VM keeps changing its IP address

[Peeja]

I'm going in circles with this one.

I bring up the fresh VM. I $(dvm env). I also check to see what that exports:

❯❯❯ dvm env
export DOCKER_HOST=tcp://192.168.42.43:4243

If I dvm ssh and check ifconfig, sure enough, that's the IP address.

eth1      Link encap:Ethernet  HWaddr 08:00:27:6B:6F:FF
          inet addr:192.168.42.43  Bcast:192.168.42.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe6b:6fff/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1388 (1.3 KiB)  TX bytes:1838 (1.7 KiB)

And docker commands work fine. Great.

Then, a little while later, docker commands stop working. I can't ping 192.168.42.43 anymore. So I dvm ssh back in:

eth1      Link encap:Ethernet  HWaddr 08:00:27:6B:6F:FF
          inet addr:192.168.56.102  Bcast:192.168.56.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe6b:6fff/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2672 errors:0 dropped:0 overruns:0 frame:0
          TX packets:350 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3838330 (3.6 MiB)  TX bytes:26060 (25.4 KiB)

It's moved to 192.168.56.102.

dvm reload correctly resets the VM's IP address (along with the entire machine).

Any clue what could be going on here? I haven't found a pattern to my activity that could be causing it.

[jopecko]

@Peeja I was experiencing the same issue recently. I haven't had a chance to determine the root cause, however, I have a workaround that allows me to continue working without this issue recurring. If I export the DOCKER_IP env var with an address in the 24-bit block, i.e., 10.0.0.0 - 10.255.255.255, before invoking dvm up, the IP address on my VM remains stable and available.

[dotkrnl]

Same issue experienced.

[corporate-gadfly]

similar to #4. Do any of you connect to different networks?

[Peeja]

@opeckojo Huh. I've already got a 10.* address on my VM's eth0. Do you? I'm not clear what the difference between those interfaces is.

@corporate-gadfly I just connect to a single Wi-Fi network.

[jopecko]

@Peeja I think it may be interface eth1 which is the one configured by Vagrant for the private network IP. If I bring up the Virtualbox GUI, the MAC address listed for the vboxnet1 adapter matches the MAC Address for eth1. I can't say for certain why an address in the 16-bit block, 192.168.0.0 - 192.168.255.255, causes this issue, however, for me, changing to a 24-bit block address completely resolved this issue. Before changing my VM's IP, I would be able to communicate with the VM via docker for maybe an hour and then I would no longer be able to connect. Doing a full restart or reload were the only ways I could reestablish connectivity. Since I switched to a 24-bit block IP address, I've had my VM up for over 24 hours and am still able to communicate with it via docker running locally on my Mac.

All I did was set the DOCKER_IP environment variable to a 24-bit block address, in my case 10.211.55.255, eval my dvm env to sync up my session, bring up my VM and work as described in the docs herein.

I admit I don't know the specifics of what's actually occurring under the covers and why the 192.168.42.43 address is causing this problem with Virtualbox and Vagrant's private network. If I get time to dive in and uncover anything I'll be sure and update this issue.

[fnichol]

Finally, I think we've tracked this down to a udhcpc process which Tiny Core Linux auto-starts on boot. (More details in #35). Thank you all for your help in diagnosing!