meta: add base as a type and top level property (#1419)

demos/base-example-consumer/snap/snapcraft.yaml

@@ -0,0 +1,18 @@
+name: base-example-consumer
+version: 1.0
+summary: Example snap that consumes a different base snap
+description:
+  This example snap uses the base-example base snap instead of
+  the regular "core" snap.
+confinement: strict
+base: base-example
+
+apps:
+  hello:
+    command: usr/bin/hello
+
+parts:
+  libc:
+    plugin: dump
+    source: .
+    stage-packages: [hello]

demos/base-example/snap/snapcraft.yaml

@@ -0,0 +1,17 @@
+name: base-example
+version: 1.0
+summary: Example base snap
+description:
+  A base snap is a special kind of snap that can be used by
+  other snaps as an alternative base. This base will then
+  be used as the root filesystem instead of the traditional
+  core snap.
+
+  This example base snap only contains a basic libc6.
+type: base
+
+parts:
+  libc:
+    plugin: dump
+    source: .
+    stage-packages: [libc6]

schema/snapcraft.yaml

@@ -80,6 +80,7 @@ properties:
     description: the snap type, the implicit type is 'app'
     enum:
       - app
+      - base
       - gadget
       - kernel
       - os
@@ -104,6 +105,9 @@ properties:
     enum:
       - stable
       - devel
+  base:
+    type: string
+    description: the base snap to use
   epoch:
     description: the snap epoch, used to specify upgrade paths
     format: epoch

snapcraft/internal/meta.py

@@ -53,6 +53,7 @@
 _OPTIONAL_PACKAGE_KEYS = [
     'architectures',
     'assumes',
+    'base',
     'environment',
     'type',
     'plugs',

snapcraft/tests/commands/test_snap.py

@@ -100,7 +100,8 @@ def test_snap_fails_with_bad_type(self):
             self.run_command, ['snap'])
 
         self.assertThat(str(raised), Contains(
-            "bad-type' is not one of ['app', 'gadget', 'kernel', 'os']"))
+            "bad-type' is not one of ['app', 'base', 'gadget', "
+            "'kernel', 'os']"))
 
     def test_snap_is_the_default(self):
         self.make_snapcraft_yaml()

snapcraft/tests/test_project_loader.py

@@ -2063,7 +2063,7 @@ def test_invalid_types(self):
         expected_message = (
             "The 'type' property does not match the required "
             "schema: '{}' is not one of "
-            "['app', 'gadget', 'kernel', 'os']").format(self.type_)
+            "['app', 'base', 'gadget', 'kernel', 'os']").format(self.type_)
         self.assertEqual(raised.message, expected_message,
                          message=data)
 

snaps_tests/demos_tests/test_base-example.py

@@ -0,0 +1,29 @@
+# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
+#
+# Copyright (C) 2017 Canonical Ltd
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import snaps_tests
+
+
+class BaseExampleTestCase(snaps_tests.SnapsTestCase):
+
+    snap_content_dir = 'base-example'
+
+    def test_base_example(self):
+        # Build snap will raise an exception in case of error.
+        snap_path = self.build_snap(self.snap_content_dir)
+        # Install snap will raise an exception in case of error.
+        self.install_snap(snap_path, 'base-example', '1.0')
+        # more testing is done in test_base-consumer

snaps_tests/demos_tests/test_base-example_consumer.py

@@ -0,0 +1,33 @@
+# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
+#
+# Copyright (C) 2017 Canonical Ltd
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import snaps_tests
+
+
+class BaseExampleConsumerTestCase(snaps_tests.SnapsTestCase):
+
+    base_content_dir = 'base-example'
+    base_consumer_content_dir = 'base-example-consumer'
+
+    def test_base_example(self):
+        # build/install the alternative base
+        snap_path = self.build_snap(self.base_content_dir)
+        self.install_snap(snap_path, 'base-example', '1.0')
+        # build the consumer
+        snap_path = self.build_snap(self.base_consumer_content_dir)
+        self.install_snap(snap_path, 'base-example-consumer', '1.0')
+        # FIXME: once snapd supports bases fully run hello against
+        #        the alternative base