Bug#842301: autopkgtest: please capture the testbed's systemd Journal if present

[Simon McVittie]

Package: autopkgtest
Version: 4.1
Severity: wishlist
Tags: patch

When testing system-level things, the test's stdout/stderr don't always
tell the full story: after a failure, it's often useful to read the
logs of the service under test (and related services). Since many recent
Debian-based systems use systemd, we have an easy way to gather
all the logs at once.

When running the test "foo", the attached patch adds "foo-journal"
in the results directory alongside "foo-stdout", if "journalctl --boot=-0"
produces output. If the test involves reboots, it also adds
"foo-journal-reboot1", "foo-journal-reboot2" and so on.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.7.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages autopkgtest depends on:
ii  apt-utils       1.3.1
ii  libdpkg-perl    1.18.10
ii  procps          2:3.3.12-2
ii  python3         3.5.1-4
ii  python3-debian  0.1.29

Versions of packages autopkgtest recommends:
ii  autodep8  0.8

Versions of packages autopkgtest suggests:
pn  lxc          <none>
pn  lxd-client   <none>
ii  qemu-system  1:2.7+dfsg-1
ii  qemu-utils   1:2.7+dfsg-1
ii  schroot      1.6.10-2+b1

-- no debconf information