avocado_qemu: Fix KNOWN_DISTROS map into the LinuxDistro class

As the KNOWN_DISTROS grows, more loosely methods will be created in
the avocado_qemu/__init__.py file.

Let's refactor the code so that KNOWN_DISTROS and related methods are
packaged in a class

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20210706131729.30749-2-eric.auger@redhat.com>
[CR: moved aarch64 definition from patch 2 to 1]
[CR: protect get() when arch is not defined]
[CR: split long lines]
Acked-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>

tests/acceptance/avocado_qemu/__init__.py

@@ -306,34 +306,50 @@ def ssh_command(self, command):
                          f'Guest command failed: {command}')
         return stdout_lines, stderr_lines
 
+class LinuxDistro:
+    """Represents a Linux distribution
 
-#: A collection of known distros and their respective image checksum
-KNOWN_DISTROS = {
-    'fedora': {
-        '31': {
-            'x86_64':
-            {'checksum': ('e3c1b309d9203604922d6e255c2c5d09'
-                          '8a309c2d46215d8fc026954f3c5c27a0')},
-            'aarch64':
-            {'checksum': ('1e18d9c0cf734940c4b5d5ec592facae'
-                          'd2af0ad0329383d5639c997fdf16fe49')},
-            'ppc64':
-            {'checksum': ('7c3528b85a3df4b2306e892199a9e1e4'
-                          '3f991c506f2cc390dc4efa2026ad2f58')},
-            's390x':
-            {'checksum': ('4caaab5a434fd4d1079149a072fdc789'
-                          '1e354f834d355069ca982fdcaf5a122d')},
+    Holds information of known distros.
+    """
+    #: A collection of known distros and their respective image checksum
+    KNOWN_DISTROS = {
+        'fedora': {
+            '31': {
+                'x86_64':
+                {'checksum': ('e3c1b309d9203604922d6e255c2c5d09'
+                              '8a309c2d46215d8fc026954f3c5c27a0')},
+                'aarch64':
+                {'checksum': ('1e18d9c0cf734940c4b5d5ec592facae'
+                              'd2af0ad0329383d5639c997fdf16fe49')},
+                'ppc64':
+                {'checksum': ('7c3528b85a3df4b2306e892199a9e1e4'
+                              '3f991c506f2cc390dc4efa2026ad2f58')},
+                's390x':
+                {'checksum': ('4caaab5a434fd4d1079149a072fdc789'
+                              '1e354f834d355069ca982fdcaf5a122d')},
             }
         }
     }
 
+    def __init__(self, name, version, arch):
+        self.name = name
+        self.version = version
+        self.arch = arch
+        try:
+            info = self.KNOWN_DISTROS.get(name).get(version).get(arch)
+        except AttributeError:
+            # Unknown distro
+            info = None
+        self._info = info or {}
 
-def get_known_distro_checksum(distro, distro_version, arch):
-    try:
-        return KNOWN_DISTROS.get(distro).get(distro_version).\
-            get(arch).get('checksum')
-    except AttributeError:
-        return None
+    @property
+    def checksum(self):
+        """Gets the cloud-image file checksum"""
+        return self._info.get('checksum', None)
+
+    @checksum.setter
+    def checksum(self, value):
+        self._info['checksum'] = value
 
 
 class LinuxTest(Test, LinuxSSHMixIn):
@@ -344,24 +360,24 @@ class LinuxTest(Test, LinuxSSHMixIn):
     """
 
     timeout = 900
-    distro_checksum = None
+    distro = None
     username = 'root'
     password = 'password'
 
     def _set_distro(self):
-        distro = self.params.get(
+        distro_name = self.params.get(
             'distro',
             default=self._get_unique_tag_val('distro'))
-        if not distro:
-            distro = 'fedora'
-        self.distro = distro
+        if not distro_name:
+            distro_name = 'fedora'
 
         distro_version = self.params.get(
             'distro_version',
             default=self._get_unique_tag_val('distro_version'))
         if not distro_version:
             distro_version = '31'
-        self.distro_version = distro_version
+
+        self.distro = LinuxDistro(distro_name, distro_version, self.arch)
 
         # The distro checksum behaves differently than distro name and
         # version. First, it does not respect a tag with the same
@@ -370,13 +386,9 @@ def _set_distro(self):
         # order of precedence is: parameter, attribute and then value
         # from KNOWN_DISTROS.
         distro_checksum = self.params.get('distro_checksum',
-                                          default=self.distro_checksum)
-        if not distro_checksum:
-            distro_checksum = get_known_distro_checksum(self.distro,
-                                                        self.distro_version,
-                                                        self.arch)
+                                          default=None)
         if distro_checksum:
-            self.distro_checksum = distro_checksum
+            self.distro.checksum = distro_checksum
 
     def setUp(self, ssh_pubkey=None, network_device_type='virtio-net'):
         super(LinuxTest, self).setUp()
@@ -418,14 +430,14 @@ def download_boot(self):
         self.log.info('Downloading/preparing boot image')
         # Fedora 31 only provides ppc64le images
         image_arch = self.arch
-        if self.distro == 'fedora':
+        if self.distro.name == 'fedora':
             if image_arch == 'ppc64':
                 image_arch = 'ppc64le'
 
         try:
             boot = vmimage.get(
-                self.distro, arch=image_arch, version=self.distro_version,
-                checksum=self.distro_checksum,
+                self.distro.name, arch=image_arch, version=self.distro.version,
+                checksum=self.distro.checksum,
                 algorithm='sha256',
                 cache_dir=self.cache_dirs[0],
                 snapshot_dir=self.workdir)