The /etc/resolv.conf problem comes back

[peer]

Hardware: ARM board
YunoHost version: 4.1.7.3
I have access to my server : Through SSH | through the webadmin

Hello!

I installed Yunohost, and the Diagnosis tool gave me this:

DNS resolution seems to be working, but it looks like you're using a custom /etc/resolv.conf.

    The file /etc/resolv.conf should be a symlink to /etc/resolvconf/run/resolv.conf itself pointing to 127.0.0.1 (dnsmasq). If you want to manually configure DNS resolvers, please edit /etc/resolv.dnsmasq.conf.

I found this issue was already reported and solved in the forum, so I applied @Aleks’ solution and it worked great.

The day after I found the problem was there again. I was not sure if I applied Aleks’ solution correctly, so I reapplied it and everything worked great again.

But not that great, because today I see the problem remains there!

Maybe the solution does not survive a reboot. Because these days I have been rebooting the system.

How could I have a permanent solution?

Thank you.

[Aleks]

Zblerg

can you tell what ARM board you’re running and if you used the pre-installed image or some external armbian image ?

[peer]

Wow, it seems like you already know my setup!

It’s a Lime2. Armbian installed manually. Then I manually installed Yunohost.

[Aleks]

Hmmmokay and what’s the content of /etc/resolv.conf when the issue shows up again ?

(Using for example: cat /etc/resolv.conf)

[peer]

peer@ynh:~$ cat /etc/resolv.conf
# Generated by NetworkManager
search lan mydomain.tld
nameserver (one IPv4 address here)
nameserver (one IPv4 address here)
nameserver (one IPv4 address here)
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver (one IPv4 address here)
nameserver (one IPv4 address here)
nameserver (one IPv6 address here)
nameserver (one IPv4 address here) 

[Aleks]

Ah I see … that’s goddamn NetworkManager messing with the file …

Naively I would uninstall it … not sure what’s the package name, maybe network-manager, so : apt remove network-manager

Or if that’s not the right name, let’s find it with dpkg --list | grep -i manager

[peer]

Done. Thank you very much Aleks!!

Do you know about any other thing I should pay attention to because of the manual installation?

[peer]

@Aleks Things got worse… I rebooted to check if the solution keeps permanent and… it happened: I don’t have network now.

The leds of the network interface are off.

I tried to use the HDMI connection: no success.

[Aleks]

Hmpf …

If you are comfortable with mounting sd cards and stuff, you could try mounting the sd card on your computer and adding this content in the /etc/network/interfaces.d/eth0.conf of the card (i believe the file doesnt exist already, it should be created) :

auth eth0
allow-hotplug eth0
iface eth0 inet dhcp

[peer]

Thank you.

I did another thing, I got in through serial.

This is what I have:

admin@ynh:/etc/network$ ls -hal
total 36K
drwxr-xr-x   7 root root 4.0K Mar  6 14:56 .
drwxr-xr-x 113 root root 4.0K Mar  9 01:17 ..
drwxr-xr-x   2 root root 4.0K Mar  6 18:56 if-down.d
drwxr-xr-x   2 root root 4.0K Mar  6 18:55 if-post-down.d
drwxr-xr-x   2 root root 4.0K Mar  5 15:30 if-pre-up.d
drwxr-xr-x   2 root root 4.0K Mar  6 18:56 if-up.d
-rw-r--r--   1 root root  106 Mar  6 14:56 interfaces
drwxr-xr-x   2 root root 4.0K Jan 28  2019 interfaces.d
-rw-r--r--   1 root root  106 Feb 14 22:04 interfaces.default
admin@ynh:/etc/network$ 
admin@ynh:/etc/network$ ls -hal interfaces.d
total 8.0K
drwxr-xr-x 2 root root 4.0K Jan 28  2019 .
drwxr-xr-x 7 root root 4.0K Mar  6 14:56 ..
admin@ynh:/etc/network$ 
admin@ynh:/etc/network$ cat interfaces
source /etc/network/interfaces.d/*
# Network is managed by Network manager
auto lo
iface lo inet loopback
admin@ynh:/etc/network$ 
admin@ynh:/etc/network$ cat interfaces.default 
source /etc/network/interfaces.d/*
# Network is managed by Network manager
auto lo
iface lo inet loopback
admin@ynh:/etc/network$ 

So, should I add that eth0.conf as suggested?

[peer]

I added the file as you suggested, but I guess I’m doing something wrong:

root@ynh:/etc/network/interfaces.d# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 02:01:0a:82:a6:e4 brd ff:ff:ff:ff:ff:ff
root@ymh:/etc/network/interfaces.d# 
root@ynh:/etc/network/interfaces.d# ifup eth0
ifup: /etc/network/interfaces.d/eth0.conf:1: misplaced option
ifup: unknown interface eth0
root@ynh:/etc/network/interfaces.d# 

[peer]

@Aleks

auth eth0

Solved!! There was just a typo there! I changed auth into auto.

And I have checked the DNS thing keeps solved too.

Anyway, if something comes up to your mind that I should check because of the manual installation I did, please let me know…

Thank you very much again!

[Aleks]

Hhmmm not really but I would naively ask why you ended up doing a manual install rather than using the preinstalled image (I have a few guesses)

[peer]

Yes, that’s the right question. The answer is I wanted to have the system encrypted and remotely unlockable.

[peer]

I mean having Dropbear in its unencrypted boot partition. So when the board boots I can remotely access it to enter the passphrase which unencrypts the root partition to completely boot the system.