Merge lp:~hloeung/ubuntu-repository-cache/system-mail-admin into lp:ubuntu-repository-cache

[Haw Loeung]

Allow specifying admin email for various system/root emails such as cron metadata sync failures

These are all all taken from the smtp-relay charm.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Thomas Cuthbert (tcuthbert)]

LGTM +1

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 354

=== modified file 'config.yaml'
--- config.yaml	2022-07-22 05:24:57 +0000
+++ config.yaml	2022-07-25 00:20:37 +0000
@@ -1,4 +1,9 @@
 options:
+  admin_email:
+    default: ""
+    type: string
+    description: |
+      Email to use to send mail.
   sync-host:
     default: archive.ubuntu.com
     type: string

=== modified file 'layer.yaml'
--- layer.yaml	2021-10-04 22:14:51 +0000
+++ layer.yaml	2022-07-25 00:20:37 +0000
@@ -6,6 +6,7 @@
 options:
   basic:
     packages:
+      - postfix
       - run-one
       - w3m
     # python3-apt isn't available via pip so we'll need to use system packages

=== modified file 'reactive/ubuntu_repository_cache.py'
--- reactive/ubuntu_repository_cache.py	2021-05-25 02:25:00 +0000
+++ reactive/ubuntu_repository_cache.py	2022-07-25 00:20:37 +0000
@@ -4,9 +4,11 @@
 This 'hooks' source constitutes all of the code for handle charm hooks.
 '''
 
+import grp
 import os
 import pwd
 import shutil
+import subprocess
 
 from charms import reactive
 from charms.layer import status
@@ -73,6 +75,9 @@
     # restart/reload apache at the same time.
     shutil.copy2('files/cron_random_sleep.sh', '/etc/cron.daily/000-cron-random-sleep')
 
+    config = hookenv.config()
+    _update_aliases(config['admin_email'])
+
     reactive.set_flag('ubuntu-repository-cache.configured')
 
 
@@ -314,3 +319,51 @@
         fname = os.path.join(ssh_dir, f)
         if os.path.exists(fname):
             os.chown(fname, uid, -1)
+
+
+def _write_file(source, dest_path, perms=0o644, owner=None, group=None):
+    """Write file only on changes and return True if changes written."""
+    # Compare and only write out file on change.
+    dest = ''
+
+    try:
+        with open(dest_path, 'r') as f:
+            dest = f.read()
+        if source == dest:
+            return False
+    except FileNotFoundError:
+        pass
+
+    if owner is None:
+        owner = pwd.getpwuid(os.getuid()).pw_name
+    if group is None:
+        group = grp.getgrgid(pwd.getpwnam(owner).pw_gid).gr_name
+
+    host.write_file(path=dest_path + '.new', content=source, perms=perms, owner=owner, group=group)
+    os.rename(dest_path + '.new', dest_path)
+    return True
+
+
+def _update_aliases(admin_email='', aliases_path='/etc/aliases'):
+
+    aliases = []
+    try:
+        with open(aliases_path, 'r') as f:
+            aliases = f.readlines()
+    except FileNotFoundError:
+        pass
+
+    new_aliases = []
+    for line in aliases:
+        if line.startswith('root:'):
+            continue
+        new_aliases.append(line)
+
+    if admin_email:
+        new_aliases.append('root:          {}\n'.format(admin_email))
+
+    changed = _write_file(''.join(new_aliases), aliases_path)
+    if changed:
+        subprocess.call(['newaliases'])
+
+    return

=== modified file 'tests/unit/test_ubuntu_repository_cache.py'
--- tests/unit/test_ubuntu_repository_cache.py	2021-03-08 20:55:34 +0000
+++ tests/unit/test_ubuntu_repository_cache.py	2022-07-25 00:20:37 +0000
@@ -1,4 +1,6 @@
+import grp
 import os
+import pwd
 import shutil
 import sys
 import tempfile
@@ -87,3 +89,87 @@
         status.active.reset_mock()
         ubuntu_repository_cache.set_active(os.path.join(self.charm_dir, 'tests/unit/files/version5'))
         status.active.assert_called_once_with('Ready (source version/commit commit-id)')
+
+    def test__write_file(self):
+        source = '# User-provided config added here'
+        dest = os.path.join(self.tmpdir, 'my-test-file')
+
+        self.assertTrue(ubuntu_repository_cache._write_file(source, dest))
+        # Write again, should return False and not True per above.
+        self.assertFalse(ubuntu_repository_cache._write_file(source, dest))
+
+        # Check contents
+        with open(dest, 'r') as f:
+            got = f.read()
+        self.assertEqual(got, source)
+
+    @mock.patch('charmhelpers.core.host.write_file')
+    @mock.patch('os.rename')
+    def test__write_file_owner_group(self, rename, write_file):
+        source = '# User-provided config added here'
+        dest = os.path.join(self.tmpdir, 'my-test-file')
+
+        self.assertTrue(ubuntu_repository_cache._write_file(source, dest, owner='root', group='root'))
+        want = [mock.call(path=dest + '.new', content=source, perms=420, owner='root', group='root')]
+        write_file.assert_has_calls(want, any_order=True)
+        self.assertEqual(len(want), len(write_file.mock_calls))
+
+        write_file.reset_mock()
+        with mock.patch('builtins.open', side_effect=FileNotFoundError):
+            ubuntu_repository_cache._write_file(source, dest, owner='root', group='root')
+        want = [mock.call(path=dest + '.new', content=source, perms=420, owner='root', group='root')]
+        write_file.assert_has_calls(want, any_order=True)
+        self.assertEqual(len(want), len(write_file.mock_calls))
+
+        write_file.reset_mock()
+        with mock.patch('builtins.open', side_effect=FileNotFoundError):
+            ubuntu_repository_cache._write_file(source, dest)
+        current_usr = pwd.getpwuid(os.getuid()).pw_name
+        current_grp = grp.getgrgid(pwd.getpwnam(current_usr).pw_gid).gr_name
+        want = [mock.call(path=dest + '.new', content=source, perms=420, owner=current_usr, group=current_grp)]
+        write_file.assert_has_calls(want, any_order=True)
+        self.assertEqual(len(want), len(write_file.mock_calls))
+
+        write_file.reset_mock()
+        with mock.patch('builtins.open', side_effect=FileNotFoundError):
+            ubuntu_repository_cache._write_file(source, dest, owner='nobody')
+        current_grp = grp.getgrgid(pwd.getpwnam('nobody').pw_gid).gr_name
+        want = [mock.call(path=dest + '.new', content=source, perms=420, owner='nobody', group=current_grp)]
+        write_file.assert_has_calls(want, any_order=True)
+        self.assertEqual(len(want), len(write_file.mock_calls))
+
+    @mock.patch('subprocess.call')
+    def test__update_aliases(self, call):
+        dest = os.path.join(self.tmpdir, 'aliases')
+
+        # Empty, does not exist.
+        ubuntu_repository_cache._update_aliases('', dest)
+        with open(dest, 'r', encoding='utf-8') as f:
+            got = f.read()
+        want = ''
+        self.assertEqual(want, got)
+        call.assert_called_with(['newaliases'])
+
+        # Admin email set.
+        call.reset_mock()
+        content = 'postmaster:    root\n'
+        with open(dest, 'w') as f:
+            f.write(content)
+        ubuntu_repository_cache._update_aliases('[e-mail]', dest)
+        want = 'postmaster:    root\nroot:          [e-mail]\n'
+        with open(dest, 'r', encoding='utf-8') as f:
+            got = f.read()
+        self.assertEqual(want, got)
+        call.assert_called_with(['newaliases'])
+
+        # Has admin email, so do nothing and do not call newaliases.
+        call.reset_mock()
+        content = 'postmaster:    root\nroot:          [e-mail]\n'
+        with open(dest, 'w') as f:
+            f.write(content)
+        ubuntu_repository_cache._update_aliases('[e-mail]', dest)
+        want = content
+        with open(dest, 'r', encoding='utf-8') as f:
+            got = f.read()
+        self.assertEqual(want, got)
+        call.assert_not_called()