curtin-dev team mailing list archive

[Olivier Gayot <mp+413788@xxxxxxxxxxxxxxxxxx>]

Olivier Gayot has proposed merging ~ogayot/curtin:apt-pinning into curtin:master.

Requested reviews:
  curtin developers (curtin-dev)

For more details, see:
https://code.launchpad.net/~ogayot/curtin/+git/curtin/+merge/413788

Implement support for APT preferences in apt-config

apt-config now supports a set of APT preferences (i.e. pinning rules) as in the following example:

  apt:
    preferences:
      - {package: "python3-*", pin: "origin *ubuntu.com*", pin-priority: 200}
      - {package: "python-*", pin: "origin *ubuntu.com*", pin-priority: -1}

These preferences are deployed under <target>/etc/apt/preferences.d/90-curtin.pref using the format specified in apt_preferences(5).

  Package: python3-*
  Pin: origin *ubuntu.com*
  Pin-Priority: 200

  Package: python-*
  Pin: origin *ubuntu.com*
  Pin-Priority: -1

If no preferences are configured, we drop the file 90-curtin.pref if it exists.
-- 
Your team curtin developers is requested to review the proposed merge of ~ogayot/curtin:apt-pinning into curtin:master.

diff --git a/curtin/commands/apt_config.py b/curtin/commands/apt_config.py
index 9ea2d30..be4a039 100644
--- a/curtin/commands/apt_config.py
+++ b/curtin/commands/apt_config.py
@@ -28,6 +28,9 @@ APT_LISTS = "/var/lib/apt/lists"
 APT_CONFIG_FN = "/etc/apt/apt.conf.d/94curtin-config"
 APT_PROXY_FN = "/etc/apt/apt.conf.d/90curtin-aptproxy"
 
+# Files to store pinning information
+APT_PREFERENCES_FN = "/etc/apt/preferences.d/90curtin.pref"
+
 # Default keyserver to use
 DEFAULT_KEYSERVER = "keyserver.ubuntu.com"
 
@@ -81,6 +84,11 @@ def handle_apt(cfg, target=None):
     except (IOError, OSError):
         LOG.exception("Failed to apply proxy or apt config info:")
 
+    try:
+        apply_apt_preferences(cfg, target + APT_PREFERENCES_FN)
+    except (IOError, OSError):
+        LOG.exception("Failed to apply apt preferences.")
+
     # Process 'apt_source -> sources {dict}'
     if 'sources' in cfg:
         params = mirrors
@@ -595,6 +603,36 @@ def apply_apt_proxy_config(cfg, proxy_fname, config_fname):
         LOG.debug("no apt config configured, removed %s", config_fname)
 
 
+def preference_to_str(preference):
+    """ Return a textual representation of a given preference as specified in
+    apt_preferences(5).
+    """
+
+    return """\
+Package: {package}
+Pin: {pin}
+Pin-Priority: {pin_priority}
+""".format(package=preference["package"],
+           pin=preference["pin"],
+           pin_priority=preference["pin-priority"])
+
+
+def apply_apt_preferences(cfg, pref_fname):
+    """ Apply apt preferences if any is provided.
+    """
+
+    prefs = cfg.get("preferences")
+    if not prefs:
+        if os.path.isfile(pref_fname):
+            util.del_file(pref_fname)
+            LOG.debug("no apt preferences configured, removed %s", pref_fname)
+        return
+    prefs_as_strings = [preference_to_str(pref) for pref in prefs]
+    print(prefs_as_strings)
+    LOG.debug("write apt preferences info to %s.", pref_fname)
+    util.write_file(pref_fname, "\n".join(prefs_as_strings))
+
+
 def apt_command(args):
     """ Main entry point for curtin apt-config standalone command
         This does not read the global config as handled by curthooks, but
diff --git a/doc/topics/apt_source.rst b/doc/topics/apt_source.rst
index cf0f8bd..924ee80 100644
--- a/doc/topics/apt_source.rst
+++ b/doc/topics/apt_source.rst
@@ -31,6 +31,8 @@ Features
 
   - add arbitrary apt.conf settings
 
+  - add arbitrary apt preferences
+
   - provide debconf configurations
 
   - disabling suites (=pockets)
diff --git a/examples/apt-source.yaml b/examples/apt-source.yaml
index f0f7108..e9543ae 100644
--- a/examples/apt-source.yaml
+++ b/examples/apt-source.yaml
@@ -152,6 +152,18 @@ apt:
   # The following example is also the builtin default if nothing is specified
   add_apt_repo_match: '^[\w-]+:\w'
 
+  # 1.9 preferences
+  #
+  # Any apt preferences that will be made available to apt
+  # see the APT_PREFERENCES(5) man page for details about what can be specified
+  preferences:
+    - package: python3-*
+      pin: origin *ubuntu.com*
+      pin-priority: 200
+    - package: python-*
+      pin: origin *ubuntu.com*
+      pin-priority: -1
+
 
   ##############################################################################
   # Section 2: source list entries
diff --git a/tests/unittests/test_apt_source.py b/tests/unittests/test_apt_source.py
index 48fb820..267711f 100644
--- a/tests/unittests/test_apt_source.py
+++ b/tests/unittests/test_apt_source.py
@@ -572,6 +572,55 @@ class TestAptSourceConfig(CiTestCase):
                                     'Acquire::ftp::Proxy "foobar3";\n'
                                     'Acquire::https::Proxy "foobar4";\n'))
 
+    def test_preference_to_str(self):
+        """ test_preference_to_str - Test converting a preference dict to
+        textual representation.
+        """
+        preference = {
+            "package": "*",
+            "pin": "release a=unstable",
+            "pin-priority": 50,
+        }
+
+        expected = """\
+Package: *
+Pin: release a=unstable
+Pin-Priority: 50
+"""
+        self.assertEqual(expected, apt_config.preference_to_str(preference))
+
+    @staticmethod
+    def test_apply_apt_preferences():
+        """ test_apply_apt_preferences - Test apt preferences configuration
+        """
+        cfg = {
+            "preferences": [
+                {
+                    "package": "*",
+                    "pin": "release a=unstable",
+                    "pin-priority": 50,
+                }, {
+                    "package": "dummy-unwanted-package",
+                    "pin": "origin *ubuntu.com*",
+                    "pin-priority": -1,
+                }
+            ]
+        }
+
+        expected_content = """\
+Package: *
+Pin: release a=unstable
+Pin-Priority: 50
+
+Package: dummy-unwanted-package
+Pin: origin *ubuntu.com*
+Pin-Priority: -1
+"""
+        with mock.patch.object(util, "write_file") as mockobj:
+            apt_config.apply_apt_preferences(cfg, "preferencesfn")
+
+        mockobj.assert_called_with("preferencesfn", expected_content)
+
     def test_mirror(self):
         """test_mirror - Test defining a mirror"""
         pmir = "http://us.archive.ubuntu.com/ubuntu/";