test-runner.py: support opkg in get_packages()

Yocto can use rpm, deb or opkg as binary packaging tool.
If distribution is not guessed correctly from /etc/os-release, or
if it doesn't match debian, fedora or ubuntu, then try the different
packaging tools to populate package list. This will work if tools
are on the rootfs also on custom distributions like the ones from
yocto build.

Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>

automated/utils/test-runner.py

@@ -629,6 +629,9 @@ def get_packages(linux_distribution, target=None, target_port=None):
     linux_distribution is a string that may be 'debian',
         'ubuntu', 'centos', or 'fedora'.
 
+    If linux_distribution is not provided, then rpm, dpkg and opkg
+    tools will be tried to get the package list.
+
     For example (ubuntu):
     'packages': ['acl-2.2.52-2',
                  'adduser-3.113+nmu3',
@@ -643,6 +646,11 @@ def get_packages(linux_distribution, target=None, target_port=None):
                  "zlib-1.2.7-17.el7",
                  "zlib-devel-1.2.7-17.el7"
     ]
+    (yocto/opkg):
+    "packages": ["alsa-conf - 1.2.6.1-r0.3",
+                 "alsa-state - 0.2.0-r5.3",
+                 ...
+    ]
     """
 
     logger = logging.getLogger("RUNNER.get_packages")
@@ -660,10 +668,31 @@ def get_packages(linux_distribution, target=None, target_port=None):
         ).splitlines()
     else:
         logger.warning(
-            "Unknown linux distribution '{}'; package list not populated.".format(
+            "Unknown linux distribution '{}'; trying to populate package list.".format(
                 linux_distribution
             )
         )
+        try:
+            packages = run_command(
+                "which rpm > /dev/null && rpm -qa --qf '%{NAME}-%{VERSION}-%{RELEASE}\n'", target, target_port
+            ).splitlines()
+        except subprocess.CalledProcessError:
+            pass
+        logger.debug("packages = %s" % packages)
+        try:
+            packages += run_command(
+                "which dpkg > /dev/null && dpkg-query -W -f '${package}-${version}\n'", target, target_port
+            ).splitlines()
+        except subprocess.CalledProcessError:
+            pass
+        logger.debug("packages = %s" % packages)
+        try:
+            packages += run_command(
+                "which opkg > /dev/null && opkg list-installed", target, target_port
+            ).splitlines()
+        except subprocess.CalledProcessError:
+            pass
+        logger.debug("packages = %s" % packages)
 
     packages.sort()
     return packages