amdump reports nonexistent log files due to timezone error

[Eric Towers]

A run of amdump generated a report (captured in e-Mail) with the NOTES entry

planner: client0004 sda1 20180720004501 0 "/usr/lib/amanda/runtar exited with
status 1: see /var/log/amanda/client/Weirdhouse/sendsize.20180719194502.debug"

The file /var/log/amanda/client/Weirdhouse/sendsize.20180719194502.debug does not exist.
The file /var/log/amanda/client/Weirdhouse/sendsize.20180720004502.debug does exist.

Note that the timestamp of the note is 20180720004501. The timestamps in the two filenames differ by exactly 5 hours.

Cause: The server Amanda backup user is in the UTC timezone.

backup@server:~$ timedatectl
      Local time: Fri 2018-07-20 02:33:32 UTC
  Universal time: Fri 2018-07-20 02:33:32 UTC
        RTC time: Fri 2018-07-20 02:33:33
       Time zone: Etc/UTC (UTC, +0000)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

The client Amanda backup user is in the CDT timezone.

backup@client:~$ timedatectl
      Local time: Thu 2018-07-19 21:33:33 CDT
  Universal time: Fri 2018-07-20 02:33:33 UTC
        RTC time: Fri 2018-07-20 02:33:32
       Time zone: America/Chicago (CDT, -0500)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

There is a 5 hour difference between the two local times. (The two timedatectl invocations were hand generated, so the 1 second difference is user induced.)

Consequence: Amdump uses the local time at the client to determine the timestamp used in the log file name in the report, but uses the local time at the server to determine the name of the log file on disk. As a consequence, the amdump report references nonexistent files.

Follow-on consequence: In a sufficiently busy Amanda environment, with a little coincidental timing (not so rare, given how *crons work), the log file referenced in the report can actually be the log file for an unrelated backup event.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: amanda-server 1:3.3.6-4.1
ProcVersionSignature: Ubuntu 4.4.0-77.98-generic 4.4.59
Uname: Linux 4.4.0-77-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
Date: Fri Jul 20 02:25:44 2018
InstallationDate: Installed on 2014-12-18 (1310 days ago)
InstallationMedia: Ubuntu-Server 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.3)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: amanda
UpgradeStatus: Upgraded to xenial on 2016-08-09 (709 days ago)