Use standard reference to usable Vagrant base box.

[fabacab]

This PR was started because when I tried to use this project, I noticed that when cloning this repo, the project seems to be a bit incomplete?

The first issue I ran into when trying it out is that the Vagrantfile points to a non-existent gateway VM's Vagrant base box. I inferred from the name that you intended to use the ubuntu/bionic64 base box available from the canonical Vagrant Cloud base box registry, but when I tried to use that base box, I got a dnsmasq configuration error citing no existing interface named eth1.

This is because newer versions of the Ubuntu base box use systemd's predictable interface names, so I replaced the references to eth0 and eth1 with enp0s3 and enp0s8, respectively, in your provision-gateway.sh script.

With these changes, the Vagrant gateway now provisions without an issue. Hope this helps!

~NB: This PR is marked as a Work In Progress (WIP) because I'm running into another issue (the Alpine container on node pve2 cannot access the Internet due to a failure to reach the gateway). As an aside, do you know why that might be? More specifically:~ The issue described below has been resolved and is a separate issue, fixed in PR #8. More detail can be found on the Proxmox VE Wiki's "Proxmox VE inside VirtualBox" page.

while the cluster seemed to come online without an issue, but once Vagrant tried running the container provisioning script, it hung in this infinite loop:

    pve2: fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz
    pve2: fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz
    pve2: ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.10/main: temporary error (try again later)
    pve2: WARNING: Ignoring APKINDEX.00740ba1.tar.gz: No such file or directory
    pve2: 2 errors; 19 distinct packages available
    pve2: ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.10/community: temporary error (try again later)
    pve2: WARNING: Ignoring APKINDEX.d8b2a6f4.tar.gz: No such file or directory
    pve2: + 
    pve2: sleep
    pve2:  5

To explore the issue further, I attached to the container manually and, sure enough, there's no Internet access:

root@pve2:~# lxc-attach -n 100 /bin/sh
~ # traceroute -q 1 -w 1 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 46 byte packets
 1  *
 2  *
 3  *
 4  alpine-100 (10.1.0.100)  53.588 ms !H
~ # 

I confirmed that the container can ping the service LAN:

~ # ping 10.1.0.202
PING 10.1.0.202 (10.1.0.202): 56 data bytes
64 bytes from 10.1.0.202: seq=0 ttl=64 time=0.047 ms
^C
--- 10.1.0.202 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.047/0.047/0.047 ms

but the issue appears to be that the container cannot access the Vagrant-managed gateway VM at its expected adddress:

~ # ping 10.1.0.254
PING 10.1.0.254 (10.1.0.254): 56 data bytes
^C
--- 10.1.0.254 ping statistics ---
2 packets transmitted, 0 packets received, 100% packet loss
~ 

However, the Proxmox VE nodes themselves can reach the gateway:

root@pve2:~# ping 10.1.0.254
PING 10.1.0.254 (10.1.0.254) 56(84) bytes of data.
64 bytes from 10.1.0.254: icmp_seq=1 ttl=64 time=0.400 ms
^C
--- 10.1.0.254 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.400/0.400/0.400/0.000 ms

[fabacab]

I have fixed the issue with the nested container not being able to access the Internet and submitted PR #8 to address the matter.