* Allow ip forwarding in the kernel: edit `/etc/sysctl.conf` and uncomment the following line:

```
net.ipv4.ip_forward=1
```

* To reload `sysctl` without reboot:

```
sudo sysctl -p /etc/sysctl.conf
```

* Get the following information, using the web ui or `virsh`:
	* The name of the target guest
	* The IP and port of the guest who will receive the connection
	* The port of the host that will be forwarded to the guest

* Stop the guest if its running, either using `virsh` or from the web ui

* Create or append the following content to the file `/etc/libvirt/hooks/qemu`:

```bash
#!/bin/bash

# IMPORTANT: Change the "VM NAME" string to match your actual VM Name.
# In order to create rules to other VMs, just duplicate the below block and configure
# it accordingly.
if [ "${1}" = "VM NAME" ]; then

 # Update the following variables to fit your setup
 GUEST_IP=
 GUEST_PORT=
 HOST_PORT=

 if [ "${2}" = "stopped" ] || [ "${2}" = "reconnect" ]; then
  /sbin/iptables -D FORWARD -o virbr0 -p tcp -d $GUEST_IP --dport $GUEST_PORT -j ACCEPT
  /sbin/iptables -t nat -D PREROUTING -p tcp --dport $HOST_PORT -j DNAT --to $GUEST_IP:$GUEST_PORT
 fi
 if [ "${2}" = "start" ] || [ "${2}" = "reconnect" ]; then
  /sbin/iptables -I FORWARD -o virbr0 -p tcp -d $GUEST_IP --dport $GUEST_PORT -j ACCEPT
  /sbin/iptables -t nat -I PREROUTING -p tcp --dport $HOST_PORT -j DNAT --to $GUEST_IP:$GUEST_PORT
 fi
fi
```

* Make the hook executable:

```bash
sudo chmod +x /etc/libvirt/hooks/qemu
```

* Restart the `libvirtd` service:

```bash
sudo systemctl restart libvirtd.service
```

* Start the guest


> Note: this guide is based on https://wiki.libvirt.org/Networking.html