tests: integration test cleanup and full pass of nocloud-kvm.

Integration test harness changes:
 * Enable collection of console log in nocloud-kvm and lxd.
 * Collect the console log to results for all test runs.
 * change 'tmpfile' to pick name locally instead of using 'mktemp'.
 * drop the 'instance' attribute from nocloud-kvm Image and
   demote LXDImage.instance to a private attribute.
   This is because Images do not actually have instances.
   (LXDImage internally uses a booted system to modify the image).
 * Add 'TargetBase' as a superclass of Image and Instance providing
   implementations of execute, read_data, write_data, pull_file,
   and push_file. These all depend on an implementation of _execute.
 * Improve '_execute' implementations to support accepting stdin.
 * execute supports 'rcs=False' meaning 'do not raise exception'.
 * Drop support for pylxd < 2.2. older versions cannot determine
   exit code of 'execute', which makes them unusable.
 * make NoCloudKVMInstance._execute run as root via sudo. This required
   some changes so that 'hostname' could be reverse-looked up in order
   to avoid sudo taking a long time (~20 seconds).
 * re-use existing ssh connection in nocloud-kvm.

Test changes here:
 * do not use /tmp, but rather /var/tmp (LP: #1707222)
 * make keys_to_console assertions more strict.
 * change user test cases to always add default (ubuntu) user
   so that nocloud-kvm's execute which operates over ssh can work.

3 files changed, 39 insertions, 54 deletions

diff --git a/tests/cloud_tests/images/base.py b/tests/cloud_tests/images/base.py
index 0a1e0563..d503108a 100644
--- a/tests/cloud_tests/images/base.py
+++ b/tests/cloud_tests/images/base.py
@@ -2,8 +2,10 @@
 
 """Base class for images."""
 
+from ..util import TargetBase
 
-class Image(object):
+
+class Image(TargetBase):
     """Base class for images."""
 
     platform_name = None
@@ -43,21 +45,6 @@ class Image(object):
         # NOTE: more sophisticated options may be requied at some point
         return self.config.get('setup_overrides', {})
 
-    def execute(self, *args, **kwargs):
-        """Execute command in image, modifying image."""
-        raise NotImplementedError
-
-    def push_file(self, local_path, remote_path):
-        """Copy file at 'local_path' to instance at 'remote_path'."""
-        raise NotImplementedError
-
-    def run_script(self, *args, **kwargs):
-        """Run script in image, modifying image.
-
-        @return_value: script output
-        """
-        raise NotImplementedError
-
     def snapshot(self):
         """Create snapshot of image, block until done."""
         raise NotImplementedError
diff --git a/tests/cloud_tests/images/lxd.py b/tests/cloud_tests/images/lxd.py
index fd4e93c2..5caeba41 100644
--- a/tests/cloud_tests/images/lxd.py
+++ b/tests/cloud_tests/images/lxd.py
@@ -24,7 +24,7 @@ class LXDImage(base.Image):
         @param config: image configuration
         """
         self.modified = False
-        self._instance = None
+        self._img_instance = None
         self._pylxd_image = None
         self.pylxd_image = pylxd_image
         super(LXDImage, self).__init__(platform, config)
@@ -38,9 +38,9 @@ class LXDImage(base.Image):
 
     @pylxd_image.setter
     def pylxd_image(self, pylxd_image):
-        if self._instance:
+        if self._img_instance:
             self._instance.destroy()
-            self._instance = None
+            self._img_instance = None
         if (self._pylxd_image and
                 (self._pylxd_image is not pylxd_image) and
                 (not self.config.get('cache_base_image') or self.modified)):
@@ -49,15 +49,19 @@ class LXDImage(base.Image):
         self._pylxd_image = pylxd_image
 
     @property
-    def instance(self):
-        """Property function."""
-        if not self._instance:
-            self._instance = self.platform.launch_container(
+    def _instance(self):
+        """Internal use only, returns a instance
+
+        This starts an lxc instance from the image, so it is "dirty".
+        Better would be some way to modify this "at rest".
+        lxc-pstart would be an option."""
+        if not self._img_instance:
+            self._img_instance = self.platform.launch_container(
                 self.properties, self.config, self.features,
                 use_desc='image-modification', image_desc=str(self),
                 image=self.pylxd_image.fingerprint)
-        self._instance.start()
-        return self._instance
+            self._img_instance.start()
+        return self._img_instance
 
     @property
     def properties(self):
@@ -144,20 +148,20 @@ class LXDImage(base.Image):
             shutil.rmtree(export_dir)
             shutil.rmtree(extract_dir)
 
-    def execute(self, *args, **kwargs):
+    def _execute(self, *args, **kwargs):
         """Execute command in image, modifying image."""
-        return self.instance.execute(*args, **kwargs)
+        return self._instance._execute(*args, **kwargs)
 
     def push_file(self, local_path, remote_path):
         """Copy file at 'local_path' to instance at 'remote_path'."""
-        return self.instance.push_file(local_path, remote_path)
+        return self._instance.push_file(local_path, remote_path)
 
     def run_script(self, *args, **kwargs):
         """Run script in image, modifying image.
 
         @return_value: script output
         """
-        return self.instance.run_script(*args, **kwargs)
+        return self._instance.run_script(*args, **kwargs)
 
     def snapshot(self):
         """Create snapshot of image, block until done."""
@@ -169,7 +173,7 @@ class LXDImage(base.Image):
         # clone current instance
         instance = self.platform.launch_container(
             self.properties, self.config, self.features,
-            container=self.instance.name, image_desc=str(self),
+            container=self._instance.name, image_desc=str(self),
             use_desc='snapshot', container_config=conf)
         # wait for cloud-init before boot_clean_script is run to ensure
         # /var/lib/cloud is removed cleanly
diff --git a/tests/cloud_tests/images/nocloudkvm.py b/tests/cloud_tests/images/nocloudkvm.py
index a7af0e59..1e7962cb 100644
--- a/tests/cloud_tests/images/nocloudkvm.py
+++ b/tests/cloud_tests/images/nocloudkvm.py
@@ -2,6 +2,8 @@
 
 """NoCloud KVM Image Base Class."""
 
+from cloudinit import util as c_util
+
 from tests.cloud_tests.images import base
 from tests.cloud_tests.snapshots import nocloudkvm as nocloud_kvm_snapshot
 
@@ -19,24 +21,11 @@ class NoCloudKVMImage(base.Image):
         @param img_path: path to the image
         """
         self.modified = False
-        self._instance = None
         self._img_path = img_path
 
         super(NoCloudKVMImage, self).__init__(platform, config)
 
     @property
-    def instance(self):
-        """Returns an instance of an image."""
-        if not self._instance:
-            if not self._img_path:
-                raise RuntimeError()
-
-            self._instance = self.platform.create_image(
-                self.properties, self.config, self.features, self._img_path,
-                image_desc=str(self), use_desc='image-modification')
-        return self._instance
-
-    @property
     def properties(self):
         """Dictionary containing: 'arch', 'os', 'version', 'release'."""
         return {
@@ -46,20 +35,26 @@ class NoCloudKVMImage(base.Image):
             'version': self.config['version'],
         }
 
-    def execute(self, *args, **kwargs):
+    def _execute(self, command, stdin=None, env=None):
         """Execute command in image, modifying image."""
-        return self.instance.execute(*args, **kwargs)
+        return self.mount_image_callback(command, stdin=stdin, env=env)
 
-    def push_file(self, local_path, remote_path):
-        """Copy file at 'local_path' to instance at 'remote_path'."""
-        return self.instance.push_file(local_path, remote_path)
+    def mount_image_callback(self, command, stdin=None, env=None):
+        """Run mount-image-callback."""
 
-    def run_script(self, *args, **kwargs):
-        """Run script in image, modifying image.
+        env_args = []
+        if env:
+            env_args = ['env'] + ["%s=%s" for k, v in env.items()]
 
-        @return_value: script output
-        """
-        return self.instance.run_script(*args, **kwargs)
+        mic_chroot = ['sudo', 'mount-image-callback', '--system-mounts',
+                      '--system-resolvconf', self._img_path,
+                      '--', 'chroot', '_MOUNTPOINT_']
+        try:
+            out, err = c_util.subp(mic_chroot + env_args + list(command),
+                                   data=stdin, decode=False)
+            return (out, err, 0)
+        except c_util.ProcessExecutionError as e:
+            return (e.stdout, e.stderr, e.exit_code)
 
     def snapshot(self):
         """Create snapshot of image, block until done."""
@@ -82,7 +77,6 @@ class NoCloudKVMImage(base.Image):
         framework decide whether to keep or destroy everything.
         """
         self._img_path = None
-        self._instance.destroy()
         super(NoCloudKVMImage, self).destroy()
 
 # vi: ts=4 expandtab