chrony autopkgtest "time-sources-from-dhcp-servers" fails (produces stderr)

[Rafael David Tinoco]

iproute2 fix in -proposed (https://launchpad.net/ubuntu/+source/iproute2/4.18.0-1ubuntu3) has showed regressions in chrony autopkgtest (object of this bug report).

From autopkgtest output:

"""
Generating /etc/default/isc-dhcp-server...
Created symlink /etc/systemd/system/multi-user.target.wants/isc-dhcp-server.service → /lib/systemd/system/isc-dhcp-server.service.
Created symlink /etc/systemd/system/multi-user.target.wants/isc-dhcp-server6.service → /lib/systemd/system/isc-dhcp-server6.service.
Setting up autopkgtest-satdep (0) ...
Processing triggers for systemd (240-6ubuntu9) ...
Processing triggers for man-db (2.8.5-2) ...
Processing triggers for libc-bin (2.29-0ubuntu2) ...
(Reading database ... 62774 files and directories currently installed.)
Removing autopkgtest-satdep (0) ...
autopkgtest [20:50:33]: test time-sources-from-dhcp-servers: [-----------------------
Preparing the dummy network interface and dhcpd configuration…
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v4-dummy0.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v6-dummy0.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v4-dummy0.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v6-dummy0.conf: No such file or directory
Done!

Check if the NTP server is made available to chronyd…
SUCCESS!

Release the current lease and check if the NTP server has been correctly removed…
SUCCESS!
"""

It is likely that the stdout from md5sum coming out of the dhclient command caused the "regression".

I have reproduced the issue by hand doing:

$ apt-get install isc-dhcp-server
$ modprobe dummy

$ ip link add name dummy0 type dummy
$ ip address add 192.168.1.1/24 dev dummy0
$ ip link set dev dummy0 up

cat <<EOF > /etc/dhcp/dhcpd.conf
default-lease-time 600;
max-lease-time 7200;
authorative;

subnet 192.168.1.0 netmask 255.255.255.0 {
    option subnet-mask 255.255.255.0;
    option broadcast-address 192.168.1.255;
    option ntp-servers 192.168.1.50;
    range 192.168.1.42 192.168.1.100;
}
EOF

$ sed -i 's/INTERFACESv4=""/INTERFACESv4="dummy0"/' /etc/default/isc-dhcp-server

and

$ systemctl restart isc-dhcp-server

$ dhclient dummy0 <- problem happens here

It could be a "isc-dhcp-client"problem, but I'll keep this bug linked to another bug if that is the case.

[Rafael David Tinoco (rafaeldtinoco)]

When trying a simple dhclient running on a bridge called "teste":

(c)inaddy@eoanchrony:~/work/sources/ubuntu/chrony/debian/tests$ sudo dhclient teste
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v4-teste.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v6-teste.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v4-teste.conf: No such file or directory
md5sum: /run/systemd/resolved.conf.d/isc-dhcp-v6-teste.conf: No such file or directory

The problem is caused by the hook script:

/etc/dhcp/dhclient-enter-hooks.d/resolved

In the following line:

md5sum $statedir/isc-dhcp-v4-$interface.conf $statedir/isc-dhcp-v6-$interface.conf &> $oldstate

[Rafael David Tinoco (rafaeldtinoco)]

@xnox,

remember that issue on systemd with:

b/debian/extra/dhclient-enter-resolved-hook

I think the following systemd patch:

+systemd (240-6ubuntu9) eoan; urgency=medium
+
+ * Fix typpo in storage test.
+ File: debian/tests/storage
+ https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=f28aa5fe4ab175b99b6ea702559c59ca473b4ca
8
+
+ * Fix bashism
+ File: debian/extra/dhclient-enter-resolved-hook
+ https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=0725c1169ddde4f41cacba7af3e546704e2206b
e
+
+ -- Dimitri John Ledkov <email address hidden> Thu, 30 May 2019 21:45:50 +0100

Caused the issue above ^ (with the md5sum line). I'm opening a systemd bug for that.

[Rafael David Tinoco (rafaeldtinoco)]

Related case:

systemd dhclient hook is causing md5sum cmds in inexistent files
https://bugs.launchpad.net/ubuntu/+bug/1832053

[Dimitri John Ledkov (xnox)]

argh! yes, must fix.

[Rafael David Tinoco (rafaeldtinoco)]

There also another chrony regression being investigated here:

https://bugs.launchpad.net/ubuntu/+source/chrony/+bug/1836929

[Rafael David Tinoco (rafaeldtinoco)]

Dimitri,

We fixed chrony's autopkgtest issue by allowing stderr during the test. This case is still "on" as the dhclient hooks were the ones causing stderr to chrony's tests (fyio). I have marked LP: #1832053 as a duplicate of this and marked affecting systemd only.

Thanks!