`DNS is off!` rather than `System is healthy`.

[yubiuser]

    @yubiuser When using `development` branch of `PADD` (as of yesterday) I'm getting a new bug where I see `DNS is off!` rather than `System is healthy`. 

This changed a few hours after switching (things were fine initially, but changed over night).

There's no actual issue with DNS, the PiHole is working as expected and is blocking normally.

Edit 1: I just rebooted and see System is healthy again. Will report back if I see it change again.

Edit 2: DNS is off! is back 15 minutes after reboot.

Originally posted by @christianboyle in pi-hole/pi-hole#5059 (comment)

[yubiuser]

This is interesting. We fixed a bug in PADD that would always report FTL as running in #304

[yubiuser]

The only condition that can lead to DNS is off while FTL: Running is when FTL is running but "dns-port" returned from the API is 0(meaning DNS is switched off)

PADD/padd.sh

Lines 425 to 426 in 1cf30ee

	# ${ftl_dns_port} == 0 DNS server part of dnsmasq disabled, ${ftl_status} == "Not running" no ftlPID found
	if [ "${ftl_dns_port}" = 0 ] || [ "${ftl_status}" = "Not running" ]; then

[christianboyle]

Very strange. This is the first time I've seen this message and haven't made any changes to my network recently. I guess we'll just have to see if any others run into this with the new version.

[christianboyle]

Inexplicably, this issue resolved itself after being broken for 2 days. Not sure if it was something intermittent, but will keep an eye out in case it happens again.

I assume we can close this issue for now.

[rdwebdesign]

If you need, we can reopen the issue.

[christianboyle]

Looks like things changed back over night. Not sure what's going on as I still haven't had any changes to my network or PiHole.

[yubiuser]

Ok, I see a possible pitfall we created:

PADD/padd.sh

Line 423 in 1cf30ee

ftl_dns_port=$(GetFTLData "dns-port")

askes for returning the current DNS port. The function will return 0 if DNS is disabled in pihole-FTL. However, we also return 0 in GetFTLData() if we fail to get the telnet API port

PADD/padd.sh

Lines 114 to 124 in 1cf30ee

	GetFTLData() {
	local ftl_port data
	ftl_port=$(getFTLAPIPort)
	if [ -n "$ftl_port" ]; then
	# Send command to FTL and ask to quit when finished
	data="$(echo ">$1 >quit" | nc 127.0.0.1 "${ftl_port}")"
	echo "${data}"
	else
	echo "0"
	fi
	}

I don't know why we are failing to get the telnet port yet, but I'll prepare a fix to not use 0 both as signal for failure and as actual data.

[yubiuser]

What is the content of your /etc/pihole/pihole-FTL.conf?

[christianboyle]

#; Pi-hole FTL config file
#; Comments should start with #; to avoid issues with PHP and bash reading this file
RATE_LIMIT=1000/60
PRIVACYLEVEL=0

[yubiuser]

Ok, this looks not suspicious. Could you check your /var/log/pihole/FTL.log for any errors or (unintended restarts ) please?

[christianboyle]

[2022-12-22 02:28:16.565 887M] Resizing "FTL-dns-cache" from 143360 to (9216 * 16) == 147456 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 08:15:33.662 887M] Resizing "FTL-dns-cache" from 147456 to (9472 * 16) == 151552 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 10:18:28.352 887M] Resizing "FTL-dns-cache" from 151552 to (9728 * 16) == 155648 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 11:14:42.058 887M] Resizing "FTL-dns-cache" from 155648 to (9984 * 16) == 159744 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 11:35:47.581 887M] Resizing "FTL-domains" from 143360 to (8192 * 20) == 163840 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 11:53:17.596 887M] WARNING in dnsmasq core: reducing DNS packet size for nameserver 2001:4860:4860::8888 to 1232
[2022-12-22 11:54:17.715 887M] Resizing "FTL-dns-cache" from 159744 to (10240 * 16) == 163840 (/dev/shm: 7.0MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 15:30:44.377 887M] Resizing "FTL-strings" from 245760 to (286720 * 1) == 286720 (/dev/shm: 7.0MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-22 15:44:04.615 887M] Resizing "FTL-dns-cache" from 163840 to (10496 * 16) == 167936 (/dev/shm: 7.0MB used, 483.5MB total, FTL uses 7.0MB)

[rdwebdesign]

Look at /var/log/pihole/FTL.log.1 to search for errors from yesterday.

[christianboyle]

FTL.log.1

[2022-12-21 01:16:55.599 887M] Resizing "FTL-dns-cache" from 110592 to (7168 * 16) == 114688 (/dev/shm: 6.8MB used, 483.5MB total, FTL uses 6.8MB)
[2022-12-21 07:48:57.925 887M] Resizing "FTL-dns-cache" from 114688 to (7424 * 16) == 118784 (/dev/shm: 6.8MB used, 483.5MB total, FTL uses 6.8MB)
[2022-12-21 09:11:47.495 887M] Resizing "FTL-strings" from 204800 to (245760 * 1) == 245760 (/dev/shm: 6.8MB used, 483.5MB total, FTL uses 6.8MB)
[2022-12-21 09:28:35.993 887M] WARNING in dnsmasq core: reducing DNS packet size for nameserver 8.8.8.8 to 1232
[2022-12-21 10:54:35.014 887M] Resizing "FTL-dns-cache" from 118784 to (7680 * 16) == 122880 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 11:12:15.912 887M] Resizing "FTL-dns-cache" from 122880 to (7936 * 16) == 126976 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 11:28:48.320 887M] Resizing "FTL-domains" from 122880 to (7168 * 20) == 143360 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 13:09:15.353 887M] Resizing "FTL-dns-cache" from 126976 to (8192 * 16) == 131072 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 15:55:24.569 887M] Resizing "FTL-dns-cache" from 131072 to (8448 * 16) == 135168 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 19:44:01.224 887M] Resizing "FTL-dns-cache" from 135168 to (8704 * 16) == 139264 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)
[2022-12-21 20:40:40.957 887M] Resizing "FTL-dns-cache" from 139264 to (8960 * 16) == 143360 (/dev/shm: 6.9MB used, 483.5MB total, FTL uses 6.9MB)

I use Google for upstream DNS in case that matters: