DNS service not running on Raspberry Pi 4B

yubiuser · January 5, 2022, 5:49am

We are working on a fix already, see this comment:

Dashboard header reports an incorrect status when running on docker

opened 04:44PM - 21 Dec 20 UTC

closed 09:02AM - 07 Jan 22 UTC

### Versions Running docker tag image `v5.2.1`, `$ docker exec -it pihole pihol…e -v`: - Pi-hole version is v5.2.1 (Latest: v5.2.1) - AdminLTE version is v5.2.1 (Latest: v5.2.1) - FTL version is v5.3.2 (Latest: v5.3.2) ### Platform Running using docker tag image `v5.2.1`, - OS and version: Debian `10.5` - Platform: Docker on Raspberry Pi ### Expected behavior Status in the dashboard should show: "Active" ### Actual behavior / bug Status in the dashboard shows: "DNS service not running" ### Steps to reproduce Steps to reproduce the behavior: 1. Run the default image without adding any additional cap - no DHCP required 1. Point the browser to the web interface Asking for the `pihole status` shows: ```bash $ docker exec -it pihole pihole status [✗] DNS service is NOT listening ``` while if you add the following argument to the `docker run` command, `--cap-add=SYS_PTRACE`, you'll get: ```bash $ docker exec -it pihole pihole status [✓] DNS service is listening [✓] UDP (IPv4) [✓] TCP (IPv4) [✓] UDP (IPv6) [✓] TCP (IPv6) [✓] Pi-hole blocking is enabled ``` This is a regression added w/ https://github.com/pi-hole/pi-hole/commit/6009e869471f7f1da0593d91d82855340c8643b1 since `lsof` requires to read `/proc/*/stat`. See [ptrace(2)](https://man7.org/linux/man-pages/man2/ptrace.2.html). When the cap is there: ```bash $ docker exec -it pihole lsof -Pni:53 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME pihole-FT 835 pihole 4u IPv4 121563 0t0 UDP *:53 pihole-FT 835 pihole 5u IPv4 121564 0t0 TCP *:53 (LISTEN) pihole-FT 835 pihole 6u IPv6 121565 0t0 UDP *:53 pihole-FT 835 pihole 7u IPv6 121566 0t0 TCP *:53 (LISTEN) ``` Shortly: `lsof` is not Docker friendly unless using `CAP_SYS_PTRACE`. I'm not sure if the fix here is just to make a clear mention of the new cap requirement in the README or to find another way to provide that beautiful report. HTH, Matteo