dhcp not working on startup

[needlestack]

The udhcp server does not keep running after startup:

pi@rachel:~ $ service udhcpd status
  ● udhcpd.service - LSB: Start busybox udhcpd at boot time
    Loaded: loaded (/etc/init.d/udhcpd)
    Active: active (exited) since Wed 2016-03-09 19:30:03 UTC; 21h ago
    Process: 365 ExecStart=/etc/init.d/udhcpd start (code=exited, status=0/SUCCESS)

It should be "active (running)". The result is that clients connecting to the wifi hang forever waiting for an IP address. You can fix it with the following:

pi@rachel:~ $ sudo service udhcpd stop
pi@rachel:~ $ sudo service udhcpd start

Which will get it running again, but the same problem will appear on reboot.

[mattneel]

Could you post the output of (as root):

cat /var/log/syslog | grep udhcpd

Should shed some light on why udhcpd isn't starting correctly.

[needlestack]

Thanks for the pointer! The output - this includes the messages during inital boot, rachel install, and a manual stop/start by me:

Mar  9 18:45:54 raspberrypi systemd[1]: Starting LSB: Start busybox udhcpd at boot time...
Mar  9 18:45:54 raspberrypi udhcpd[7646]: udhcpd: Disabled. Edit /etc/default/udhcpd to enable it.
Mar  9 18:45:54 raspberrypi systemd[1]: Started LSB: Start busybox udhcpd at boot time.
Mar  9 18:46:10 raspberrypi systemd[1]: Started LSB: Start busybox udhcpd at boot time.
Mar 10 17:06:48 raspberrypi systemd[1]: Stopping LSB: Start busybox udhcpd at boot time...
Mar 10 17:06:48 raspberrypi udhcpd[26218]: Stopping very small Busybox based DHCP server: No /usr/sbin/udhcpd found running; none killed.
Mar 10 17:06:48 raspberrypi udhcpd[26218]: udhcpd.
Mar 10 17:06:48 raspberrypi systemd[1]: Stopped LSB: Start busybox udhcpd at boot time.
Mar 10 17:06:50 raspberrypi systemd[1]: Starting LSB: Start busybox udhcpd at boot time...
Mar 10 17:06:50 raspberrypi udhcpd[26255]: Starting very small Busybox based DHCP server: udhcpd.
Mar 10 17:06:50 raspberrypi systemd[1]: Started LSB: Start busybox udhcpd at boot time.
Mar 10 17:06:50 raspberrypi udhcpd[26259]: udhcpd (v1.22.1) started
Mar 10 17:06:50 raspberrypi udhcpd[26259]: max_leases=235 is too big, setting to 189
Mar 10 17:06:50 raspberrypi udhcpd[26259]: can't open '/var/lib/misc/udhcpd.leases': No such file or directory

There's already a few things I see there I can look into, which I will do now. Further advice is also appreciated.

[needlestack]

Maybe this is more helpful - just the messages post boot:

Mar 10 17:12:53 raspberrypi systemd[1]: Stopping LSB: Start busybox udhcpd at boot time...
Mar 10 17:12:53 raspberrypi udhcpd[26259]: Received SIGTERM
Mar 10 17:12:53 raspberrypi udhcpd[26407]: Stopping very small Busybox based DHCP server: Stopped /usr/sbin/udhcpd (pid 26259).
Mar 10 17:12:53 raspberrypi udhcpd[26407]: udhcpd.
Mar 10 17:13:02 rachel systemd[1]: Starting LSB: Start busybox udhcpd at boot time...
Mar 10 17:13:02 rachel udhcpd[363]: Starting very small Busybox based DHCP server: udhcpd.
Mar 10 17:13:02 rachel udhcpd[387]: udhcpd (v1.22.1) started
Mar 10 17:13:02 rachel udhcpd[387]: max_leases=235 is too big, setting to 189
Mar 10 17:13:02 rachel udhcpd[387]: is interface wlan0 up and configured?: Cannot assign requested address
Mar 10 17:13:02 rachel systemd[1]: Started LSB: Start busybox udhcpd at boot time.

[mattneel]

Okay, if this is post boot, then something is explicitly stopping the udhcpd service, as evidenced by the first message.

[mattneel]

If I had to guess, I'd say this is happening because wlan0 isn't up and configured by the time udhcpd is trying to start.

[needlestack]

Possibly related: when I run ifconfig, it does show wlan0, but with a different IP address than expected - it's supposed to be 10.10.10.10 but comes up as 169.254.131.32 which looks self-assigned to me.

I'm still green with the details of linux network configuration - thanks for your help.

[mattneel]

I'll review the network configuration and play with things. Worst case scenario is to maybe add a post-up line to /etc/network/interfaces to restart udhcpd everytime wlan0 comes up.

[mattneel]

Can confirm udhcpd is having an issue because wlan0 is not configured correctly at the time of boot.
If you manually set the wlan0 address (ifconfig wlan0 10.10.10.10) and restart udhcpd (service udhcpd restart) everything functions as expected (also got it working on a TP-Link TL-WN725N adapter, will play with dynamically gathering wifi driver during installation soon).

Investigating why our /etc/network/interfaces configuration is not being honored now.

[needlestack]

Any new insights? I'm about to dig into this and wanted to check if you made any headway first...

[mattneel]

Haven't had the time lately to play with things on-device. It may be something internal to Raspbian's network handling (this reminds me of NetworkManager taking over settings in Ubuntu).

[j-schwartz]

I think we need to edit /etc/network/interfaces to replace (if it exists) "iface wlan0 inet dhcp" to (or add):

iface wlan0 inet static
address 10.10.10.10
netmask 255.255.255.0

This should assign the static IP 10.10.10.10 at boot.

We will also need to comment out the following lines if they exist:

allow-hotplug wlan0
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet manual

I don't have a clean version to test this on right now, just trying to read through the github. My script is running though so I should be able to confirm in the next 30 minutes or so.

[j-schwartz]

Nevermind... this appears to be correctly set currently.

[j-schwartz]

I screwed up this most recent image testing, but I'm wondering how terrible it would be to just throw:

ifconfig wlan0 10.10.10.10
service udhcpd restart

in etc/rc.local

[j-schwartz]

the above seems to work for now. Obviously, I want to figure out what is going on, but given a deadline here, I think we throw

ifconfig wlan0 10.10.10.10
service udhcpd restart

in /etc/rc.local

I will have Norberto look on Friday

[needlestack]

Plenty good enough for now - I've added this to installer.py and it seems to work great!